Effects of post-session administration of methylene blue on fear extinction and contextual memory in adults with claustrophobia.

PubMed

Telch, Michael J; Bruchey, Aleksandra K; Rosenfield, David; Cobb, Adam R; Smits, Jasper; Pahl, Sandra; Gonzalez-Lima, F

2014-10-01

Preclinical studies have shown that low-dose methylene blue increases mitochondrial cytochrome oxidase activity in the brain and improves memory retention after learning tasks, including fear extinction. The authors report on the first controlled experiment to examine the memory-enhancing effects of posttraining methylene blue administration on retention of fear extinction and contextual memory following fear extinction training. Adult participants displaying marked claustrophobic fear were randomly assigned to double-blind administration of 260 mg of methylene blue (N=23) or administration of placebo (N=19) immediately following six 5-minute extinction trials in an enclosed chamber. Retesting occurred 1 month later to assess fear renewal as indexed by peak fear during exposure to a nontraining chamber, with the prediction that the effects of methylene blue would vary as a function of fear reduction achieved during extinction training. Incidental contextual memory was assessed 1 and 30 days after training to assess the cognitive-enhancing effects of methylene blue independent of its effects on fear attenuation. Consistent with predictions, participants displaying low end fear posttraining showed significantly less fear at the 1-month follow-up if they received methylene blue posttraining compared with placebo. In contrast, participants displaying moderate to high levels of posttraining fear tended to fare worse at the follow-up if they received methylene blue posttraining. Methylene blue's enhancement of contextual memory was unrelated to initial or posttraining claustrophobic fear. Methylene blue enhances memory and the retention of fear extinction when administered after a successful exposure session but may have a deleterious effect on extinction when administered after an unsuccessful exposure session.

Methylene blue prevents retinal damage in an experimental model of ischemic proliferative retinopathy.

PubMed

Rey-Funes, Manuel; Larrayoz, Ignacio M; Fernández, Juan C; Contartese, Daniela S; Rolón, Federico; Inserra, Pablo I F; Martínez-Murillo, Ricardo; López-Costa, Juan J; Dorfman, Verónica B; Martínez, Alfredo; Loidl, César F

2016-06-01

Perinatal asphyxia induces retinal lesions, generating ischemic proliferative retinopathy, which may result in blindness. Previously, we showed that the nitrergic system was involved in the physiopathology of perinatal asphyxia. Here we analyze the application of methylene blue, a well-known soluble guanylate cyclase inhibitor, as a therapeutic strategy to prevent retinopathy. Male rats (n = 28 per group) were treated in different ways: 1) control group comprised born-to-term animals; 2) methylene blue group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery; 3) perinatal asphyxia (PA) group comprised rats exposed to perinatal asphyxia (20 min at 37°C); and 4) methylene blue-PA group comprised animals born from pregnant rats treated with methylene blue (2 mg/kg) 30 and 5 min before delivery, and then the pups were subjected to PA as above. For molecular studies, mRNA was obtained at different times after asphyxia, and tissue was collected at 30 days for morphological and biochemical analysis. Perinatal asphyxia produced significant gliosis, angiogenesis, and thickening of the inner retina. Methylene blue treatment reduced these parameters. Perinatal asphyxia resulted in a significant elevation of the nitrergic system as shown by NO synthase (NOS) activity assays, Western blotting, and (immuno)histochemistry for the neuronal isoform of NOS and NADPH-diaphorase activity. All these parameters were also normalized by the treatment. In addition, methylene blue induced the upregulation of the anti-angiogenic peptide, pigment epithelium-derived factor. Application of methylene blue reduced morphological and biochemical parameters of retinopathy. This finding suggests the use of methylene blue as a new treatment to prevent or decrease retinal damage in the context of ischemic proliferative retinopathy. Copyright © 2016 the American Physiological Society.

Methylene Blue Mitigates Acute Neuroinflammation after Spinal Cord Injury through Inhibiting NLRP3 Inflammasome Activation in Microglia.

PubMed

Lin, Zhi-Hang; Wang, Si-Yuan; Chen, Li-Li; Zhuang, Jia-Yuan; Ke, Qing-Feng; Xiao, Dan-Rui; Lin, Wen-Ping

2017-01-01

The spinal cord injury (SCI) is a detrimental neurological disease involving the primary mechanical injury and secondary inflammatory damage. Curtailing the detrimental neuroinflammation would be beneficial for spinal cord function recovery. Microglia reside in the spinal cord and actively participate in the onset, progression and perhaps resolution of post-SCI neuroinflammation. In the current study, we tested the effects of methylene blue on microglia both in vitro and in a rat SCI model. We found that methylene blue inhibited the protein levels of IL-1β and IL-18 rather than their mRNA levels in activated microglia. Further investigation indicated that methylene blue deceased the activation of NLRP3 inflammasome and NLRC4 inflammasome in microglia in vitro . Moreover, in the rat SCI model, the similar effect of methylene blue on post-SCI microglia was also observed, except that the activation of NLRC4 inflammasome was not seen. The inhibition of microglia NLRP3 inflammasome was associated with down-regulation of intracellular reactive oxygen species (ROS). The administration of methylene blue mitigated the overall post-SCI neuroinflammation, demonstrated by decreased pro-inflammatory cytokine production and leukocyte infiltrates. Consequently, the neuronal apoptosis was partially inhibited and the hind limb locomotor function was ameliorated by methylene blue treatment. Our research highlights the role of methylene blue in inhibiting post-SCI neuroinflammation, and suggests that methylene blue might be used for SCI therapy.

Methylene Blue Mitigates Acute Neuroinflammation after Spinal Cord Injury through Inhibiting NLRP3 Inflammasome Activation in Microglia

PubMed Central

Lin, Zhi-Hang; Wang, Si-Yuan; Chen, Li-Li; Zhuang, Jia-Yuan; Ke, Qing-Feng; Xiao, Dan-Rui; Lin, Wen-Ping

2017-01-01

The spinal cord injury (SCI) is a detrimental neurological disease involving the primary mechanical injury and secondary inflammatory damage. Curtailing the detrimental neuroinflammation would be beneficial for spinal cord function recovery. Microglia reside in the spinal cord and actively participate in the onset, progression and perhaps resolution of post-SCI neuroinflammation. In the current study, we tested the effects of methylene blue on microglia both in vitro and in a rat SCI model. We found that methylene blue inhibited the protein levels of IL-1β and IL-18 rather than their mRNA levels in activated microglia. Further investigation indicated that methylene blue deceased the activation of NLRP3 inflammasome and NLRC4 inflammasome in microglia in vitro. Moreover, in the rat SCI model, the similar effect of methylene blue on post-SCI microglia was also observed, except that the activation of NLRC4 inflammasome was not seen. The inhibition of microglia NLRP3 inflammasome was associated with down-regulation of intracellular reactive oxygen species (ROS). The administration of methylene blue mitigated the overall post-SCI neuroinflammation, demonstrated by decreased pro-inflammatory cytokine production and leukocyte infiltrates. Consequently, the neuronal apoptosis was partially inhibited and the hind limb locomotor function was ameliorated by methylene blue treatment. Our research highlights the role of methylene blue in inhibiting post-SCI neuroinflammation, and suggests that methylene blue might be used for SCI therapy. PMID:29311826

Effect of lipiodol and methylene blue on the thoracoscopic preoperative positioning.

PubMed

Zhang, Chuan-Yu; Yu, Hua-Long; Liu, Shi-He; Jiang, Gang; Wang, Yong-Jie

2015-01-01

The aim of this study was to compare and analyze the site-specific accuracy of mixture of lipiodol and methylene blue (MLM) (0.6 ml, 1:5) and pure methylene blue (0.5 ml) on the rabbit lungs. In this study, CT-guided percutaneous injection of MLM and methylene blue. Compare the staining degree by biopsy of lung tissue. Use 4 points system to evaluate the site-specific accuracy at 6h and 24 h after injection. For MLM, evaluate its radiopacity by radiation. When evaluate the positioning, 2 points mean acceptable, 3 points mean excellent. The results indicated that the staining range of MLM is obvious less than that of methylene blue (0.6 vs. 1.0 cm, P<0.01), but the staining capacity of MLM is higher than that of methylene blue (2.8 vs. 2.2, P = 0.01). About the staining abilities which are evaluated as excellent, MLM group accounts for 81%, methylene blue group accounts for 38% (P = 0.011). About the radiopacity which are evaluated as acceptable or excellent, MLM group accounts for 62%. With good direct vision, the suitable positioning rate of MLM can be 100%, which is better than that of methylene blue. In conclusion, percutaneous injection of MLM can be used to lung positioning. The result shows that use MLM is better than only using methylene blue. But it is necessary to do the investigation in human beings in order to confirm the feasibility of its clinical application.

Effect of lipiodol and methylene blue on the thoracoscopic preoperative positioning

PubMed Central

Zhang, Chuan-Yu; Yu, Hua-Long; Liu, Shi-He; Jiang, Gang; Wang, Yong-Jie

2015-01-01

The aim of this study was to compare and analyze the site-specific accuracy of mixture of lipiodol and methylene blue (MLM) (0.6 ml, 1:5) and pure methylene blue (0.5 ml) on the rabbit lungs. In this study, CT-guided percutaneous injection of MLM and methylene blue. Compare the staining degree by biopsy of lung tissue. Use 4 points system to evaluate the site-specific accuracy at 6h and 24 h after injection. For MLM, evaluate its radiopacity by radiation. When evaluate the positioning, 2 points mean acceptable, 3 points mean excellent. The results indicated that the staining range of MLM is obvious less than that of methylene blue (0.6 vs. 1.0 cm, P<0.01), but the staining capacity of MLM is higher than that of methylene blue (2.8 vs. 2.2, P = 0.01). About the staining abilities which are evaluated as excellent, MLM group accounts for 81%, methylene blue group accounts for 38% (P = 0.011). About the radiopacity which are evaluated as acceptable or excellent, MLM group accounts for 62%. With good direct vision, the suitable positioning rate of MLM can be 100%, which is better than that of methylene blue. In conclusion, percutaneous injection of MLM can be used to lung positioning. The result shows that use MLM is better than only using methylene blue. But it is necessary to do the investigation in human beings in order to confirm the feasibility of its clinical application. PMID:26221301

Serotonin syndrome following methylene blue administration during cardiothoracic surgery.

PubMed

Smith, Christina J; Wang, Dorothy; Sgambelluri, Anna; Kramer, Robert S; Gagnon, David J

2015-04-01

Despite its favorable safety profile, there have been reports of methylene blue-induced encephalopathy and serotonin syndrome in patients undergoing parathyroidectomy. We report a case of serotonin syndrome following methylene blue administration in a cardiothoracic surgery patient. A 59-year-old woman taking preoperative venlafaxine and trazodone was given a single dose of 2 mg/kg methylene blue (167 mg) during a planned coronary artery bypass and mitral valve repair. Postoperatively, she was febrile to 38.7°C and developed full-body tremors, rhythmic twitching of the perioral muscles, slow conjugate roving eye movements, and spontaneous movements of the upper extremities. Electroencephalography revealed generalized diffuse slowing consistent with toxic encephalopathy, and a computed tomography scan showed no acute process. The patient's symptoms were most consistent with a methylene blue-induced serotonin syndrome. Her motor symptoms resolved within 48 hours and she was eventually discharged home. Only 2 cases of methylene blue-induced serotonin syndrome during cardiothoracic surgery have been described in the literature, with this report representing the third case. Methylene blue and its metabolite, azure B, are potent, reversible inhibitors of monoamine oxidase A which is responsible for serotonin metabolism. Concomitant administration of methylene blue with serotonin-modulating agents may precipitate serotonin syndrome. © The Author(s) 2015.

International, prospective haemovigilance study on methylene blue-treated plasma.

PubMed

Noens, L; Vilariño, Ma D; Megalou, A; Qureshi, H

2017-05-01

Methylene blue is a phenothiazine dye, which in combination with visible light has virucidal and bactericidal properties, disrupting the replication of a broad range of enveloped viruses and some non-enveloped viruses. The study objective was to collect data on adverse reactions occurring with methylene blue plasma administered in a routine clinical practice environment and document their characteristics and severity. This was an open label, multicentre, non-controlled, non-randomized, non-interventional study. Patients who receive a methylene blue plasma transfusion were observed for any signs and symptoms (adverse reactions) within 24 h safter the start of the transfusion, in different hospitals for a study duration of at least 1 year. A total of 19 315 methylene blue plasma units were transfused. There were eight patients with adverse reactions recorded during the study, one of them serious. Two had more than one reaction (two and four, respectively). Three patients had previous transfusions with methylene blue plasma only. Methylene blue plasma has a very acceptable safety profile with a rate of serious adverse reactions of 0·5/10 000 units. © 2017 International Society of Blood Transfusion.

Improvement in Hemodynamics After Methylene Blue Administration in Drug-Induced Vasodilatory Shock: A Case Report.

PubMed

Laes, JoAn R; Williams, David M; Cole, Jon B

2015-12-01

The purpose of this study is to describe a case where methylene blue improved hemodynamics in a poisoned patient. This is a single case report where a poisoned patient developed vasodilatory shock following ingestion of atenolol, amlodipine, and valsartan. Shock persisted after multiple therapies including vasopressors, high-dose insulin, hemodialysis, and 20% intravenous fat emulsion. Methylene blue (2 mg/kg IV over 30 min) was administered in the ICU with temporal improvement as measured by pulmonary artery catheter hemodynamic data pre- and post-methylene blue administration. Within 1 h of methylene blue administration, systemic vascular resistance improved (240 dyn s/cm5 increased to 1204 dyn s/cm5), and vasopressor requirements decreased with maintenance of mean arterial pressure 60 mmHg. Methylene blue may improve hemodynamics in drug-induced vasodilatory shock and should be considered in critically ill patients poisoned with vasodilatory medications refractory to standard therapies.

Neurometabolic mechanisms for memory enhancement and neuroprotection of methylene blue

PubMed Central

Rojas, Julio C.; Bruchey, Aleksandra K.; Gonzalez-Lima, F.

2011-01-01

This paper provides the first review of the memory-enhancing and neuroprotective metabolic mechanisms of action of methylene blue in vivo. These mechanisms have important implications as a new neurobiological approach to improve normal memory and to treat memory impairment and neurodegeneration associated with mitochondrial dysfunction. Methylene blue’s action is unique because its neurobiological effects are not determined by regular drug-receptor interactions or drug-response paradigms. Methylene blue shows a hormetic dose-response, with opposite effects at low and high doses. At low doses, methylene blue is an electron cycler in the mitochondrial electron transport chain, with unparalleled antioxidant and cell respiration-enhancing properties that affect the function of the nervous system in a versatile manner. A major role of the respiratory enzyme cytochrome oxidase on the memory-enhancing effects of methylene blue is supported by available data. The memory-enhancing effects have been associated with improvement of memory consolidation in a network-specific and use-dependent fashion. In addition, low doses of methylene blue have also been used for neuroprotection against mitochondrial dysfunction in humans and experimental models of disease. The unique auto-oxidizing property of methylene blue and its pleiotropic effects on a number of tissue oxidases explain its potent neuroprotective effects at low doses. The evidence reviewed supports a mechanistic role of low-dose methylene blue as a promising and safe intervention for improving memory and for the treatment of acute and chronic conditions characterized by increased oxidative stress, neurodegeneration and memory impairment. PMID:22067440

Computed tomography guided percutaneous injection of a mixture of lipiodol and methylene blue in rabbit lungs: evaluation of localization ability for video-assisted thoracoscopic surgery.

PubMed

Jin, Kwang Nam; Lee, Kyung Won; Kim, Tae Jung; Song, Yong Sub; Kim, Dong Il

2014-01-01

Preoperative localization is necessary prior to video assisted thoracoscopic surgery for the detection of small or deeply located lung nodules. We compared the localization ability of a mixture of lipiodol and methylene blue (MLM) (0.6 mL, 1:5) to methylene blue (0.5 mL) in rabbit lungs. CT-guided percutaneous injections were performed in 21 subjects with MLM and methylene blue. We measured the extent of staining on freshly excised lung and evaluated the subjective localization ability with 4 point scales at 6 and 24 hr after injections. For MLM, radio-opacity was evaluated on the fluoroscopy. We considered score 2 (acceptable) or 3 (excellent) as appropriate for localization. The staining extent of MLM was significantly smaller than methylene blue (0.6 vs 1.0 cm, P<0.001). MLM showed superior staining ability over methylene blue (2.8 vs 2.2, P=0.010). Excellent staining was achieved in 17 subjects (81%) with MLM and 8 (38%) with methylene blue (P=0.011). An acceptable or excellent radio-opacity of MLM was found in 13 subjects (62%). An appropriate localization rate of MLM was 100% with the use of the directly visible ability and radio-opacity of MLM. MLM provides a superior pulmonary localization ability over methylene blue.

Effect of ultrasound sonication on clonogenic survival and mitochondria of ovarian cancer cells in the presence of methylene blue.

PubMed

Xiang, Junyan; Leung, Albert Wingnang; Xu, Chuanshan

2014-10-01

This study aimed to investigate the effect of ultrasound sonication in the presence of methylene blue on clonogenic survival and mitochondria of ovarian cancer cells. Human ovarian cancer HO-8910 cells, which were incubated with different concentrations of methylene blue for 1 hour, were exposed to an ultrasonic wave for 5 seconds with intensity of 0.46 W/cm(2). Clonogenic survival of HO-8910 cells after ultrasound sonication was measured by a colony-forming unit assay. Mitochondrial structural changes were observed on transmission electron microscopy, and the mitochondrial membrane potential was evaluated by confocal laser-scanning microscopy with rhodamine 123 staining. The colony-forming units of HO-8910 cells decreased considerably after ultrasound sonication in the presence of methylene blue. Transmission electron microscopy showed slightly enlarged mitochondria in the ultrasound-treated cells in the absence of methylene blue; however, seriously damaged mitochondria, even with almost complete disappearance of cristae, were found in the cells treated by ultrasound sonication in the presence of methylene blue. The mitochondrial membrane potential collapsed significantly when HO-8910 cells were treated by ultrasound sonication in the presence of methylene blue (P < .05). Ultrasound sonication in the presence of methylene blue markedly damaged mitochondrial structure and function and decreased clonogenic survival of HO-8910 cells. © 2014 by the American Institute of Ultrasound in Medicine.

Computed Tomography Guided Percutaneous Injection of a Mixture of Lipiodol and Methylene Blue in Rabbit Lungs: Evaluation of Localization Ability for Video-Assisted Thoracoscopic Surgery

PubMed Central

Jin, Kwang Nam; Kim, Tae Jung; Song, Yong Sub; Kim, Dong Il

2014-01-01

Preoperative localization is necessary prior to video assisted thoracoscopic surgery for the detection of small or deeply located lung nodules. We compared the localization ability of a mixture of lipiodol and methylene blue (MLM) (0.6 mL, 1:5) to methylene blue (0.5 mL) in rabbit lungs. CT-guided percutaneous injections were performed in 21 subjects with MLM and methylene blue. We measured the extent of staining on freshly excised lung and evaluated the subjective localization ability with 4 point scales at 6 and 24 hr after injections. For MLM, radio-opacity was evaluated on the fluoroscopy. We considered score 2 (acceptable) or 3 (excellent) as appropriate for localization. The staining extent of MLM was significantly smaller than methylene blue (0.6 vs 1.0 cm, P<0.001). MLM showed superior staining ability over methylene blue (2.8 vs 2.2, P=0.010). Excellent staining was achieved in 17 subjects (81%) with MLM and 8 (38%) with methylene blue (P=0.011). An acceptable or excellent radio-opacity of MLM was found in 13 subjects (62%). An appropriate localization rate of MLM was 100% with the use of the directly visible ability and radio-opacity of MLM. MLM provides a superior pulmonary localization ability over methylene blue. PMID:24431917

[Not Available].

PubMed

Charbonneau, Annie

2013-07-01

Methylene blue is used in medical practice for various reasons. Recent findings point to a potential interaction with serotonin reuptake inhibitors (SRIs) that could lead to serotonergic toxicity. To describe the risk of serotonergic toxicity associated with the interaction between methylene blue and SRIs. Relevant publications were searched systematically via MEDLINE (1946 to March 21, 2013) and Embase (1974 to 2013, week 11) with the following search terms: "methylene blue", "methylthioninium", "monoamine oxidase inhibitors", "serotonin reup-take inhibitors", and "serotonin syndrome". No restrictions were applied in relation to the indication for methylene blue or the language of publication. The reference lists of identified articles were also searched. Eighteen case reports and 2 case series were identified for inclusion. To date, no randomized controlled trials have been published. The first case report indicating suspicion of an interaction between methylene blue and SRIs was published in 2003. Seventeen other case reports describing the same type of interaction have been published since then. The 2 case series provided data from about 325 parathyroidectomies in which methylene blue was used for staining. The 17 patients who experienced central nervous system toxicity were all taking SRIs in the preoperative period. When administered in combination with SRIs, methylene blue may lead to serotonergic toxicity at doses as low as 0.7 mg/kg. Methylene blue would seem to have monoamine oxidase A inhibitory properties. Precautions should be taken to avoid this interaction. [Publisher's translation].

Better detection of Demodex mites by Löffler's alkaline methylene blue staining in patients with blepharitis.

PubMed

Kiuchi, Katsuji

2018-01-01

To determine whether the Löffler's alkaline methylene blue staining method is better than no staining in detecting Demodex mites in the eyelashes of patients with blepharitis. Eyelashes were collected from 22 patients with blepharitis. The mean age of the patients was 82.5±6.2 years (± SD) with a range from 71 to 93 years. Eyelashes were epilated by forceps and placed individually on microscope slides. The number of Demodex mites was determined by conventional optical microscopy before and immediately after the addition of the methylene blue staining solution. The mean Demodex count before the addition of the methylene blue solution was 2.9±2.9, and it was 4.4±3.9 after the addition of the methylene blue solution ( P <0.01, Wilcoxon test). The methylene blue staining method is a simple and useful method in detecting the presence and quantifying the number of Demodex mites. We recommend the methylene blue staining method not only for the diagnosis of the presence of Demodex mites but also to evaluate the therapeutic effects of medications to eliminate the mite infestation.

Better detection of Demodex mites by Löffler’s alkaline methylene blue staining in patients with blepharitis

PubMed Central

Kiuchi, Katsuji

2018-01-01

Purpose To determine whether the Löffler’s alkaline methylene blue staining method is better than no staining in detecting Demodex mites in the eyelashes of patients with blepharitis. Materials and methods Eyelashes were collected from 22 patients with blepharitis. The mean age of the patients was 82.5±6.2 years (± SD) with a range from 71 to 93 years. Eyelashes were epilated by forceps and placed individually on microscope slides. The number of Demodex mites was determined by conventional optical microscopy before and immediately after the addition of the methylene blue staining solution. Results The mean Demodex count before the addition of the methylene blue solution was 2.9±2.9, and it was 4.4±3.9 after the addition of the methylene blue solution (P<0.01, Wilcoxon test). Conclusion The methylene blue staining method is a simple and useful method in detecting the presence and quantifying the number of Demodex mites. We recommend the methylene blue staining method not only for the diagnosis of the presence of Demodex mites but also to evaluate the therapeutic effects of medications to eliminate the mite infestation. PMID:29713140

[Injection of methylene blue into inferior mesenteric artery improves lymph node harvest in rectal cancer after neoadjuvant chemotherapy].

PubMed

Liu, Jianpei; Huang, Pinjie; Huang, Jianglong; Chen, Tufeng; Wei, Hongbo

2015-06-09

To confirm the feasibility of improving lymph node harvest by injecting methylene blue into inferior mesenteric artery in rectal cancer after neoadjuvant therapy. Forty two ex vivo specimens were collected from rectal cancer patients with neoadjuvant therapy and radical operation at our hospital. Traditional method with palpation and injection of methylene blue into inferior mesenteric artery were employed. The data of lymph node harvest were analyzed by paired t and chi-square tests. The average number of detected lymph node in traditional method and methylene blue groups were 6.1 ± 4.3 and 15.2 ± 6.4 respectively (P<0.001). The proportions of lymph nodes <5 mm were 14.1% and 46.7% in traditional method and methylene blue groups respectively (P<0.001). And the injection of methylene blue added 13 extra metastatic lymph nodes and caused a shift to node-positive stage (P=0.89). Neoadjuvant therapy decrease lymph node retrieval in rectal cancer. Injecting methylene blue into inferior mesenteric artery improves lymph node harvest especially for small nodes and helps to acquire more metastatic nodes for accurate pathological staging.

Post-Session Administration of USP Methylene Blue Facilitates the Retention of Pathological Fear Extinction and Contextual Memory in Phobic Adults

PubMed Central

Telch, Michael J.; Bruchey, Aleksandra K.; Rosenfield, David; Cobb, Adam R.; Smits, Jasper; Pahl, Sandra; Gonzalez-Lima, F.

2015-01-01

Objective Preclinical studies have shown that low-dose USP methylene blue increases mitochondrial cytochrome oxidase activity in the brain and improves memory retention after learning tasks, including fear extinction. We report on the first controlled experiment to examine the memory-enhancing effects of post-training methylene blue administration on retention of fear extinction and contextual memory following fear extinction training. Method Adults (N = 42) displaying marked claustrophobic fear were randomized to double-blind administration of 260 mg of methylene blue versus placebo immediately following six five-minute extinction trials to an enclosed chamber. Retesting occurred one month later to assess fear renewal as indexed by peak fear during exposure to a non-trained enclosed chamber with the prediction that methylene blue's effects would vary as a function of fear reduction achieved during extinction training. Incidental contextual memory was assessed 1 and 30 days after training to assess the cognitive enhancing effects of methylene blue independent of its effects on fear attenuation. Results Consistent with predictions, participants displaying low end fear at post-training showed significantly less fear at follow-up if they received methylene blue post-training relative to placebo. In contrast, participants displaying moderate to high levels of post-training fear tended to fare worse at follow-up relative to placebo. Methylene blue's enhancement of contextual memory was unrelated to initial or post-training claustrophobic fear. Conclusions Methylene blue enhances memory and the retention of fear extinction when administered after a successful exposure session, but may have a deleterious effect on extinction when administered after an unsuccessful exposure session. PMID:25018057

Bactericide effect of methylene blue associated with low-level laser therapy in Escherichia coli bacteria isolated from pressure ulcers.

PubMed

Gomes, Thais Ferreira; Pedrosa, Matheus Masalskiene; de Toledo, Ana Claudia Laforga; Arnoni, Veridiana Wanshi; Dos Santos Monteiro, Mirian; Piai, Davi Cury; Sylvestre, Silvia Helena Zacarias; Ferreira, Bruno

2018-05-09

The present study analyzed the bactericidal effect of methylene blue associated with low-level lasers on Escherichia coli isolated from a pressure ulcer. Microbiological material from a pressure ulcer was isolated using an aseptic swab, and antimicrobial activity was verified using the diffusion disc method. Methylene blue was used at concentrations of 0.001 and 0.005%, and low-level lasers of 670, 830, and 904 nm, with the energy densities of 4, 8, 10, and 14 J/cm 2 , were tested on three plates each and combined with methylene blue of each concentration. In addition, three control plates were used, with each concentration and energy density separated without any interventions. The results were analyzed using the paired sample t test to determine the bactericidal effect of the methylene blue and using the ANOVA test to compare the effects of the energy densities and wavelengths among the low-level laser treatment protocols. The results showed bacterial reduction at wavelengths of 830 and 904 nm and more proliferation in wavelengths of 670 nm. In wavelength of 830 nm, a bacterial reduction was observed in the conditions with 0.001% methylene blue in all energy density utilized, with 0.005% methylene blue in energy density of 10 J/cm 2 , and without methylene blue in energy density at 10 J/cm 2 . And in a wavelength of 904 nm, all condition showed bacterial reduction with or without methylene blue. We concluded that the low-level lasers of 904 and 830 nm have bactericidal effects and at better energy densities (10 and 14 J/cm 2 ).

Methylene Blue to Treat Protamine-induced Anaphylaxis Reactions. An Experimental Study in Pigs.

PubMed

Albuquerque, Agnes Afrodite S; Margarido, Edson A; Menardi, Antonio Carlos; Scorzoni, Adilson; Celotto, Andrea Carla; Rodrigues, Alfredo J; Vicente, Walter Vilella A; Evora, Paulo Roberto B

2016-01-01

To examine if methylene blue (MB) can counteract or prevent protamine (P) cardiovascular effects. The protocol included five heparinized pig groups: Group Sham -without any drug; Group MB - MB 3 mg/kg infusion; Group P - protamine; Group P/MB - MB after protamine; Group MB/P - MB before protamine. Nitric oxide levels were obtained by the nitric oxide/ozone chemiluminescence method, performed using the Nitric Oxide Analizer 280i (Sievers, Boulder, CO, USA). Malondialdehyde plasma levels were estimated using the thiobarbiturate technique. 1) Groups Sham and MB presented unchanged parameters; 2) Group P - a) Intravenous protamine infusion caused mean arterial pressure decrease and recovery trend after 25-30 minutes, b) Cardiac output decreased and remained stable until the end of protamine injection, and c) Sustained systemic vascular resistance increased until the end of protamine injection; 3) Methylene blue infusion after protamine (Group P/MB) - a) Marked mean arterial pressure decreased after protamine, but recovery after methylene blue injection, b) Cardiac output decreased after protamine infusion, recovering after methylene blue infusion, and c) Sustained systemic vascular resistance increased after protamine infusion and methylene blue injections; 4) Methylene blue infusion before protamine (Group MB/P) - a) Mean arterial pressure decrease was less severe with rapid recovery, b) After methylene blue, there was a progressive cardiac output increase up to protamine injection, when cardiac output decreased, and c) Sustained systemic vascular resistance decreased after protamine, followed by immediate Sustained systemic vascular resistance increase; 5) Plasma nitrite/nitrate and malondialdehyde values did not differ among the experimental groups. Reviewing these experimental results and our clinical experience, we suggest methylene blue safely prevents and treats hemodynamic protamine complications, from the endothelium function point of view.

Emulsion liquid membrane for textile dye removal: Stability study

NASA Astrophysics Data System (ADS)

Kusumastuti, Adhi; Syamwil, Rodia; Anis, Samsudin

2017-03-01

Although textile dyes is basically available in very low concentration; it should be removed due to the toxicity to human body and environment. Among the existing methods, emulsion liquid membrane (ELM) is a promising method by providing high interfacial area and the ability to remove a very low concentration of the solute. The optimal emulsions were produced using commercially supplied homogeniser. The drop size was measured by the aid of microscope and image J software. Initially, methylene blue in simulated wastewater was extracted using a stirrer. Methylene blue concentration was determined using spectrophotometer. The research obtained optimal emulsion at surfactant concentration of 4 wt. %, kerosene as diluent, emulsification time of 30 min, emulsification speed of 2000 rpm. The lowest membrane breakage and the longest stability time were about 0.11% and 150 min, respectively.

21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used... Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under... inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of orally...

21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used... Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under... inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of orally...

21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used... Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under... inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of orally...

21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-antispasmodic preparations that contained methylene blue cause Heinz body hemolytic anemia in cats when used... Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under... inclusion bodies (Heinz bodies) and associated hemolytic anemia is unclear. (2) The effectiveness of orally...

Safety of methylene blue dye for lymphatic mapping in patients taking selective serotonin reuptake inhibitors.

PubMed

Shah-Khan, Miraj G; Lovely, Jenna; Degnim, Amy C

2012-11-01

Methylene blue dye has an important role in lymphatic mapping for sentinel lymph node surgery. A recent safety announcement from the US Food and Drug Administration warned physicians about possible serious central nervous system reactions in patients on serotonergic medications who received intravenous methylene blue for the identification of parathyroid glands. This report summarizes evidence from the Food and Drug Administration's announcement and methylene blue pharmacokinetics. The authors conclude that the use of methylene blue dye at low doses for lymphatic mapping likely carries very little risk for serotonin neurotoxicity, although breast surgeons should be aware of this potential complication in the event of mental status or neuromuscular changes in patients after lymphatic mapping. Copyright © 2012 Elsevier Inc. All rights reserved.

Methylene Blue: The Long and Winding Road From Stain to Brain: Part 2.

PubMed

Howland, Robert H

2016-10-01

Methylene blue was the first synthetic drug ever used in medicine, having been used to treat clinical pain syndromes, malaria, and psychotic disorders more than one century ago. Methylene blue is a cationic thiazine dye with redox-cycling properties and a selective affinity for the nervous system. This drug also inhibits the activity of monoamine oxidase, nitric oxide synthase, and guanylyl cyclase, as well as tau protein aggregation; increases the release of neurotransmitters, such as serotonin and norepinephrine; reduces amyloid-beta levels; and increases cholinergic transmission. The action of methylene blue on multiple cellular and molecular targets justifies its investigation in various neuropsychiatric disorders. Investigations of methylene blue were instrumental in the serendipitous development of phenothiazine antipsychotic drugs. Although chlorpromazine is heralded as the first antipsychotic drug used in psychiatry, methylene blue is a phenothiazine drug that had been used to treat psychotic patients half a century earlier. It has also been studied in bipolar disorder and deserves further investigation for the treatment of unipolar and bipolar disorders. More recently, methylene blue has been the subject of preclinical and clinical investigations for cognitive dysfunction, dementia, and other neurodegenerative disorders. [Journal of Psychosocial Nursing and Mental Health Services, 54(10), 21-26.]. Copyright 2016, SLACK Incorporated.

The Blue Coma: The Role of Methylene Blue in Unexplained Coma After Cardiac Surgery.

PubMed

Martino, Enrico Antonio; Winterton, Dario; Nardelli, Pasquale; Pasin, Laura; Calabrò, Maria Grazia; Bove, Tiziana; Fanelli, Giovanna; Zangrillo, Alberto; Landoni, Giovanni

2016-04-01

Methylene blue commonly is used as a dye or an antidote, but also can be used off label as a vasopressor. Serotonin toxicity is a potentially lethal and often misdiagnosed condition that can result from drug interaction. Mild serotonin toxicity previously was reported in settings in which methylene blue was used as a dye. The authors report 3 cases of life-threatening serotonin toxicity in patients undergoing chronic selective serotonin reuptake inhibitor (SSRI) therapy who also underwent cardiac surgery and received methylene blue to treat vasoplegic syndrome. An observational study. A cardiothoracic intensive care unit (ICU) in a teaching hospital. Three patients who received methylene blue after cardiac surgery, later discovered to be undergoing chronic SSRI therapy. None. All 3 patients received high doses of fentanyl during general anesthesia. They all developed vasoplegic syndrome and consequently were given methylene blue in the ICU. All 3 patients developed serotonin toxicity, including coma, after this administration and diagnostic tests were negative for acute intracranial pathology. Coma lasted between 1 and 5 days. Two patients were discharged from the ICU shortly after awakening, whereas the third patient experienced a complicated postoperative course for concomitant refractory low-cardiac-output syndrome. Patients undergoing chronic SSRI therapy should not be administered methylene blue to treat vasoplegic syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

Sentinel lymph node detection using methylene blue in patients with early stage cervical cancer.

PubMed

Yuan, Song-Hua; Xiong, Ying; Wei, Mei; Yan, Xiao-Jian; Zhang, Hui-Zhong; Zeng, Yi-Xin; Liang, Li-Zhi

2007-07-01

To evaluate the feasibility of sentinel lymph node (SLN) detection in patients with cervical cancer using the low-cost methylene blue dye and to optimize the application procedure. Patients with stage Ib(1)-IIa cervical cancer and subjected to abdominal radical abdominal hysterectomy and pelvic lymphadenectomy were enrolled. Methylene blue, 2-4 ml, was injected into the cervical peritumoral area in 77 cases (4 ml patent blue in the other four cases) 10-360 min before the incision, and surgically removed lymph nodes were examined for the blue lymph nodes that were considered as SLNs. High SLN detection rate was successfully achieved when 4 ml of methylene blue was applied (93.9%, 46/49). Bilaterally SLN detection rate was significantly higher (78.1% vs. 47.1% P=0.027) in cases when the timing of application was more than 60 min before surgery than those with timing no more than 30 min. The blue color of methylene blue-stained SLNs sustained both in vivo and ex vivo, compared with the gradually faded blue color of patent blue that detected in 3 of 4 cases unilaterally. In the total of 112 dissected sides, the most common location of SLNs was the obturator basin (65.2%, 73/112), followed by external iliac area (30.4%, 34/112) and internal iliac area (26.8%, 30/112). Three patients who gave false negative results all had enlarged nodes. Methylene blue is an effective tracer to detect SLNs in patients with early stage cervical cancer. The ideal dose and timing of methylene blue application are 4 ml and 60-90 min prior surgery, respectively.

Corneal edema and permanent blue discoloration of a silicone intraocular lens by methylene blue.

PubMed

Stevens, Scott; Werner, Liliana; Mamalis, Nick

2007-01-01

To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye. A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion. The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations. This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

[The clinical value of sentinel lymph node detection in laryngeal and hypopharyngeal carcinoma patients with clinically negative neck by methylene blue method and radiolabeled tracer method].

PubMed

Zhao, Xin; Xiao, Dajiang; Ni, Jianming; Zhu, Guochen; Yuan, Yuan; Xu, Ting; Zhang, Yongsheng

2014-11-01

To investigate the clinical value of sentinel lymph node (SLN) detection in laryngeal and hypopharyngeal carcinoma patients with clinically negative neck (cN0) by methylene blue method, radiolabeled tracer method and combination of these two methods. Thirty-three patients with cN0 laryngeal carcinoma and six patients with cN0 hypopharyngeal carcinoma underwent SLN detection using both of methylene blue and radiolabeled tracer method. All these patients were accepted received the injection of radioactive isotope 99 Tc(m)-sulfur colloid (SC) and methylene blue into the carcinoma before surgery, then all these patients underwent intraopertive lymphatic mapping with a handheld gamma-detecting probe and blue-dyed SLN. After the mapping of SLN, selected neck dissections and tumor resections were peformed. The results of SLN detection by radiolabeled tracer, dye and combination of both methods were compared. The detection rate of SLN by radiolabeled tracer, methylene blue and combined method were 89.7%, 79.5%, 92.3% respectively. The number of detected SLN was significantly different between radiolabeled tracer method and combined method, and also between methylene blue method and combined method. The detection rate of methylene blue and radiolabeled tracer method were significantly different from combined method (P < 0.05). Nine patients were found to have lymph node metastasis by final pathological examination. The accuracy and negative rate of SLN detection of the combined method were 97.2% and 11.1%. The combined method using radiolabeled tracer and methylene blue can improve the detection rate and accuracy of sentinel lymph node detection. Furthermore, sentinel lymph node detection can accurately represent the cervical lymph node status in cN0 laryngeal and hypopharyngeal carcinoma.

Effectiveness of purified methylene blue in an experimental model of Mycobacterium ulcerans infection.

PubMed

Tian, Roger B D; Asmar, Shady; Napez, Claude; Lépidi, Hubert; Drancourt, Michel

2017-03-01

Mycobacterium ulcerans is responsible for Buruli ulcer, characterised by extensive, disabling ulcers. Standard treatment combining rifampicin and streptomycin exposes patients to toxicity and daily painful injections. In this study, the in vitro susceptibilities of 3 M. ulcerans strains, 1 Mycobacterium marinum strain and 18 strains representative of eleven other Mycobacterium species and subspecies to methylene blue were determined. Whilst growth of M. ulcerans was inhibited by 0.0125 g/L methylene blue, growth of all other tested strains was not inhibited by 1 g/L methylene blue. The effectiveness of methylene blue in a murine model of M. ulcerans infection was then tested. Topical treatment by brushing a methylene blue solution on the skin lesion, systemic treatment by intraperitoneal injection of methylene blue, and a combined treatment (topical and systemic) were tested. The three treatment groups exhibited a significantly lower clinical score compared with the non-treated control group (P <0.05). Moreover, subcutaneous nodules were significantly smaller in the systemic treatment group (excluding males) (3 ± 0.7 mm) compared with the other groups (P <0.05). The M. ulcerans insertion sequence IS2404 and the KR-B gene were detected in all challenged mice, but not in negative controls. The density of M. ulcerans (mycobacteria/cell) was significantly lower in the combined treatment group compared with the other groups. These data provide evidence for the effectiveness of purified methylene blue against the initial stage of Buruli ulcer. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Randomized single-blind clinical trial of intradermal methylene blue on pain reduction after open diathermy haemorrhoidectomy.

PubMed

Sim, H-L; Tan, K-Y

2014-08-01

Open haemorrhoidectomy has been associated with considerable postoperative pain and discomfort. Perianal intradermal injection of methylene blue has been shown to ablate perianal nerve endings and may bring about temporary pain relief after haemorrhoidectomy. We hypothesized that the administration of intradermal methylene blue would reduce postoperative pain during the initial period after surgery. A randomized, prospective, single-blind placebo-controlled trial was conducted. Patients were randomized to intradermal injection at haemorrhoidectomy of either 4 ml 1% methylene blue and 16 ml 0.5% marcaine or of 16 ml 0.5% marcaine and 4 ml saline prior to surgical dissection. Patients were asked to fill in a pain diary with a visual analogue scale. The primary outcome measure was pain score and analgesic use. Secondary outcomes were complications. There were 37 patients in the methylene blue arm and 30 patients in the placebo arm. There were no statistically significant differences in the sex, type of haemorrhoid, number of haemorrhoids excised, duration of surgery or hospital stay. The mean pain scores were significantly lower and the use of paracetamol was also significantly less in the methylene blue group during the first three postoperative days. The risk ratio of acute urinary retention occurring when methylene blue was not used was 2.320 (95% CI 1.754-3.067). Other complication rates were not significantly different. Perianal intradermal injection of methylene blue was useful in reducing the initial postoperative pain of open haemorrhoidectomy. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

21 CFR 500.27 - Methylene blue-containing drugs for use in animals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... according to label directions. The specific cause of the reaction was determined to be the methylene blue contained in the preparations. The reaction can be severe enough to cause death of treated animals. (ii) The Heinz body hemolytic anemia reaction to methylene blue has also been demonstrated in dogs under...

Fast photocatalytic degradation of methylene blue dye using a low-power diode laser.

PubMed

Liu, Xianhua; Yang, Yulou; Shi, Xiaoxuan; Li, Kexun

2015-01-01

This study focused on the application of diode lasers as alternative light sources for the fast photocatalytic degradation of methylene blue. The photocatalytic decomposition of methylene blue in aqueous solution under 443 nm laser light irradiation was found to be technically feasible using Ag/AgCl nanoparticles as photocatalysts. The effects of various experimental parameters, such as irradiation time, light source, catalyst loading, initial dye concentration, pH, and laser energy on decolorization and degradation were investigated. The mineralization of methylene blue was confirmed by chemical oxygen demand analysis. The results demonstrate that the laser-induced photocatalytic process can effectively degrade methylene blue under the optimum conditions (pH 9.63, 4 mg/L MB concentration, and 1.4 g/L Ag/AgCl nanoparticles). Copyright © 2014 Elsevier B.V. All rights reserved.

Methylene Blue for Vasoplegia When on Cardiopulmonary Bypass During Double-Lung Transplantation.

PubMed

Carley, Michelle; Schaff, Jacob; Lai, Terrance; Poppers, Jeremy

2015-10-15

Vasoplegia syndrome, characterized by hypotension refractory to fluid resuscitation or high-dose vasopressors, low systemic vascular resistance, and normal-to-increased cardiac index, is associated with increased morbidity and mortality after cardiothoracic surgery. Methylene blue inhibits inducible nitric oxide synthase and guanylyl cyclase, and has been used to treat vasoplegia during cardiopulmonary bypass. However, because methylene blue is associated with increased pulmonary vascular resistance, its use in patients undergoing lung transplantion has been limited. Herein, we report the use of methylene blue to treat refractory vasoplegia during cardiopulmonary bypass in a patient undergoing double-lung transplantation.

Efficacy of Methylene Blue in an Experimental Model of Calcium Channel Blocker Induced Shock

PubMed Central

Jang, David H.; Donovan, Sean; Nelson, Lewis S.; Bania, Theodore C.; Hoffman, Robert S.; Chu, Jason

2014-01-01

BACKGROUND Calcium channel blocker poisonings account for a substantial number of reported deaths from cardiovascular drugs. While supportive care is the mainstay of treatment, experimental therapies such as high dose insulin-euglycemia and lipid emulsion have been studied in animal models and used in humans. In the most severe cases even aggressive care is inadequate and deaths occur. In both experimental models and clinical cases of vasodilatory shock, methylene blue improves hemodynamic measures. Methylene blue acts as both a nitric oxide scavenger and inhibits guanylate cyclase that is responsible for the production of cGMP. Excessive cGMP production is associated with refractory vasodilatory shock in sepsis and anaphylaxis. The aim of this study was to determine the efficacy of methylene blue in an animal model of amlodipine-induced shock. METHODS Sprague-Dawley rats were anesthetized, ventilated and instrumented for continuous blood pressure and heart rate monitoring. The dose of amlodipine that produced death within 60 minutes was 17 mg/kg/hour (LD50). Rats were divided into 2 groups: amlodipine followed by methylene blue or amlodipine followed by normal saline (NS) with 15 rats in each group. Rats received methylene blue at 2 mg/kg over 5 mins or an equivalent amount of NS in three intervals from the start of the protocol: Minute 5, 30, and 60. The animals were observed for a total of 2 hours after the start of the protocol. Mortality risk and survival time were analyzed using Fisher’s exact test and Kaplan Meier survival analysis with the log rank test. RESULTS Overall, 1/15 (7%) rats in the saline-treated group survived to 120 minutes compared with 5/15 (33%) rats in the methylene blue-treated group (difference −26%, 95% CI –54%, 0.3%). The median survival time for the NS group was 42 min (95% CI, 28.1,55.9) and the methylene blue group was 109 min (95% CI, 93.9,124.1). Heart rate and MAP differences between groups were analyzed until 60 minutes. Heart rate was significantly higher in the methylene blue-treated group starting 25 min after the start of the amlodipine infusion (95% CI, 30–113) that was analyzed until 60 minutes. MAP was significantly higher in the methylene blue-treated group starting 25 min after the amlodipine infusion (95% CI, 2–30) that was analyzed up until 60 minutes. CONCLUSIONS Methylene blue did not result in a significant difference in mortality risk. There was an increase heart rate, MAP and median survival time in the methylene blue group. PMID:25441767

Methylene blue inhibits lumefantrine-resistant Plasmodium berghei.

PubMed

Mwangi, Victor Irungu; Mumo, Ruth Mwende; Kiboi, Daniel Muthui; Omar, Sabah Ahmed; Ng'ang'a, Zipporah Waithera; Ozwara, Hastings Suba

2016-06-30

Chemotherapy still is the most effective way to control malaria, a major public health problem in sub-Saharan Africa. The large-scale use of the combination therapy artemether-lumefantrine for malaria treatment in Africa predisposes lumefantrine to emergence of resistance. There is need to identify drugs that can be used as substitutes to lumefantrine for use in combination therapy. Methylene blue, a synthetic anti-methemoglobinemia drug, has been shown to contain antimalarial properties, making it a candidate for drug repurposing. The present study sought to determine antiplasmodial effects of methylene blue against lumefantrine- and pyrimethamine-resistant strains of P. berghei. Activity of methylene blue was assessed using the classical four-day test on mice infected with lumefantrine-resistant and pyrimethamine-resistant P. berghei. A dose of 45 mg/kg/day was effective for testing ED90. Parasitemia and mice survival was determined. At 45 mg/kg/day, methylene blue sustained significant parasite inhibition, over 99%, for at least 6 days post-treatment against lumefantrine-resistant and pyrimethamine-resistant P. berghei (p = 0.0086 and p = 0.0191, respectively). No serious adverse effects were observed. Our results indicate that methylene blue at a concentration of 45 mg/kg/day confers over 99% inhibition against lumefantrine- and pyrimethamine-resistant P. berghei for six days. This shows the potential use methylene blue in the development of antimalarials against lumefantrine- and pyrimethamine-resistant parasites.

Methylene blue improves mitochondrial respiration and decreases oxidative stress in a substrate-dependent manner in diabetic rat hearts.

PubMed

Duicu, Oana M; Privistirescu, Andreea; Wolf, Adrian; Petruş, Alexandra; Dănilă, Maria D; Raţiu, Corina D; Muntean, Danina M; Sturza, Adrian

2017-11-01

Diabetic cardiomyopathy has been systematically associated with compromised mitochondrial energetics and increased generation of reactive oxygen species (ROS) that underlie its progression to heart failure. Methylene blue is a redox drug with reported protective effects mainly on brain mitochondria. The purpose of the present study was to characterize the effects of acute administration of methylene blue on mitochondrial respiration, H 2 O 2 production, and calcium sensitivity in rat heart mitochondria isolated from healthy and 2 months (streptozotocin-induced) diabetic rats. Mitochondrial respiratory function was assessed by high-resolution respirometry. H 2 O 2 production and calcium retention capacity were measured spectrofluorimetrically. The addition of methylene blue (0.1 μmol·L -1 ) elicited an increase in oxygen consumption of mitochondria energized with complex I and II substrates in both normal and diseased mitochondria. Interestingly, methylene blue elicited a significant increase in H 2 O 2 release in the presence of complex I substrates (glutamate and malate), but had an opposite effect in mitochondria energized with complex II substrate (succinate). No changes in the calcium retention capacity of healthy or diabetic mitochondria were found in the presence of methylene blue. In conclusion, in cardiac mitochondria isolated from diabetic and nondiabetic rat hearts, methylene blue improved respiratory function and elicited a dichotomic, substrate-dependent effect on ROS production.

[Methylene blue in the treatment of vasodilatory shock: a Meta-analysis].

PubMed

Zhang, Xiongfeng; Gao, Yun; Pan, Pengfei; Wang, Yi; Li, Wenzhe; Yu, Xiangyou

2017-11-01

To investigate the clinical efficacy of methylene blue in the treatment of refractory hypotension caused by vascular paralysis during the course of vasodilatory shock. The related articles were searched by retrieving the terms using methylene blue, vascular paralysis, hemodynamics, hypotension, vasodilatory shock in CNKI, China Biomedical Literature database, Wanfang database, PubMed, Springer Link, and BIOSIS Previews database. The retrieval time was from January 1994 to June 2017. The randomized clinical trials (RCTs) which using methylene blue as the experimental group, normal saline or catecholamine as the control in the treatment of refractory hypotension caused by vascular paralysis during the course of vasodilatory shock were collected. The primary end points were mean arterial pressure (MAP) immediately or 1 hour after the methylene blue administration, and the mortality at the longest follow-up available; the secondary end point was serum lactic acid (Lac) 1 hour after the methylene blue administration. Literature screening, data extraction and quality evaluation were carried out by two researchers. Meta analysis was performed using RevMan 5.3 software. The sensitivity analysis was performed in two trials with low risk of bias. The funnel plot for MAP was performed in five relative trials to analyze the research and publication bias. Totally 269 relative articles were collected, according to the inclusion and exclusion criteria, finally 6 RCTs with 214 patients were enrolled, 108 in methylene blue group, and 106 in control group. Four of the studies were considered to have mild to moderate risk of bias, two studies of high risk of bias. The Meta-analysis demonstrated that compared with the control group, methylene blue could significantly improve MAP [mean difference (MD) = 4.87, 95% confidence interval (95%CI) = 2.61 to 7.13, P < 0.000 1], reduce the serum Lac levels (MD = -1.06, 95%CI = -1.98 to -0.14, P = 0.02), and the mortality was decreased without statistical difference [odds ratio (OR) = 0.58, 95%CI = 0.25 to 1.31, P = 0.19]. Sensitivity analysis was performed in two trials with low risk of bias, which demonstrated methylene blue could exactly increase MAP (MD = 8.93, 95%CI = 1.55 to 16.32, P = 0.02). Funnel plot for MAP was performed in five relative trials which found no obvious publication bias. Methylene blue could significantly increase MAP in the patients with refractory hypotension caused by vascular paralysis during the course of vasodilatory shock, decrease the Lac levels, and does not increase the risk of death. Therefore, methylene blue should be a potential and safe vasoconstrictor.

Methylene blue is associated with poor outcomes in vasoplegic shock.

PubMed

Weiner, Menachem M; Lin, Hung-Mo; Danforth, Dennis; Rao, Srikar; Hosseinian, Leila; Fischer, Gregory W

2013-12-01

The purpose of this study was to investigate whether patients who received methylene blue as treatment for vasoplegia during cardiac surgery with cardiopulmonary bypass had decreased morbidity and mortality. Retrospective analysis. Single tertiary care university hospital. Adult patients who suffered from vasoplegia and underwent all types of cardiac surgery with cardiopulmonary bypass at this institution between 2007 and 2008. With IRB approval, the authors reviewed the charts of the identified patients and divided them into 2 groups based on whether they had received methylene blue. Two hundred twenty-six patients were identified who met the inclusion criteria for the study. Fifty-seven of these patients had received methylene blue for vasoplegia. The authors collected data on preoperative and intraoperative variables as well as outcomes. The patients who received methylene blue had higher rates of in-hospital mortality, a compilation of morbidities, as well as renal failure and hyperbilirubinemia. A multiple logistic regression model demonstrated that receiving methylene blue was an independent predictor of in-hospital mortality (p value: 0.007, OR 4.26, 95% CI: 1.49-12.12), compilation of morbidities (p value: 0.001, OR 4.80, 95% CI: 1.85-12.43), and hyperbilirubinemia (p value:<0.001, OR 6.58, 95% CI: 2.91-14.89). Using propensity score matching, the association with morbidity was again seen but the association with mortality was not found. The current study identified the use of methylene blue as treatment for vasoplegia to be independently associated with poor outcomes. While further studies are required, a thorough risk-benefit analysis should be applied before using methylene blue and, perhaps, it should be relegated to rescue use and not as first-line therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

Thrombin generation, ProC(®)Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation.

PubMed

Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E; Greinacher, Andreas; Selleng, Kathleen

2016-01-01

Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.

Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue

NASA Astrophysics Data System (ADS)

Liu, Qing-Song; Zheng, Tong; Li, Nan; Wang, Peng; Abulikemu, Gulizhaer

2010-03-01

Modification of bamboo-based activated carbon was carried out in a microwave oven under N 2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N 2 adsorption, acid-base titration, point of zero charge (pH pzc) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pH pzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons.

Preoperative Localization of Mediastinal Parathyroid Adenoma with Intra-arterial Methylene Blue.

PubMed

Salman, Rida; Sebaaly, Mikhael G; Wehbe, Mohammad Rachad; Sfeir, Pierre; Khalife, Mohamad; Al-Kutoubi, Aghiad

2017-06-01

Ectopic parathyroid is found in 16% of patients with hyperparathyroidism. 2% of ectopic parathyroid adenomas are not accessible to standard cervical excision. In such cases, video-assisted thoracoscopic resection is the recommended definitive treatment. We present a case of mediastinal parathyroid adenoma localized preoperatively by injecting methylene blue within a branch of the internal mammary artery that is supplying the adenoma. Intra-arterial methylene blue injection facilitated visualization and resection of the adenoma. The preoperative intra-arterial infusion of methylene blue appears to be an effective and safe method for localization of ectopic mediastinal parathyroid adenomas and allows rapid identification during thoracoscopic resection.

Preoperative Localization of Mediastinal Parathyroid Adenoma with Intra-arterial Methylene Blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salman, Rida; Sebaaly, Mikhael G.; Wehbe, Mohammad Rachad

Ectopic parathyroid is found in 16% of patients with hyperparathyroidism. 2% of ectopic parathyroid adenomas are not accessible to standard cervical excision. In such cases, video-assisted thoracoscopic resection is the recommended definitive treatment. We present a case of mediastinal parathyroid adenoma localized preoperatively by injecting methylene blue within a branch of the internal mammary artery that is supplying the adenoma. Intra-arterial methylene blue injection facilitated visualization and resection of the adenoma. The preoperative intra-arterial infusion of methylene blue appears to be an effective and safe method for localization of ectopic mediastinal parathyroid adenomas and allows rapid identification during thoracoscopic resection.

FURTHER STUDIES ON THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT, WITH SOME OBSERVATIONS ON METHYLENE BLUE

PubMed Central

Harvey, E. Newton

1926-01-01

1. Eosin, erythrosin, rose bengale, cyanosin, acridine, and methylene blue act photodynamically on the luminescence of a Cypridina luciferin-luciferase solution. In presence of these dyes inhibition of luminescence, which without the dye occurs only in blue-violet light, takes place in green, yellow, orange, or red light, depending on the position of the absorption bands of the dye. 2. Inhibition of Cypridina luminescence without photosensitive dye in blue-violet light, or with photosensitive dye in longer wave-lengths, does not occur in absence of oxygen. Light acts by accelerating the oxidation of luciferin without luminescence. Eosin or methylene blue act by making longer wave-lengths effective, but there is no evidence that these dyes become reduced in the process. 3. The luciferin-oxyluciferin system is similar to the methylene white-methylene blue system in many ways but not exactly similar in respect to photochemical change. Oxidation of the dye is favored in acid solution, reduction in alkaline solution. However, oxidation of luciferin is favored in all pH ranges from 4 to 10 but is much more rapid in alkaline solution, either in light or darkness. There is no evidence that reduction of oxyluciferin is favored in alkaline solution. Clark's observation that oxidation (blueing) of methylene white occurs in complete absence of oxygen has been confirmed for acid solutions. I observed no blueing in light in alkaline solution. PMID:19872301

Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study.

PubMed

Alda, Martin; McKinnon, Margaret; Blagdon, Ryan; Garnham, Julie; MacLellan, Susan; O'Donovan, Claire; Hajek, Tomas; Nair, Cynthia; Dursun, Serdar; MacQueen, Glenda

2017-01-01

Residual symptoms and cognitive impairment are among important sources of disability in patients with bipolar disorder. Methylene blue could improve such symptoms because of its potential neuroprotective effects. We conducted a double-blind crossover study of a low dose (15 mg, 'placebo') and an active dose (195 mg) of methylene blue in patients with bipolar disorder treated with lamotrigine. Thirty-seven participants were enrolled in a 6-month trial (trial registration: NCT00214877). The outcome measures included severity of depression, mania and anxiety, and cognitive functioning. The active dose of methylene blue significantly improved symptoms of depression both on the Montgomery-Åsberg Depression Rating Scale and Hamilton Rating Scale for Depression (P = 0.02 and 0.05 in last-observation-carried-forward analysis). It also reduced the symptoms of anxiety measured by the Hamilton Rating Scale for Anxiety (P = 0.02). The symptoms of mania remained low and stable throughout the study. The effects of methylene blue on cognitive symptoms were not significant. The medication was well tolerated with transient and mild side-effects. Methylene blue used as an adjunctive medication improved residual symptoms of depression and anxiety in patients with bipolar disorder. © The Royal College of Psychiatrists 2017.

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy.

PubMed

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-03-06

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. "Tangle busting" compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 min, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy

PubMed Central

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-01-01

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. “Tangle busting” compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 minutes, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. PMID:24462887

Comparison of methylene blue/gentian violet stain to Gram's stain for the rapid diagnosis of gonococcal urethritis in men.

PubMed

Taylor, Stephanie N; DiCarlo, Richard P; Martin, David H

2011-11-01

We compared a simple, one-step staining procedure using a mixture of methylene blue and gentian violet to Gram stain for the detection of gonococcal urethritis. The sensitivity and specificity of both Gram stain and methylene blue/gentian violet stain were 97.3% and 99.6%, respectively. There was a 100% correlation between the 2 methods.

Quirks of dye nomenclature. 8. Methylene blue, azure and violet.

PubMed

Cooksey, C J

2017-01-01

Methylene blue was synthesized in 1877 and soon found application in medicine, staining for microscopy and as an industrial dye and pigment. An enormous literature has accumulated since its introduction. Early on, it was known that methylene blue could be degraded easily by demethylation; consequently, the purity of commercial samples often was low. Therefore, demethylation products, such as azures and methylene violet, also are considered here. The names and identity of the components, their varying modes of manufacture, analytical methods and their contribution to biological staining are discussed.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of methylene blue active substances by spectrophotometry

USGS Publications Warehouse

Burkhardt, Mark R.; Cinotto, Pete J.; Frahm, Galen W.; Woodworth, Mark T.; Pritt, Jeffrey W.

1995-01-01

A method for the determination of methylene blue active substances in whole-water samples by liquid-liquid extraction and spectrophotometric detection is described. Sulfate and sulfonate-based surfectants are reacted with methylene blue to form a blue-colored complex. The complex is extracted into chloroform, back-washed with an acidified phosphate-based buffer solution, and measured against external standards with a probe spectrophotometer. The method detection limt for routine analysis is 0.02 milligram per liter. The precision is plus/minus 10 percent relative standard deviation. The positive bias from nitrate and chloride and U.S. Geological Survey method O-3111-83 for methylene blue active substances is minized by adding a back-washing step.

Efficacy of methylene blue in an experimental model of calcium channel blocker-induced shock.

PubMed

Jang, David H; Donovan, Sean; Nelson, Lewis S; Bania, Theodore C; Hoffman, Robert S; Chu, Jason

2015-04-01

Calcium channel blocker poisonings account for a substantial number of reported deaths from cardiovascular drugs. Although supportive care is the mainstay of treatment, experimental therapies such as high-dose insulin-euglycemia and lipid emulsion have been studied in animal models and used in humans. In the most severe cases, even aggressive care is inadequate and deaths occur. In both experimental models and clinical cases of vasodilatory shock, methylene blue improves hemodynamic measures. It acts as a nitric oxide scavenger and inhibits guanylate cyclase that is responsible for the production of cyclic guanosine monophosphate (cGMP). Excessive cGMP production is associated with refractory vasodilatory shock in sepsis and anaphylaxis. The aim of this study is to determine the efficacy of methylene blue in an animal model of amlodipine-induced shock. Sprague-Dawley rats were anesthetized, ventilated, and instrumented for continuous blood pressure and pulse rate monitoring. The dose of amlodipine that produced death within 60 minutes was 17 mg/kg per hour (LD50). Rats were divided into 2 groups: amlodipine followed by methylene blue or amlodipine followed by normal saline solution, with 15 rats in each group. Rats received methylene blue at 2 mg/kg during 5 minutes or an equivalent amount of normal saline solution in 3 intervals from the start of the protocol: minutes 5, 30, and 60. The animals were observed for a total of 2 hours after the start of the protocol. Mortality risk and survival time were analyzed with Fisher's exact test and Kaplan-Meier survival analysis with the log rank test. Overall, 1 of 15 rats (7%) in the saline solution-treated group survived to 120 minutes compared with 5 of 15 (33%) in the methylene blue-treated group (difference -26%; 95% confidence interval [CI] -54% to 0.3%). The median survival time for the normal saline solution group was 42 minutes (95% CI 28.1 to 55.9 minutes); for the methylene blue group, 109 minutes (95% CI 93.9 to 124.1 minutes). Pulse rate and mean arterial pressure (MAP) differences between groups were analyzed until 60 minutes. Pulse rate was significantly higher in the methylene blue-treated group beginning 25 minutes after the start of the amlodipine infusion (95% CI 30 to 113 minutes) that was analyzed until 60 minutes. MAP was significantly higher in the methylene blue-treated group starting 25 minutes after the amlodipine infusion (95% CI 2 to 30 minutes) that was analyzed until 60 minutes. Methylene blue did not result in a significant difference in mortality risk. There was an increased pulse rate, MAP, and median survival time in the methylene blue group. Copyright © 2014 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Removal of basic dye (methylene blue) from wastewaters utilizing beer brewery waste.

PubMed

Tsai, Wen-Tien; Hsu, Hsin-Chieh; Su, Ting-Yi; Lin, Keng-Yu; Lin, Chien-Ming

2008-06-15

In the work, the beer brewery waste has been shown to be a low-cost adsorbent for the removal of basic dye from the aqueous solution as compared to its precursor (i.e., diatomite) based on its physical and chemical characterizations including surface area, pore volume, scanning electron microscopy (SEM), and non-mineral elemental analyses. The pore properties of this waste were significantly larger than those of its raw material, reflecting that the trapped organic matrices contained in the waste probably provided additional adsorption sites and/or adsorption area. The results of preliminary adsorption kinetics showed that the diatomite waste could be directly used as a potential adsorbent for removal of methylene blue on the basis of its adsorption-biosorption mechanisms. The adsorption parameters thus obtained from the pseudo-second-order model were in accordance with their pore properties. From the results of adsorption isotherm at 298 K and the applicability examinations in treating industrial wastewater containing basic dye, it was further found that the adsorption capacities of diatomite waste were superior to those of diatomite, which were also in good agreement with their corresponding physical properties. From the results mentioned above, it is feasible to utilize the food-processing waste for removing dye from the industrial dying wastewater.

Phenothiaziniums as putative photobactericidal agents for red blood cell concentrates.

PubMed

Wainwright, M; Phoenix, D A; Smillie, T E; Wareing, D R

2001-10-01

The antibacterial activities of Methylene Blue and several of its congeners were measured against Yersinia enterocolitica, a gram-negative pathogen known to exhibit significant growth at 4 degrees C and thus constituting a threat to red blood cell concentrates which are stored at this temperature. None of the derivatives was highly active in dark conditions, as expected, but on illumination using a lamp emitting light in the waveband 615-645 nm, considerable bactericidal activity was noted using similar photosensitizer concentrations to those used elsewhere to inactivate blood-borne viruses. Two novel compounds in this area, the phenothiazinium New Methylene Blue N and the phenoxazinium Brilliant Cresyl Blue, exhibited bactericidal activity at lower concentrations than both of the established phenothiaziniums, Methylene Blue and Toluidine Blue O and the recently published blood photovirucidal agent 1,9-Dimethyl Methylene Blue. The photoactivity of these compounds was undiminished in the presence of red blood cells.

Methylene Blue as a Diagnostic Aid in the Early Detection of Potentially Malignant and Malignant Lesions of Oral Mucosa.

PubMed

Lejoy, Abraham; Arpita, Rai; Krishna, Burde; Venkatesh, Naikmasur

2016-05-01

In vivo stains are the prompt resources, which have emerged in recent years to aid as clinical diagnostic tools in detecting early potentially malignant and malignant lesions. Toluidine blue, by its property of retaining in the increased DNA and RNA cellular activity areas, aids in delineating the suspicious areas. However, it is hazardous if swallowed, and has been shown to have toxicity to fibroblasts. Methylene blue has a similar chemical structure and exhibits similar physicochemical properties as toluidine blue. It is less toxic to the human body and has recently been proposed for screening some gastrointestinal or prostate tumors. The application of this material in detecting oral lesions has so far not been addressed. The objective of this study was to evaluate the sensitivity and reliability of in vivo staining with methylene blue as a diagnostic adjunct in screening for oral malignant or potentially malignant lesions. The present study involved the examination of 75 patients suspected of having oral malignant or potentially malignant lesions by methylene blue staining. The results of methylene blue uptake were compared with a simultaneous biopsy of these lesions. The overall sensitivity was 95% (100% for malignancy and 92% for potentially malignant lesions) and specificity was 70%. The positive predictive value was 91% and negative predictive value of 80% was observed in the study. We consider that methylene blue staining is a useful diagnostic adjunct in a large, community-based oral cancer screening program for high-risk individuals.

Study of Methylene Blue Ototoxicity in the Guinea Pig.

PubMed

Belhassen, Sarah; Alzahrani, Musaed; Nader, Marc-Elie; Gaboury, Louis; Saliba, Issam

2017-11-01

Methylene blue is widely used in the medical field, especially as a blue dye for staining. It is also used as a photosensitizing agent in antimicrobial photodynamic therapy, which once photoactivated is effective for the eradication of several multi-resistant bacteria. The objective of this study was to investigate the ototoxic potential of methylene blue and precise its use in otology. It was a prospective animal study performed on guinea pigs in our tertiary medical center. We divided the animals into two groups: an experimental group and a control group, who underwent a series of three intratympanic (IT) injections. In the control group (n = 10), they received injections of gentamicin in one ear (positive control) and normal saline in the contralateral ear (negative control). The experimental group (n = 10) received injections of methylene blue in one ear, compared to injections of normal saline in the contralateral ear. We conducted auditory-evoked brainstem response (ABR) before and 1 week after the injection series. Once this is completed, the cochlea was dissected and caspase-3 was analyzed by immunohistochemistry. The mean difference of hearing loss in the methylene blue group compared to normal saline was 1.50 dB, and it was not shown to be statistically significant (P = 0.688). For the positive control group, which received IT injections of gentamicin, the mean threshold of hearing loss difference for all the frequencies combined was 66.25 dB (P < 0.001). Furthermore, uptake of caspase-3 by immunohistochemistry (apoptotic marker) was negative in our group, which received injections of methylene blue. In light of our results, IT injections of methylene blue did not demonstrate an ototoxic potential. We recommend further studies to precise its use in the otologic field.

Study of Methylene Blue Ototoxicity in the Guinea Pig

PubMed Central

Belhassen, Sarah; Alzahrani, Musaed; Nader, Marc-Elie; Gaboury, Louis; Saliba, Issam

2017-01-01

Background Methylene blue is widely used in the medical field, especially as a blue dye for staining. It is also used as a photosensitizing agent in antimicrobial photodynamic therapy, which once photoactivated is effective for the eradication of several multi-resistant bacteria. The objective of this study was to investigate the ototoxic potential of methylene blue and precise its use in otology. Methods It was a prospective animal study performed on guinea pigs in our tertiary medical center. We divided the animals into two groups: an experimental group and a control group, who underwent a series of three intratympanic (IT) injections. In the control group (n = 10), they received injections of gentamicin in one ear (positive control) and normal saline in the contralateral ear (negative control). The experimental group (n = 10) received injections of methylene blue in one ear, compared to injections of normal saline in the contralateral ear. We conducted auditory-evoked brainstem response (ABR) before and 1 week after the injection series. Once this is completed, the cochlea was dissected and caspase-3 was analyzed by immunohistochemistry. Results The mean difference of hearing loss in the methylene blue group compared to normal saline was 1.50 dB, and it was not shown to be statistically significant (P = 0.688). For the positive control group, which received IT injections of gentamicin, the mean threshold of hearing loss difference for all the frequencies combined was 66.25 dB (P < 0.001). Furthermore, uptake of caspase-3 by immunohistochemistry (apoptotic marker) was negative in our group, which received injections of methylene blue. Conclusion In light of our results, IT injections of methylene blue did not demonstrate an ototoxic potential. We recommend further studies to precise its use in the otologic field. PMID:29038666

Preparation of Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) Material and its Application to Electrochemical Degradation of Methylene Blue in Sodium Chloride Solution

NASA Astrophysics Data System (ADS)

Riyanto; Prawidha, A. D.

2018-01-01

Electrochemical degradation of methylene blue using Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) electrode in sodium chloride have been done. The aim of this work was to degradation of methylene blue using Carbon-Chitosan-Polyvinyl Chloride (CC-PVC). Carbon chitosan composite electrode was preparing by Carbon and Chitosan powder and PVC in 4 mL tetrahydrofuran (THF) solvent and swirled flatly to homogeneous followed by drying in an oven at 100 °C for 3 h. The mixture was placed in stainless steel mould and pressed at 10 ton/cm2. Sodium chloride was used electrolyte solution. The effects of the current and electrolysis time were investigated using spectrophotometer UV-Visible. The experimental results showed that the carbon-chitosan composite electrode have higher effect in the electrochemical degradation of methylene blue in sodium chloride. Based on UV-visible spectra analysis shows current and electrolysis time has high effect to degradation of methylene blue in sodium chloride. Chitosan and polyvinyl chloride can strengthen the bond between the carbons so that the material has the high stability and conductivity. As conclusions is Carbon-Chitosan-Polyvinyl Chloride (CC-PVC) electrode have a high electrochemical activity for degradation of methylene blue in sodium chloride.

Methylene Blue Assay for Estimation of Regenerative Re-Epithelialization In Vivo.

PubMed

Milyavsky, Maresha; Dickie, Renee

2017-02-01

The rapidity with which epithelial cells cover a wound surface helps determine whether scarring or scar-less healing results. As methylene blue is a vital dye that is absorbed by damaged tissue but not undamaged epidermis, it can be used to assess wound closure. We sought to develop a quantitative methylene blue exclusion assay to estimate the timeframe for re-epithelialization in regenerating appendages in zebrafish and axolotls, two classic model systems of regeneration. Following application of methylene blue to the amputation plane and extensive washing, the regenerating tail was imaged in vivo until staining was no longer visible. The percent area of the amputation plane positive for methylene blue, representing the area of the amputation plane not yet re-epithelialized, was measured for each time point. The loss of methylene blue occurred rapidly, within ~2.5 h in larval and juvenile axolotls and <1 h in adult zebrafish, consistent with high rates of re-epithelialization in these models of regeneration. The assay allows simple, rapid estimation of the time course for regenerative re-epithelialization without affecting subsequent regenerative ability. This technique will permit comparison of re-epithelialization across different strains and stages, as well as under the influence of various pharmacological inhibitors that affect regeneration.

Rapid alkaline methylene blue supravital staining for assessment of anterior segment infections.

PubMed

Kiuchi, Katsuji

2016-01-01

To present the Löffler's alkaline methylene blue technique of staining eye discharges in eyes with anterior segment infections. The Löffler's alkaline methylene blue staining method is a simple staining technique that can be used to differentiate bacterial, viral, and fungal infections. It is a cationic dye that stains cells blue because the positively charged dye is attracted to negatively charged particles such as polyphosphates, DNAs, and RNAs. Specimens collected from patients by swabbing are smeared onto microscope slides and the methylene blue solution is dropped on the slide. The slide is covered with a glass cover slip and examined under a microscope. The entire time from the collection to the viewing is about 30 seconds. Histopathological images of the conjunctival epithelial cells and neutrophils in eye discharges were dyed blue and the nuclei were stained more intensely blue. Bacterial infections consisted mainly of neutrophils, and viral infections consisted mainly of lymphocytes. Löffler's alkaline methylene blue staining can be done in about 30 seconds for diagnosis. Even though this is a one color stain, it is possible to infer the cause of the infection by detection of the absence of bacteria and/or fungi in context of the differential distribution of neutrophils and lymphocytes.

Alternative mitochondrial electron transfer for the treatment of neurodegenerative diseases and cancers: Methylene blue connects the dots.

PubMed

Yang, Shao-Hua; Li, Wenjun; Sumien, Nathalie; Forster, Michael; Simpkins, James W; Liu, Ran

2017-10-01

Brain has exceptional high requirement for energy metabolism with glucose as the exclusive energy source. Decrease of brain energy metabolism and glucose uptake has been found in patients of Alzheimer's, Parkinson's and other neurodegenerative diseases, providing a clear link between neurodegenerative disorders and energy metabolism. On the other hand, cancers, including glioblastoma, have increased glucose uptake and rely on aerobic glycolysis for energy metabolism. The switch of high efficient oxidative phosphorylation to low efficient aerobic glycolysis pathway (Warburg effect) provides macromolecule for biosynthesis and proliferation. Current research indicates that methylene blue, a century old drug, can receive electron from NADH in the presence of complex I and donates it to cytochrome c, providing an alternative electron transfer pathway. Methylene blue increases oxygen consumption, decrease glycolysis, and increases glucose uptake in vitro. Methylene blue enhances glucose uptake and regional cerebral blood flow in rats upon acute treatment. In addition, methylene blue provides protective effect in neuron and astrocyte against various insults in vitro and in rodent models of Alzheimer's, Parkinson's, and Huntington's disease. In glioblastoma cells, methylene blue reverses Warburg effect by enhancing mitochondrial oxidative phosphorylation, arrests glioma cell cycle at s-phase, and inhibits glioma cell proliferation. Accordingly, methylene blue activates AMP-activated protein kinase, inhibits downstream acetyl-coA carboxylase and cyclin-dependent kinases. In summary, there is accumulating evidence providing a proof of concept that enhancement of mitochondrial oxidative phosphorylation via alternative mitochondrial electron transfer may offer protective action against neurodegenerative diseases and inhibit cancers proliferation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Methylene blue-aided cholangioscopy in patients with biliary strictures: feasibility and outcome analysis.

PubMed

Hoffman, A; Kiesslich, R; Bittinger, F; Galle, P R; Neurath, M F

2008-07-01

Chromoendoscopy using methylene blue is employed in the gastrointestinal tract to delineate neoplastic lesions. We tested the value of chromoendoscopy during choledochoscopy for characterization of local inflammation, neoplasias, and other alterations in patients with biliary strictures. Patients with suspected biliary lesions were scheduled for endoscopic retrograde cholangiography with subsequent cholangioscopy. After initial inspection of the bile duct, 15 ml methylene blue (0.1 %) was administered via the working channel of the cholangioscope. Newly appearing circumscribed or unstained lesions were judged according to their macroscopic type and staining features. Methylene-blue-aided diagnosis was compared with either clinical follow-up of the patients or, in some cases, with the results of targeted biopsies. A total of 55 patients [biliary stenosis/cholestasis of unknown origin (n = 24), stenosis after orthotopic liver transplantation (n = 11), primary sclerosing cholangitis (n = 20)] were included. Methylene blue unmasked subtle mucosal changes and permitted macroscopic characterization of circumscribed lesions. Characteristic surface staining patterns were seen in chronic inflammation, dysplasia, and ischemic-type biliary lesions. Nondysplastic mucosa appeared homogeneously stained, whereas scarred strictures showed a weak uptake of methylene blue. In this prospective feasibility study, methylene-blue-aided cholangioscopy was used for the first time to define different staining patterns of the bile duct. The differences in staining patterns identified normal, dysplastic, and inflamed mucosa of the bile duct, as was proved by follow-up or, in some cases, histology. Whereas homogeneous staining predicted the presence of normal mucosa, absence of staining of circumscribed lesions, or diffused staining of such lesions, represented neoplastic changes or inflammation.

Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain.

PubMed

Rodriguez, Pavel; Zhou, Wei; Barrett, Douglas W; Altmeyer, Wilson; Gutierrez, Juan E; Li, Jinqi; Lancaster, Jack L; Gonzalez-Lima, Francisco; Duong, Timothy Q

2016-11-01

Purpose To investigate the sustained-attention and memory-enhancing neural correlates of the oral administration of methylene blue in the healthy human brain. Materials and Methods The institutional review board approved this prospective, HIPAA-compliant, randomized, double-blinded, placebo-controlled clinical trial, and all patients provided informed consent. Twenty-six subjects (age range, 22-62 years) were enrolled. Functional magnetic resonance (MR) imaging was performed with a psychomotor vigilance task (sustained attention) and delayed match-to-sample tasks (short-term memory) before and 1 hour after administration of low-dose methylene blue or a placebo. Cerebrovascular reactivity effects were also measured with the carbon dioxide challenge, in which a 2 × 2 repeated-measures analysis of variance was performed with a drug (methylene blue vs placebo) and time (before vs after administration of the drug) as factors to assess drug × time between group interactions. Multiple comparison correction was applied, with cluster-corrected P < .05 indicating a significant difference. Results Administration of methylene blue increased response in the bilateral insular cortex during a psychomotor vigilance task (Z = 2.9-3.4, P = .01-.008) and functional MR imaging response during a short-term memory task involving the prefrontal, parietal, and occipital cortex (Z = 2.9-4.2, P = .03-.0003). Methylene blue was also associated with a 7% increase in correct responses during memory retrieval (P = .01). Conclusion Low-dose methylene blue can increase functional MR imaging activity during sustained attention and short-term memory tasks and enhance memory retrieval. © RSNA, 2016 Online supplemental material is available for this article.

A methylene blue-assisted technique for harvesting lymph nodes after radical surgery for gastric cancer: a prospective, randomized, controlled study.

PubMed

Aoyama, Toru; Fujikawa, Hirohito; Cho, Haruhiko; Ogata, Takashi; Shirai, Junya; Hayashi, Tsutomu; Rino, Yasushi; Masuda, Munetaka; Oba, Mari S; Morita, Satoshi; Yoshikawa, Takaki

2015-02-01

Harvesting lymph nodes (LNs) after gastrectomy is essential for accurate staging. This trial evaluated the efficiency and quality of a conventional method and a methylene blue-assisted method in a randomized manner. The key eligibility criteria were as follows: (i) histologically proven adenocarcinoma of the stomach; (ii) clinical stage I-III; (iii) R0 resection planned by gastrectomy with D1+ or D2 lymphadenectomy. The primary endpoint was the ratio of the pathologic number of harvested LNs per time (minutes) as an efficacy measure. The secondary endpoint was the number of harvested LNs, as a quality measure. Between August 2012 and December 2012, 60 patients were assigned to undergo treatment using the conventional method (n=29) and the methylene blue dye method (n=31). The baseline demographics were mostly well balanced between the 2 groups. The number of harvested LNs (mean±SD) was 33.6±11.9 in the conventional arm and 43.4±13.9 in the methylene blue arm (P=0.005). The ratio of the number of the harvested LNs per time was 1.12±0.46 LNs/min in the conventional arm and 1.49±0.59 LNs/min in the methylene blue arm (P=0.010). In the subgroup analyses, the quality and efficacy were both superior for the methylene blue dye method compared with the conventional method. The methylene blue technique is recommended for harvesting LNs during gastric cancer surgery on the basis of both the quality and efficacy.

Microgel-Encapsulated Methylene Blue for the Treatment of Breast Cancer Cells by Photodynamic Therapy

PubMed Central

Khanal, Anil; Bui, Minh-Phuong Ngoc

2014-01-01

Purpose Photodynamic therapy (PDT) is gaining increasing recognition for breast cancer treatment because it offers local selectivity and reduced toxic side effects compared to radiotherapy and chemotherapy. In PDT, photosensitizer drugs are loaded in different nanomaterials and used in combination with light exposure. However, the most representative issue with PDT is the difficulty of nanomaterials to encapsulate anticancer drugs at high doses, which results in low efficacy of the PDT treatment. Here, we proposed the development of the poly(N-isopropylacrylamide) (PNIPAM) microgel for the encapsulation of methylene blue, an anticancer drug, for its use as breast cancer treatment in MCF-7 cell line. Methods We developed biocompatible microgels based on nonfunctionalized PNIPAM and its corresponding anionically functionalized PNIPAM and polyacrylic acid (PNIPAM-co-PAA) microgel. Methylene blue was used as the photosensitizer drug because of its ability to generate toxic reactive oxygen species upon exposure to light at 664 nm. Core PNIPAM and core/shell PNIPAM-co-PAA microgels were synthesized and characterized using ultraviolet-visible spectroscopy and dynamic light scattering. The effect of methylene blue was evaluated using the MCF-7 cell line. Results Loading of methylene blue in core PNIPAM microgel was higher than that in the core/shell PNIPAM-co-PAA microgel, indicating that electrostatic interactions did not play an important role in loading a cationic drug. This behavior is probably due to the skin layer inhibiting the high uptake of drugs in the PNIPAM-co-PAA microgel. Core PNIPAM microgel effectively retained the cationic drug (i.e., methylene blue) for several hours compared to core/shell PNIPAM-co-PAA and enhanced its photodynamic efficacy in vitro more than that of free methylene blue. Conclusion Our results showed that the employment of core PNIPAM and core/shell PNIPAM-co-PAA microgels enhanced the encapsulation of methylene blue. Core PNIPAM microgel released the drug more slowly than did core/shell PNIPAM-co-PAA, and it effectively inhibited the growth of MCF-7 cells. PMID:24744793

Microgel-encapsulated methylene blue for the treatment of breast cancer cells by photodynamic therapy.

PubMed

Khanal, Anil; Bui, Minh-Phuong Ngoc; Seo, Seong S

2014-03-01

Photodynamic therapy (PDT) is gaining increasing recognition for breast cancer treatment because it offers local selectivity and reduced toxic side effects compared to radiotherapy and chemotherapy. In PDT, photosensitizer drugs are loaded in different nanomaterials and used in combination with light exposure. However, the most representative issue with PDT is the difficulty of nanomaterials to encapsulate anticancer drugs at high doses, which results in low efficacy of the PDT treatment. Here, we proposed the development of the poly(N-isopropylacrylamide) (PNIPAM) microgel for the encapsulation of methylene blue, an anticancer drug, for its use as breast cancer treatment in MCF-7 cell line. We developed biocompatible microgels based on nonfunctionalized PNIPAM and its corresponding anionically functionalized PNIPAM and polyacrylic acid (PNIPAM-co-PAA) microgel. Methylene blue was used as the photosensitizer drug because of its ability to generate toxic reactive oxygen species upon exposure to light at 664 nm. Core PNIPAM and core/shell PNIPAM-co-PAA microgels were synthesized and characterized using ultraviolet-visible spectroscopy and dynamic light scattering. The effect of methylene blue was evaluated using the MCF-7 cell line. Loading of methylene blue in core PNIPAM microgel was higher than that in the core/shell PNIPAM-co-PAA microgel, indicating that electrostatic interactions did not play an important role in loading a cationic drug. This behavior is probably due to the skin layer inhibiting the high uptake of drugs in the PNIPAM-co-PAA microgel. Core PNIPAM microgel effectively retained the cationic drug (i.e., methylene blue) for several hours compared to core/shell PNIPAM-co-PAA and enhanced its photodynamic efficacy in vitro more than that of free methylene blue. Our results showed that the employment of core PNIPAM and core/shell PNIPAM-co-PAA microgels enhanced the encapsulation of methylene blue. Core PNIPAM microgel released the drug more slowly than did core/shell PNIPAM-co-PAA, and it effectively inhibited the growth of MCF-7 cells.

Methylene Blue-Guided Debridement as an Intraoperative Adjunct for the Surgical Treatment of Periprosthetic Joint Infection.

PubMed

Shaw, Jeremy D; Miller, Steve; Plourde, Anna; Shaw, Daniel L; Wustrack, Rosanna; Hansen, Erik N

2017-12-01

Current methods to identify infected tissue in periprosthetic joint infection (PJI) are inadequate. The purpose of this study was (1) to assess methylene blue-guided surgical debridement as a novel technique in PJI using quantitative microbiology and (2) to evaluate clinical success based on eradication of infection and infection-free survival. Sixteen total knee arthroplasty patients meeting Musculoskeletal Infection Society criteria for PJI undergoing the first stage of 2-stage exchange arthroplasty were included in this prospective study. Dilute methylene blue (0.1%) was instilled in the knee before debridement, residual dye was removed, and stained tissue was debrided. Paired tissue samples, stained and unstained, were collected from the femur, tibia, and capsule during debridement. Samples were analyzed by neutrophil count, semiquantitative culture, and quantitative polymerase chain reaction (PCR). Clinical success was a secondary outcome. The mean age was 64.0 ± 6.0 years, and follow-up was 24.4 ± 3.5 months. More bacteria were found in methylene blue-stained vs unstained tissue-based on semiquantitative culture (P = .001). PCR for staphylococcal species showed 9-fold greater bioburden in methylene blue-stained vs unstained tissue (P = .02). Tissue pathology found 53 ± 46 polymorphonuclear leukocytes per high-power field in methylene blue-stained vs 4 ± 13 in unstained tissue (P = .0001). All subjects cleared their primary infection and underwent reimplantation. At mean 2-year follow-up, 25% of patients failed secondary to new infection with a different organism. These results suggest a role for methylene blue in providing a visual index of surgical debridement in the treatment of PJI. Copyright © 2017 Elsevier Inc. All rights reserved.

pH influences the biocompatibility of methylene blue solutions.

PubMed

Gusman, David Jonathan Rodrigues; Cintra, Luciano Tavares Angelo; Novaes, Vivian Cristina Noronha; Matheus, Henrique Rinaldi; de Araujo, Nathália Januario; de Almeida, Juliano Milanezi

2018-01-01

The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue. Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)-empty tube, fibrin group (G-F)-tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)-tube filled with fibrin sponge soaked by methylene blue (100 μg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)-tube filled with fibrin sponge and soaked by methylene blue (100 μg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 μm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal-Wallis test (p ≤ 0.05). At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups. Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

Synthesis of mesoporous TiO2-curcumin nanoparticles for photocatalytic degradation of methylene blue dye.

PubMed

Abou-Gamra, Z M; Ahmed, M A

2016-07-01

Herein, we demonstrate a facile route for synthesis a new photocatalyst based on TiO2-curcumin nanoparticles for photodegradation of methylene blue dye under UV and visible light irradiation. The photocatalyst was prepared by sol-gel method using chitosan as biodegradable polymer. The crystalline and the nanostructure were characteristic X-ray diffraction [XRD], adsorption-desorption isotherm and high resolution transmission electron microscopy [HRTEM]. However, the optical features of the samples were investigated by a UV-visible spectrophotometer. It is obvious to notice the removal of the majority of methylene blue dye on a pure titania surface via adsorption mechanism owing to the high surface area and to the organized mesoporous nature of the solid sample. Incorporation of curcumin on titania surface changes the removal direction from adsorption to the photocatalytic pathway. Various photocatalytic experiments were performed to investigate the influence of initial dye concentration, weight of catalyst, stirring and light intensity on the photocatalytic degradation of methylene blue as primary pollutant model. Chemical oxygen demand [COD] test confirms the complete degradation of methylene blue dye. The exceptional photocatalytic reactivity of titania-curcumin nanoparticles is referred to reduction in band gap energy and to the facility of electron transfer from II* curcumin energy level to titania conduction band which increases the concentration of reactive oxygen superoxide radicals which in turn prevents the electron-hole recombination. The effect of various scavengers on the methylene blue dye degradation was investigated using ethanol, ascorbic acid and methyl viologen. The results have pointed out that O2(-) and HO(.) are considered the main active species in the degradation process. A plausible pathway and mechanism for the photocatalytic degradation of methylene blue by titania-curcumin nanoparticles were illustrated. Copyright © 2016 Elsevier B.V. All rights reserved.

Sustained methylene blue staining to guide anatomic hepatectomy for hepatocellular carcinoma: Initial experience and technical details.

PubMed

Shou-wang, Cai; Shi-zhong, Yang; Wen-ping, Lv; Geng, Chen; Wan-qing, Gu; Wei-dong, Duan; Wei-yi, Wang; Zhi-qiang, Huang; Jia-hong, Dong

2015-07-01

The boundary of the target hepatic segment within the liver parenchyma cannot be marked by the use of a conventional anatomic hepatectomy approach. This study describes a novel methylene blue staining technique for guiding the anatomic resection of hepatocellular carcinoma (HCC). Between February 2009 and February 2012, anatomic hepatectomy was performed in 106 patients with HCC via a novel, sustained methylene blue staining technique. Sustained staining was achieved by injecting methylene blue into the distal aspect of the portal vein after exposing Glisson's sheath. The hepatic pedicle was immediately ligated, and the hepatic parenchymal transection was performed along the interface between methylene blue stained tissue and unstained tissue. Anatomic hepatectomies included subsegmentectomy (n = 16), monosegmentectomy (n = 57), multisegmentectomy (n = 27), and hemihepatectomy (n = 6). The portal vein was injected successfully with methylene blue in 100% of cases, and complete staining of the target hepatic segment was achieved in 98 of 106 (92.5%) cases. Mean intraoperative bleeding was 360 ± 90 mL, and the postoperative complication rate was 24.5% (26/106). No perioperative mortality occurred. Operative margins were all negative on pathologic examination. Mean duration of postoperative follow-up was 40 months (range, 24-60). No local recurrence (around the operative margin) occurred. This novel technique of achieving sustained staining by injecting methylene blue then immediately ligating the hepatic pedicle is simple and feasible. It can guide the selection of the operative margin during hepatic parenchyma transection to improve the accuracy of anatomic hepatectomy for the treatment of HCC. Copyright © 2015 Elsevier Inc. All rights reserved.

Multimodal Randomized Functional MR Imaging of the Effects of Methylene Blue in the Human Brain

PubMed Central

Rodriguez, Pavel; Zhou, Wei; Barrett, Douglas W.; Altmeyer, Wilson; Gutierrez, Juan E.; Li, Jinqi; Lancaster, Jack L.; Gonzalez-Lima, Francisco

2016-01-01

Purpose To investigate the sustained-attention and memory-enhancing neural correlates of the oral administration of methylene blue in the healthy human brain. Materials and Methods The institutional review board approved this prospective, HIPAA-compliant, randomized, double-blinded, placebo-controlled clinical trial, and all patients provided informed consent. Twenty-six subjects (age range, 22–62 years) were enrolled. Functional magnetic resonance (MR) imaging was performed with a psychomotor vigilance task (sustained attention) and delayed match-to-sample tasks (short-term memory) before and 1 hour after administration of low-dose methylene blue or a placebo. Cerebrovascular reactivity effects were also measured with the carbon dioxide challenge, in which a 2 × 2 repeated-measures analysis of variance was performed with a drug (methylene blue vs placebo) and time (before vs after administration of the drug) as factors to assess drug × time between group interactions. Multiple comparison correction was applied, with cluster-corrected P < .05 indicating a significant difference. Results Administration of methylene blue increased response in the bilateral insular cortex during a psychomotor vigilance task (Z = 2.9–3.4, P = .01–.008) and functional MR imaging response during a short-term memory task involving the prefrontal, parietal, and occipital cortex (Z = 2.9–4.2, P = .03–.0003). Methylene blue was also associated with a 7% increase in correct responses during memory retrieval (P = .01). Conclusion Low-dose methylene blue can increase functional MR imaging activity during sustained attention and short-term memory tasks and enhance memory retrieval. © RSNA, 2016 Online supplemental material is available for this article. PMID:27351678

A nonradioactive assay for poly(a)-specific ribonuclease activity by methylene blue colorimetry.

PubMed

Cheng, Yuan; Liu, Wei-Feng; Yan, Yong-Bin; Zhou, Hai-Meng

2006-01-01

A simple nonradioactive assay, which was based on the specific shift of the absorbance maximum of methylene blue induced by its intercalation into poly(A) molecules, was developed for poly(A)-specific ribonuclease (PARN). A good linear relationship was found between the absorbance at 662 nm and the poly(A) concentration. The assay conditions, including the concentration of methylene blue, the incubation temperature and time, and the poly(A) concentration were evaluated and optimized.

The antimalarial activities of methylene blue and the 1,4-naphthoquinone 3-[4-(trifluoromethyl)benzyl]-menadione are not due to inhibition of the mitochondrial electron transport chain.

PubMed

Ehrhardt, Katharina; Davioud-Charvet, Elisabeth; Ke, Hangjun; Vaidya, Akhil B; Lanzer, Michael; Deponte, Marcel

2013-05-01

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents in vitro and in vivo. The activity of these structurally diverse compounds against the human malaria parasite Plasmodium falciparum might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are "subversive substrates." These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic P. falciparum cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates.

Treatment of methylene blue containing wastewater by a cost-effective micro-scale biochar/polysulfone mixed matrix hollow fiber membrane: Performance and mechanism studies.

PubMed

He, Jinsong; Cui, Anan; Deng, Shihuai; Chen, J Paul

2018-02-15

Dye containing wastewater has increasingly become an important contamination due to operation of various industries such as textile industry. In this study, a micro-scale biochar particles/polysulfone mixed matrix hollow fiber membrane (MMM) was applied for the removal of methylene blue from water. The static and dynamic adsorption performance was investigated. We found that the MMM exhibited a high removal efficiency of methylene blue under a wide pH range of 4-10. The adsorption process on biochar and MMM obeyed the intraparticle surface diffusion model and Langmuir isotherm model. At neutral pH, the maximum adsorption capacity was 544.459 mg/g for biochar and 165.808 mg/g for MMM. Better regeneration with a desorption rate above 92% was achieved by 1-M NaCl in 90% ethanol aqueous solution. Furthermore, the MMM displayed good performance in treating methylene blue containing wastewater through a continuous filtration mode. More importantly, the MMM showed an excellent reusability for methylene blue removal; it was able to achieve 81% of the permeate yield of the fresh MMM after three regeneration cycles. Finally, the adsorption mechanism studies indicated that the removal of methylene blue was associated with electrostatic interaction, hydrogen bonding and hydrophobic interaction. Copyright © 2017 Elsevier Inc. All rights reserved.

Accuracy of methemoglobin measurements: comparison of six different commercial devices and one manual method.

PubMed

Dötsch, J; Demirakça, S; Hahn, D; Katz, N; Kühl, P G; Rascher, W

1999-06-01

During nitric oxide inhalation, methemoglobinemia needs to be monitored. We compared six commercially available instruments and one manual method for methemoglobin measurements. In addition, we studied whether and to what degree methylene blue interferes with methemoglobin measurements. In vitro methodologic study. Research laboratory in a university hospital. Five healthy volunteers from whom red blood cells were obtained. Methemoglobinemia was generated in a red blood cell suspension by nitric oxide; methemoglobin was measured with six commercial instruments and one manual photometric method to calculate variation coefficients and to determine the differences between the devices. Methemoglobin was measured with and without the addition of methylene blue with two instruments. Measurements were performed immediately after the addition of methylene blue. All six commercially available instruments had variation coefficients of <0.1 at methemoglobin concentrations of 5%, whereas the manual photometric method did not reach a variation coefficient of <0.1 at 8% of methemoglobin. Apart from two devices that measured slightly but significantly higher methemoglobin levels, all instruments measured similar values of methemoglobin when the same samples were determined simultaneously. Higher concentrations of methylene blue (10, 40, 100 microM) reduced substantially the apparent concentrations of methemoglobin. Interference by methylene blue was most pronounced at low methemoglobin levels. With some limitations, all commercial instruments that were tested performed adequately for the monitoring of methemoglobinemia. Methylene blue interferes with the methemoglobin measurements in a dose-dependent manner.

Guided surgical debridement: staining tissues with methylene blue.

PubMed

Dorafshar, Amir H; Gitman, Marina; Henry, Ginard; Agarwal, Shailesh; Gottlieb, Lawrence J

2010-01-01

Precise surgical debridement of wounds is required to achieve wound closure. The authors describe their experience with a technique using topical methylene blue to facilitate precise surgical debridement. In this technique, methylene blue dye is applied topically to the wound surface at the onset of surgery. The stained wound site is then wiped to remove dye from the surface of normal epithelium; eschar, nonviable tissue, and granulation tissue remain stained. The methylene blue-stained tissue is surgically removed, and the newly debrided surface of the wound is assessed for adequate vascularity and biopsied to verify presence of bacteriologic balance before closure. The authors have used this technique in more than 200 wound debridements during the past year, including acute surgical or traumatic wounds, acute and subacute burn wounds, chronic granulating wounds, partially epithelialized wounds, sinus tracts, and fistulae. No adverse reactions have been noted, even on patients undergoing multiple applications through serial operations. Topical application of methylene blue to wounds with mixed tissue content helps to distinguish between viable and nonviable tissue and between epithelialized and nonepithelialized areas, facilitating more precise and complete wound debridement.

Resistance of human butyrylcholinesterase to methylene blue-catalyzed photoinactivation; mass spectrometry analysis of oxidation products.

PubMed

Tacal, Ozden; Li, Bin; Lockridge, Oksana; Schopfer, Lawrence M

2013-01-01

Methylene blue, 3, 7-bis(dimethylamino)-phenothiazin-5-ium chloride, is a reversible inhibitor of human butyrylcholinesterase (BChE) in the absence of light. In the presence of light and oxygen, methylene blue promotes irreversible inhibition of human BChE as a function of time, requiring 3 h irradiation to inhibit 95% activity. Inactivation was accompanied by a progressive loss of Coomassie-stained protein bands on native and denaturing polyacrylamide gels, suggesting backbone fragmentation. Aggregation was not detected. MALDI-TOF/TOF mass spectrometry identified oxidized tryptophan (W52, 56, 231, 376, 412, 490, 522), oxidized methionine (M81, 144, 302, 532, 554, 555), oxidized histidine (H214), oxidized proline (P230), oxidized cysteine (C519) and oxidized serine (S215). A 20 min irradiation in the presence of methylene blue resulted in 17% loss of BChE activity, suggesting that BChE is relatively resistant to methylene blue-catalyzed photoinactivation and that therefore this process could be used to sterilize BChE preparations. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Removal efficiency of methylene blue using activated carbon from waste banana stem: Study on pH influence

NASA Astrophysics Data System (ADS)

Misran, E.; Bani, O.; Situmeang, E. M.; Purba, A. S.

2018-02-01

The effort to remove methylene blue in artificial solution had been conducted using adsorption process. The abundant banana stem waste was utilized as activated carbon precursor. This study aimed to analyse the influence of solution pH to removal efficiency of methylene blue using activated carbon from banana stem as adsorbent. Activated carbon from banana stem was obtained by chemical activation using H3PO4 solution. Proximate analysis result showed that the activated carbon has 47.22% of fixed carbon. This value exhibited that banana stem was a potential adsorbent precursor. Methylene blue solutions were prepared at initial concentration of 50 ppm. The influence of solution pH was investigated with the use of 0.2 g adsorbent for 100 mL dye solution. The adsorption was conducted using shaker with at a constant rate of 100 rpm at room temperature for 90 minutes. The results showed that solution pH influenced the adsorption. The activated carbon from banana stem demonstrated satisfying performance since removal efficiencies of methylene blue were higher than 99%.

Use of methylene blue in the prevention of recurrent intra-abdominal postoperative adhesions.

PubMed

Neagoe, Octavian C; Ionica, Mihaela; Mazilu, Octavian

2018-01-01

Objective To evaluate the efficacy of methylene blue in preventing recurrent symptomatic postoperative adhesions. Methods Patients with a history of >2 surgeries for intra-abdominal adhesion-related complications were selected for this study. Adhesiolysis surgery was subsequently performed using administration of 1% methylene blue. The follow-up period was 28.5 ± 11.1 months. Results Data were available from 20 patients (seven men and 13 women) whose mean ± SD age was 51.2 ± 11.4 years. Adhesions took longer to become symptomatic after the first abdominal surgery when the initial pathology was malignant compared with benign. However, the recurrence of adhesions after a previous adhesiolysis surgery had a similar time onset regardless of the initial disease. Following adhesiolysis surgery with methylene blue, the majority of patients did not present with symptoms associated with adhesion complications (i.e., chronic abdominal pain, bowel obstruction) for the length of the follow-up period. Conclusions The use of methylene blue during adhesiolysis surgery appears to reduce the recurrence of adhesion-related symptoms, suggesting a beneficial effect in the prevention of adhesion formation.

Histological Features of Methylene Blue-Induced Phototoxicity Administered in the Context of Parathyroid Surgery.

PubMed

Maguire, Ciara A; Sharma, Anup; Alarcon, Lida; Ffolkes, Lorrette; Kurzepa, Malgorzata; Ostlere, Lucy; Samarasinghe, Venura; Singh, Manuraj

2017-08-01

Methylene blue is a chromophore dye known for its photosensitizing properties. It is also administered intravenously as a tracer in parathyroid surgery to identify abnormal glands. We describe 2 cases of acute methylene blue-induced phototoxicity in patients who underwent parathyroidectomy. Both patients developed an acute vesiculopustular inflammatory rash on the anterior neck corresponding to the site exposed intraoperatively to overhanging surgical lights. One of the patients also developed a bulla on her finger at the site of attachment of the oxygen probe. Biopsies were taken from both patients at different time points. The histological findings included destruction of sebaceous glands and deposition of diastase-periodic acid-Schiff-positive hyaline material around dermal blood vessels. These features are similar to those seen in skin treated with photodynamic therapy and systemic photosensitivity disorders such as the porphyrias. The wavelengths of light emitted by the surgical lights and oxygen probe overlap with the absorption spectrum of methylene blue. This resulted in excitation of the systemically administered methylene blue at exposed sites, with resultant local tissue damage and a phototoxic reaction.

The photokilling of bladder carcinoma cells in vitro by phenothiazine dyes.

PubMed

Fowler, G J; Rees, R C; Devonshire, R

1990-09-01

The potential photodynamic therapy photosensitizers Methylene Blue, Azure C, Methylene Violet, Thionine, Methylene Green, Haematoporphyrin, Nile Blue A, chloroaluminium phthalocyanine and bis-aluminium phthalocyanine were examined for their photoeffects and dark toxicity against a human superficial bladder carcinoma cell-line. By examination of [3H]thymidine uptake into dye-treated cells after irradiation with a copper-vapour pumped dye laser, it was found that Methylene Blue was the most phototoxic and dark toxic of all the dyes tested, suggesting that the dye might be of some use as a topically applied photodrug for use in photodynamic therapy of superficial or early-recurring carcinomas.

Design and synthesis of metal complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide and their photocatalytic degradation of methylene blue.

PubMed

Krishna, P Murali; Reddy, N B Gopal; Kottam, Nagaraju; Yallur, B C; Katreddi, Hussain Reddy

2013-01-01

The photocatalytic degradation has been considered to be an efficient process for the degradation of organic pollutants, which are present in the effluents released by industries. The photocatalytic bleaching of cationic dye methylene blue was carried out spectrometrically on irradiation of UV light using Cu(II), Ni(II), and Co(II) complexes of (2E)-2-[(2E)-3-phenylprop-2-en-1-ylidene]hydrazinecarbothioamide (HL). The effects of pH and metal ion were studied on the efficiency of the reaction. Cu(II) complex shows better catalytic activity and the highest percentage degradation (~88.8%) of methylene blue was observed at pH 12. A tentative mechanism has also been proposed for the photocatalytic degradation of methylene blue.

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection.

PubMed

Yun, Kangsun

2017-10-12

Urinary tract junction obstruction defects are congenital anomalies inducing hydronephrosis and hydroureter. Murine urinary tract junction obstruction defects can be assessed by tracking methylene blue dye flow within the urinary system. Methylene blue dye is injected into the renal pelvis of perinatal embryonic kidneys and dye flow is monitored from the renal pelvis of the kidney through the ureter and into the bladder lumen after applying hydrostatic pressure. Dye accumulation will be evident in the bladder lumen of the normal perinatal urinary tract, but will be constrained between the renal pelvis and the end point of an abnormal ureter, if urinary tract obstructions occur. This method facilitates the confirmation of urinary tract junction obstructions and visualization of hydronephrosis and hydroureter. This manuscript describes a protocol for methylene blue dye injection into the renal pelvis to confirm urinary tract junction obstructions.

In Vitro Antimicrobial Photodynamic Therapy Against Trichophyton mentagrophytes Using New Methylene Blue as the Photosensitizer.

PubMed

López-Chicón, P; Gulías, Ò; Nonell, S; Agut, M

2016-11-01

Antimicrobial photodynamic therapy combines the use of a photosensitizing drug with light and oxygen to eradicate pathogens. Trichophyton mentagrophytes is a dermatophytic fungus able to invade the skin and keratinized tissues. We have investigated the use of new methylene blue as the photosensitizing agent for antimicrobial photodynamic therapy to produce the in vitro inactivation of T mentagrophytes. A full factorial design was employed to optimize the parameters for photoinactivation of the dermatophyte. The parameters studied were new methylene blue concentration, contact time between the photosensitizing agent and the fungus prior to light treatment, and the fluence of red light (wavelength, 620-645nm) applied. The minimum concentration of new methylene blue necessary to induce the death of all T. mentagrophytes cells in the initial suspension (approximate concentration, 10 6 colony forming units per milliliter) was 50μM for a fluence of 81J/cm 2 after a contact time of 10minutes with the photosensitizing-agent. Increasing the concentration to 100μM allowed the fluence to be decreased to 9J/cm 2 . Comparison of our data with other published data shows that the susceptibility of T. mentagrophytes to antimicrobial photodynamic therapy with new methylene blue is strain-dependent. New methylene blue is a photosensitizing agent that should be considered for the treatment of fungal skin infections caused by this dermatophyte. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Dissimilarities between methylene blue and cyanide on relaxation and cyclic GMP formation in endothelium-intact intrapulmonary artery caused by nitrogen oxide-containing vasodilators and acetylcholine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ignarro, L.J.; Harbison, R.G.; Wood, K.S.

1986-01-01

The objective of the present study was to ascertain whether cyanide shares the properties of methylene blue as a selective inhibitor of vascular smooth muscle relaxation elicited by agents that stimulate the formation of cyclic GMP. Experiments were performed with endothelium-intact rings prepared from bovine intrapulmonary artery. Methylene blue, a good inhibitor of soluble guanylate cyclase, antagonized both arterial relaxation and cyclic GMP accumulation in response to sodium nitroprusside, glyceryl trinitrate, S-nitroso-N-acetylpenicillamine and acetylcholine. In contrast, cyanide inhibited only the responses to sodium nitroprusside. Increasing concentrations of methylene blue depressed resting arterial levels of cyclic GMP and caused slowly developingmore » but marked contractions whereas cyanide was without effect. Contractile responses to phenylephrine, potassium and U46619 were potentiated by methylene blue but not by cyanide. Preincubation of dilute solutions of cyanide containing sodium nitroprusside in oxygenated Krebs' buffer at 37 degrees C for 15 min before addition to bath chambers depressed relaxation and cyclic GMP accumulation caused by sodium nitroprusside markedly. Similar treatment of glyceryl trinitrate, however, failed to alter its effects in arterial rings. A chemical inactivation of sodium nitroprusside by cyanide appears to account for the specific inhibitory action of cyanide on arterial responses to sodium nitroprusside. This study indicates clearly that cyanide does not share the properties of methylene blue as an inhibitor of arterial relaxation elicited by vasodilators that stimulate cyclic GMP formation.« less

The Antimalarial Activities of Methylene Blue and the 1,4-Naphthoquinone 3-[4-(Trifluoromethyl)Benzyl]-Menadione Are Not Due to Inhibition of the Mitochondrial Electron Transport Chain

PubMed Central

Ehrhardt, Katharina; Ke, Hangjun; Vaidya, Akhil B.; Lanzer, Michael

2013-01-01

Methylene blue and a series of recently developed 1,4-naphthoquinones, including 3-[4-(substituted)benzyl]-menadiones, are potent antimalarial agents in vitro and in vivo. The activity of these structurally diverse compounds against the human malaria parasite Plasmodium falciparum might involve their peculiar redox properties. According to the current theory, redox-active methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione are “subversive substrates.” These agents are thought to shuttle electrons from reduced flavoproteins to acceptors such as hemoglobin-associated or free Fe(III)-protoporphyrin IX. The reduction of Fe(III)-protoporphyrin IX could subsequently prevent essential hemoglobin digestion and heme detoxification in the parasite. Alternatively, owing to their structures and redox properties, methylene blue and 1,4-naphthoquinones might also affect the mitochondrial electron transport chain. Here, we tested the latter hypothesis using an established system of transgenic P. falciparum cell lines and the antimalarial agents atovaquone and chloroquine as controls. In contrast to atovaquone, methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione do not inhibit the mitochondrial electron transport chain. A systematic comparison of the morphologies of drug-treated parasites furthermore suggests that the three drugs do not share a mechanism of action. Our findings support the idea that methylene blue and 3-[4-(trifluoromethyl)benzyl]-menadione exert their antimalarial activity as redox-active subversive substrates. PMID:23439633

Methylene blue-related corneal edema and iris discoloration.

PubMed

Timucin, Ozgur Bulent; Karadag, Mehmet Fatih; Aslanci, Mehmet Emin; Baykara, Mehmet

2016-04-01

We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

Macroscopic and pathological assessment of methylene blue and normal saline on postoperative adhesion formation in a rat cecum model.

PubMed

Panahi, Farzad; Sadraie, Seyed Homayoon; Khoshmohabat, Hadi; Shahram, Elias; Kaka, Gholamreza; Hosseinalipour, Mohammad

2012-01-01

Adhesion formation after abdominal surgery is a major cause of postoperative bowel obstruction, infertility, and chronic abdominal pain. In this study, we evaluated the effect of normal saline and methylene blue (MB) on postoperative adhesion formation in a rat cecum model. A total of 30 Wistar female rats in 2 treatment and 1 control groups underwent midline laparotomy and standardized abrasion of the visceral peritoneum. Normal saline and methylene blue were administrated intraperitoneally at the end of the surgical procedure in 2 treatment groups. Fourteen days after surgery, a re-laparotomy was performed for macroscopic and pathological assessment. The adhesion grade and extent of the normal saline group was lower than control and MB groups in macroscopic assessment (P<0.05 for both). A comparison of adhesion stages in pathological assessment showed increment in abdominal adhesion by usage methylene blue 1% and demonstrated significant difference between MB and 2 other groups (P<0.05). Administrated normal saline individually reduce the adhesion grade near cecum. Conversely, usage of methylene blue 1% may unpredictably increase risk of adhesion formation. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Recognition of sentinel lymph nodes in patients with papillary thyroid cancer by nano-carbon and methylene blue.

PubMed

Liu, Fangzhou; Zhu, Yan; Qian, Yichuan; Zhang, Jia; Zhang, Yu; Zhang, Yuan

2017-01-01

To compare the accuracy and feasibility of methylene blue and nano-carbon in clinical tracing of sentinel lymph nodes (SLNs) in patients with papillary thyroid cancer (PTC). Ninety-six PTC patients were selected and randomly divided into a methylene blue group and a nano-carbon group (n=48). During surgery, tracer agent was injected around the tumor, and SLNs were resected and subjected to frozen pathological examination. The results were compared with those of routine pathological examination after surgery. Latent lymph node metastasis (level VI and lateral neck) was detected in both groups, with neck distribution of SLNs. There was no significant difference in the detection rate or accuracy of SLNs between two groups (P>0.05). The incorrect resection rate of parathyroid gland and incidence of temporary hypoparathyroidism in the methylene blue group were significantly higher than those of the nano-carbon group (t=4.137, P<0.05). The state of PTC lymph nodes can be well evaluated by SLN biopsy using both methylene blue and nano-carbon as tracers, but using nano-carbon has a lower incidence rate of parathyroid injury, with great clinical prospects accordingly.

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF

PubMed Central

Ravenna, F.; Feo, C.; Calia, N.; Avoscan, C.; Barbetta, C.; Cavallesco, G. N.

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain. PMID:23091498

Retrograde Instillation of Methylene Blue in the Difficult Diagnosis of BPF.

PubMed

Ravenna, F; Feo, C; Calia, N; Avoscan, C; Barbetta, C; Cavallesco, G N

2012-01-01

We report two cases in which we were able to diagnose bronchopleural fistula through retrograde methylene blue instillation during bronchoscopy. In the first case, methylene blue was injected through an abdominal drain, followed by air instillation and detected in the left bronchial tree, demonstrating the presence of a fistula in the lingula's bronchus. In the second case, methylene blue was injected into a pleural drain, through a breach on a surgical suture and detected in the right bronchial tree, demonstrating the presence of a fistula in the right inferior bronchus. The retrograde instillation of methylene blue, through a drain in the abdomen or the thoracic wall, is a safe, cheap, and practical method that allows the bronchoscopist to identify the presence of a fistula and, more importantly, to identify the exact point on the bronchial tree where a fistula is located. This provides the possibility of sealing the fistula with a variety of devices. It is our opinion that this procedure should be considered a primary method of diagnosis when a bronchopleural fistula is suspected and a drain on the thoracic or abdominal wall is positioned such that effusions are able to drain.

Oxygen sensitive paper

NASA Technical Reports Server (NTRS)

Whidby, J. F.

1973-01-01

Paper is impregnated with mixture of methylene blue and ethylenediaminetetraacetic acid. Methylene blue is photo-reduced to leuco-form. Paper is kept isolated from oxygen until ready for use. Paper can be reused by photo-reduction after oxygen exposure.

Methylene blue test

MedlinePlus

The methylene blue test is a test to determine the type or to treat methemoglobinemia , a blood disorder. ... higher, you can become sick because the protein is not carrying ... of red. Methemoglobinemia has several causes, many of which are ...

The monoamine oxidase inhibition properties of selected structural analogues of methylene blue.

PubMed

Delport, Anzelle; Harvey, Brian H; Petzer, Anél; Petzer, Jacobus P

2017-06-15

The thionine dye, methylene blue (MB), is a potent inhibitor of monoamine oxidase (MAO) A, a property that may, at least in part, mediate its antidepressant effects in humans and animals. The central inhibition of MAO-A by MB has also been linked to serotonin toxicity (ST) which may arise when MB is used in combination with serotonergic drugs. Structural analogues and the principal metabolite of MB, azure B, have also been reported to inhibit the MAO enzymes, with all compounds exhibiting specificity for the MAO-A isoform. To expand on the structure-activity relationships (SARs) of MAO inhibition by MB analogues, the present study investigates the human MAO inhibition properties of five MB analogues: neutral red, Nile blue, new methylene blue, cresyl violet and 1,9-dimethyl methylene blue. Similar to MB, these analogues also are specific MAO-A inhibitors with cresyl violet (IC 50 =0.0037μM), Nile blue (IC 50 =0.0077μM) and 1,9-dimethyl methylene blue (IC 50 =0.018μM) exhibiting higher potency inhibition compared to MB (IC 50 =0.07μM). Nile blue also represents a potent MAO-B inhibitor with an IC 50 value of 0.012μM. From the results it may be concluded that non-thionine MB analogues (e.g. cresyl violet and Nile blue) also may exhibit potent MAO inhibition, a property which should be considered when using these compounds in pharmacological studies. Benzophenoxazines such as cresyl violet and Nile blue are, similar to phenothiazines (e.g. MB), representative of high potency MAO-A inhibitors with a potential risk of ST. Copyright © 2017 Elsevier Inc. All rights reserved.

Photodynamic Therapy With Methylene Blue for Skin Ulcers Infected With Pseudomonas aeruginosa and Fusarium spp.

PubMed

Aspiroz, C; Sevil, M; Toyas, C; Gilaberte, Y

Photodynamic therapy (PDT) is a therapeutic modality with significant antimicrobial activity. We present 2 cases of chronic lower limb ulcers in which fungal and bacterial superinfection complicated management. PDT with methylene blue as the photosensitizer led to clinical and microbiological cure with no significant adverse effects. PDT with methylene blue is a valid option for the management of superinfected chronic ulcers, reducing the use of antibiotics and the induction of resistance. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

[Localizating and Extracting Small Peripheral Nodules of Lung with Simulating 
Radiaotherapy Combining Methylene Blue Staining].

PubMed

Mao, Feng; Zhang, Liang; Gu, Hengle; Zhang, Hui; Lv, Changxing; Shen-Tu, Yang

2016-09-20

With the extensively application of HRCT (high resolution CT) and the popularization of early lung cancer screening, the proportion of small nodullar lung cancer to be operated increases rapidly. Identifying the focus lesions quickly and accurately in operation has shown to be a challenge. We carried out this research trying to make use of and evaluate a new method that localizaes and extracts small peripheral pulmonary nodules by way of simulating radiaotherapy combining methylene blue staining. From February 2012 to January 2015, 97 patients with 100 peripheral pulmonary nodules ≤10 mm in size were simulated puncturing using a radiotherapy planning. When the anaesthesia came into use, methylene blue dye was injected to the virtually identified point corresponding to the surface point, according to the angle and depth previously computed by the radiotherapy planning. The video-assisted thoracoscopic surgery (VATS) wedge resections of the marked lesions were undertaken and the specimens were sent for frozen pathologic examination. The interval time from anesthesia-completing to puncture and injection, The interval time from methylene blue injection to identifying the stained area and the distances between the centre point of the stains and edge of coloured lesion were recorded. Our preoperative localization procedure was successful in 96 of 100 (96%) nodules. The interval time from anesthesia-completing to puncture and injection of methylene blue were (4.85±1.25) min. The interval time from methylene blue injection to identifying the stained area was (16.36±2.36) min. The distances between the centre point of the stains and edge of coloured lesion were (4.78±2.51) mm. No complication was observed in all participants. The new method of locating peripheral pulmonary nodules by simulating simulating radiaotherapy combining methylene blue staining has a high success rate and no complication for localizing small peripheral pulmonary lesions, avoiding the fear and pain of the patients untaken puncture without anaesthesia reducing radial damage.

Silica adsorbent prepared from spent diatomaceous earth and its application to removal of dye from aqueous solution.

PubMed

Tsai, W T; Hsien, K J; Yang, J M

2004-07-15

The objective of this work is to study the activation regeneration of spent diatomaceous earth (SDE) for the preparation of silica adsorbents using thermal regeneration and acid/alkaline activation methods. Under the experimental conditions investigated, it was found that the alkaline activation method carried out by sodium hydroxide under controlled conditions is significantly superior to other heat and activation methods. The porosities of solids thus obtained are over 0.2, indicating that they are basically mesoporous. The optimal porous material thus prepared was used as a mineral adsorbent for methylene blue at 25 degrees C. The adsorption equilibrium revealed that the silica adsorbent can take up over 50 mg/g at relatively low concentrations in aqueous medium from the fittings of Langmuir and Freundlich isotherms with high correlations. On the other hand, the adsorption kinetic of methylene blue under various adsorbent dosages can be well described with a pseudo-second-order reaction model. Copyright 2004 Elsevier Inc.

Potential adsorption of methylene blue from aqueous solution using green macroalgaePosidonia oceanica.

NASA Astrophysics Data System (ADS)

Allouche, F.-N.; Yassaa, N.

2018-03-01

The use of inexpensive biological materials, such as marine algae for removing dyes from contaminated industrial effluents appears as a potential alternative method. The aim of this study is to investigate the aptitude of marine macroalgae Posidonia Oceanica local biomass abundant on the coasts of Algeria for selective sorption of methylene blue (MB) from an aqueous solution in batch experiments at 20 °C. A maximum percentage removal of Posidonia oceanica occurs at pH 5. Equilibrium isotherm data were analyzed using the Langmuir and the Freundlich isotherms. The adsorption equilibrium of methylene blue was best describe by Langmuir model than the Freundlich model. The maximum sorption capacity was 357 mgg-1at pH 5. The sorption data were very well described by the pseudo-second-order model. Keywords: Posidonia oceanica, Methylene blue (MB), Biosorption, Isotherm Equilibrium, Kinetics; Modelling.

Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging

NASA Astrophysics Data System (ADS)

Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L.; Leung, Ben Y. C.; Goertz, David E.; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F.; Kim, Chulhong

2014-01-01

Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging.

PubMed

Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L; Leung, Ben Y C; Goertz, David E; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F; Kim, Chulhong

2014-01-01

Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

A Methylene Blue–assisted Technique for Harvesting Lymph Nodes After Radical Surgery for Gastric Cancer

PubMed Central

Aoyama, Toru; Fujikawa, Hirohito; Cho, Haruhiko; Ogata, Takashi; Shirai, Junya; Hayashi, Tsutomu; Rino, Yasushi; Masuda, Munetaka; Oba, Mari S.; Morita, Satoshi

2015-01-01

Harvesting lymph nodes (LNs) after gastrectomy is essential for accurate staging. This trial evaluated the efficiency and quality of a conventional method and a methylene blue–assisted method in a randomized manner. The key eligibility criteria were as follows: (i) histologically proven adenocarcinoma of the stomach; (ii) clinical stage I-III; (iii) R0 resection planned by gastrectomy with D1+ or D2 lymphadenectomy. The primary endpoint was the ratio of the pathologic number of harvested LNs per time (minutes) as an efficacy measure. The secondary endpoint was the number of harvested LNs, as a quality measure. Between August 2012 and December 2012, 60 patients were assigned to undergo treatment using the conventional method (n=29) and the methylene blue dye method (n=31). The baseline demographics were mostly well balanced between the 2 groups. The number of harvested LNs (mean±SD) was 33.6±11.9 in the conventional arm and 43.4±13.9 in the methylene blue arm (P=0.005). The ratio of the number of the harvested LNs per time was 1.12±0.46 LNs/min in the conventional arm and 1.49±0.59 LNs/min in the methylene blue arm (P=0.010). In the subgroup analyses, the quality and efficacy were both superior for the methylene blue dye method compared with the conventional method. The methylene blue technique is recommended for harvesting LNs during gastric cancer surgery on the basis of both the quality and efficacy. PMID:25356528

Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue.

PubMed

Bradberry, Sally M

2003-01-01

Methaemoglobin is formed by oxidation of ferrous (FeII) haem to the ferric (FeIII) state and the mechanisms by which this occurs are complex. Most cases are due to one of three processes. Firstly, direct oxidation of ferrohaemoglobin, which involves the transfer of electrons from ferrous haem to the oxidising compound. This mechanism proceeds most readily in the absence of oxygen. Secondly, indirect oxidation, a process of co-oxidation which requires haemoglobin-bound oxygen and is involved, for example, in nitrite-induced methaemoglobinaemia. Thirdly, biotransformation of a chemical to an active intermediate that initiates methaemoglobin formation by a variety of mechanisms. This is the means by which most aromatic compounds, such as amino- and nitro-derivatives of benzene, produce methaemoglobin. Methaemoglobinaemia is an uncommon occupational occurrence. Aromatic compounds are responsible for most cases, their lipophilic nature and volatility facilitating absorption during dermal and inhalational exposure, the principal routes implicated in the workplace. Methaemoglobinaemia presents clinically with symptoms and signs of tissue hypoxia. Concentrations around 80% are life-threatening. Features of toxicity may develop over hours or even days when exposure, whether by inhalation or repeated skin contact, is to relatively low concentrations of inducing chemical(s). Not all features observed in patients with methaemoglobinaemia are due to methaemoglobin formation. For example, the intravascular haemolysis caused by oxidising chemicals such as chlorates poses more risk to life than the methaemoglobinaemia that such chemicals induce. If an occupational history is taken, the diagnosis of methaemoglobinaemia should be relatively straightforward. In addition, two clinical observations may help: firstly, the victim is often less unwell than one would expect from the severity of 'cyanosis' and, secondly, the 'cyanosis' is unresponsive to oxygen therapy. Pulse oximetry is unreliable in the presence of methaemoglobinaemia. Arterial blood gas analysis is mandatory in severe poisoning and reveals normal partial pressures of oxygen (pO2) and carbon dioxide (pCO2,), a normal 'calculated' haemoglobin oxygen saturation, an increased methaemoglobin concentration and possibly a metabolic acidosis. Following decontamination, high-flow oxygen should be given to maximise oxygen carriage by remaining ferrous haem. No controlled trial of the efficacy of methylene blue has been performed but clinical experience suggests that methylene blue can increase the rate of methaemoglobin conversion to haemoglobin some 6-fold. Patients with features and/or methaemoglobin concentrations of 30-50%, should be administered methylene blue 1-2 mg/kg/bodyweight intravenously (the dose depending on the severity of the features), whereas those with methaemoglobin concentrations exceeding 50% should be given methylene blue 2 mg/kg intravenously. Symptomatic improvement usually occurs within 30 minutes and a second dose of methylene blue will be required in only very severe cases or if there is evidence of ongoing methaemoglobin formation. Methylene blue is less effective or ineffective in the presence of glucose-6-phosphate dehydrogenase deficiency since its antidotal action is dependent on nicotinamide-adenine dinucleotide phosphate (NADP+). In addition, methylene blue is most effective in intact erythrocytes; efficacy is reduced in the presence of haemolysis. Moreover, in the presence of haemolysis, high dose methylene blue (20-30 mg/kg) can itself initiate methaemoglobin formation. Supplemental antioxidants such as ascorbic acid (vitamin C), N-acetylcysteine and tocopherol (vitamin E) have been used as adjuvants or alternatives to methylene blue with no confirmed benefit. Exchange transfusion may have a role in the management of severe haemolysis or in G-6-P-D deficiency associated with life-threatening methaemoglobinaemia where methylene blue is relatively contraindicated.

Role of Methylene Blue in the Maintenance of Postinduction Hemodynamic Status in Patients with Perforation Peritonitis: A Pilot Study.

PubMed

Senthilnathan, Muthapillai; Cherian, Anusha; Balachander, Hemavathi; Maroju, Nanda Kishore

2017-01-01

Methylene blue is an inhibitor of guanylate cyclase and hence prevents vasoplegia mediated by nitric oxide in patients with sepsis. This study aimed to analyze the effect of methylene blue on blood pressure maintenance following induction of anesthesia in patients presenting with peritonitis. Thirty patients diagnosed to have perforation peritonitis were randomized into two groups (Group MB, Group NS). Patients in Group MB were given injection methylene blue 2 mg/kg over 20 min and patients in Group NS were given 50 ml of normal saline over 20 min, before induction. Heart rate, mean arterial pressure (MAP), cardiac output, and systemic vascular resistance (SVR) were recorded every 5 min for 1 h after infusion. Hemodynamic parameters were analyzed using repeated-measures analysis of variance with Bonferroni's test. Blood gas analysis was analyzed using independent Student's t -test, and P < 0.05 was considered statistically significant. MAP was lower at all-time points in Group NS than Group MB; however, it was statistically significant immediately, and 5 min the following induction. MAP fell from 94.8 ± 11.8 mmHg to 89.2 ± 16.0 mmHg immediate postinduction in Group MB and from 92.1 ± 9.8 mmHg to 74.1 ± 12.6 mmHg in Group NS. MAP and SVR were significantly higher in Group MB, 5 min following induction. No adverse events attributable to methylene blue were noted. Methylene blue contributes to the maintenance of postinduction hemodynamic stability in patients with perforation peritonitis.

The monoamine oxidase inhibition properties of selected structural analogues of methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delport, Anzelle

The thionine dye, methylene blue (MB), is a potent inhibitor of monoamine oxidase (MAO) A, a property that may, at least in part, mediate its antidepressant effects in humans and animals. The central inhibition of MAO-A by MB has also been linked to serotonin toxicity (ST) which may arise when MB is used in combination with serotonergic drugs. Structural analogues and the principal metabolite of MB, azure B, have also been reported to inhibit the MAO enzymes, with all compounds exhibiting specificity for the MAO-A isoform. To expand on the structure-activity relationships (SARs) of MAO inhibition by MB analogues, themore » present study investigates the human MAO inhibition properties of five MB analogues: neutral red, Nile blue, new methylene blue, cresyl violet and 1,9-dimethyl methylene blue. Similar to MB, these analogues also are specific MAO-A inhibitors with cresyl violet (IC{sub 50} = 0.0037 μM), Nile blue (IC{sub 50} = 0.0077 μM) and 1,9-dimethyl methylene blue (IC{sub 50} = 0.018 μM) exhibiting higher potency inhibition compared to MB (IC{sub 50} = 0.07 μM). Nile blue also represents a potent MAO-B inhibitor with an IC{sub 50} value of 0.012 μM. From the results it may be concluded that non-thionine MB analogues (e.g. cresyl violet and Nile blue) also may exhibit potent MAO inhibition, a property which should be considered when using these compounds in pharmacological studies. Benzophenoxazines such as cresyl violet and Nile blue are, similar to phenothiazines (e.g. MB), representative of high potency MAO-A inhibitors with a potential risk of ST. - Highlights: • MB analogues, cresyl violet and Nile blue, are high potency MAO-A inhibitors. • Nile blue also represents a potent MAO-B inhibitor. • Potent MAO-A inhibition should alert to potential serotonin toxicity.« less

[Sensitive determination of Bi3+ by spectrofluorimetry based on graphene oxide-methylene blue system].

PubMed

Zhai, Qiu-ge; Guo, Peng; Zhou, Lin; Liu, Yan-ming

2014-08-01

Graphene oxide was prepared by the modified Hummers method and characterized by field emission scanning electron microscopy. The interaction of graphene with methylene blue was studied by UV absorption, the intensity of two main absorption peaks of methylene blue decreased significantly after the fluorescence was quenched, and the energy transfer didn't occur because the overlap of the absorption spectrum of GO and the emission spectrum of MB is too small. Therefore, the fluorescence quenching of MB and GO was static. When adding a certain amount of Bi3+ in the graphene-methylene blue system, Bi3+ replaces the methylene blue from the graphene-methylene blue complexes because Bi3+ has the smaller volume and is more positively charged. The methylene blue therefore dissociates from the GO-MB complexes, resulting in the recovery of fluorescence of the system. Furthermore, the fluorescence of the system increases with the increase in the amount of Bi3+ due to the enhanced amount of MB in the system. A novel spectrofluorimetric method was therefore developed for the sensitive determination of Bi3+. Some parameters including the concentration of methylene blue, the amount of graphene oxide, the amount of nitric acid and the sequence of reagent adding were optimized to obtain higher sensitivity. The fluorescence of the system was detected at an emission wavelength of 667 nm with excitation at 690 nm. Under the optimized conditions, the concentration of Bi3+ showed good linear relationships with the fluorescence intensity in the range of 0.5-100 micromol x L(-1), with correlation coefficients of r = 0.9955. The limits of detection for Bi3+ was 1.0 x 10(-8) mol x L(-1) (S/N=3). The selectivity of the proposed method was evaluated and the results showed that 1000-fold K+, Ca+, Na+, Mg2+, Cu2+; 100-fold Fe3+, Be2+, SiO2- Al3+, Ni2+, Sb3+, NO3-, Cl-, F-, and 20-fold Pb2+, Hg2+, Cd2+ had negligible interference with the determination of Bi3+. The method has advantages of sensitivity, rapidness and low cost. It was used for the determination of Bi3+ in environmental water samples inclu- ding pond water, rain water and sewage water with recoveries of 93.4%-105.2%.

Featured Molecules: Ascorbic Acid and Methylene Blue

NASA Astrophysics Data System (ADS)

Coleman, William F.; Wildman, Randall J.

2003-05-01

The WebWare molecules of the month for May are featured in several articles in this issue. "Arsenic: Not So Evil After All?" discusses the pharmaceutical uses of methylene blue and its development as the first synthetic drug used against a specific disease. The JCE Classroom Activity "Out of the Blue" and the article "Greening the Blue Bottle" feature methylene blue and ascorbic acid as two key ingredients in the formulation of the blue bottle. You can also see a colorful example of these two molecules in action on the cover. "Sailing on the 'C': A Vitamin Titration with a Twist" describes an experiment to determine the vitamin C (ascorbic acid) content of citrus fruits and challenges students, as eighteenth-century sea captains, to decide the best fruit to take on a long voyage. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

Removal of Methylene Blue from aqueous solution using spent bleaching earth

NASA Astrophysics Data System (ADS)

Saputra, E.; Saputra, R.; Nugraha, M. W.; Irianty, R. S.; Utama, P. S.

2018-04-01

The waste from industrial textile waste is one of the environmental problems, it is required effective and efficient processing. In this study spent bleaching earth was used as absorbent. It was found that the absorbent was effective to remove methylene blue from aqueous solution with removal efficiency 99.97 % in 120 min. Several parameters such as pH, amount of absorbent loading, stirring speed are found as key factor influencing removal of methylene blue. The mechanism of adsorption was also studied, and it was found that Langmuir isotherm fitted to data of experiment with adsorption capacity 0.5 mg/g.

Graphene oxide (rGO)-metal oxide (TiO2/Fe3O4) based nanocomposites for the removal of methylene blue

NASA Astrophysics Data System (ADS)

Banerjee, Soma; Benjwal, Poonam; Singh, Milan; Kar, Kamal K.

2018-05-01

Herein, ternary nanocomposites based on titanium dioxide, ferric oxide and reduced graphene oxide (GO) have been developed for photocatalytic degradation of methylene blue. The nanocomposites are prepared by simple sol-gel and wet assembly methods with varying weight ratio of each components to obtain efficient photocatalytic degradation. Due to the synergistic effect among the three components, a swift removal of methylene blue becomes possible under visible and UV light. The rGO-Fe3O4-TiO2 nanocomposite having composition 1:1:2 has achieved maximum degradation of methylene blue from the aqueous solution. About 99% of the dye has been removed within 6 min under UV irradiation, while in presence of visible light, 94% has been degraded from the wastewater. The enhancement of photocatalytic activity in this ternary system is attributed to the efficient separation of charge carriers from TiO2 to rGO under the exposure of light and the initiation of photo-Fenton reaction due to the incorporated Fe3O4 nanoparticles in presence of H2O2, which provides highly reactive hydroxyl ions that mineralize the pollutants. All these results indicate that these ternary nanocomposites possess great potential for both UV and visible light driven methylene blue destruction from the wastewater.

Microfluidics-based microbubbles in methylene blue solution for photoacoustic and ultrasound imaging

NASA Astrophysics Data System (ADS)

Das, Dhiman; Sivasubramanian, Kathyayini; Yang, Chun; Pramanik, Manojit

2018-02-01

Contrast agents which can be used for more than one bio-imaging technique has gained a lot of attention from researchers in recent years. In this work, a microfluidic device employing a flow-focusing junction, is used for the continuous generation of monodisperse nitrogen microbubbles in methylene blue, an optically absorbing organic dye, for dual-modal photoacoustic and ultrasound imaging. Using an external phase of polyoxyethylene glycol 40 stearate (PEG 40), a non-ionic surfactant, and 50% glycerol solution at a flow rate of 1 ml/hr and gas pressure at 1.75 bar, monodisperse nitrogen microbubbles of diameter 7 microns were obtained. The external phase also contained methylene blue hydrate at a concentration of 1 gm/litre. The monodisperse microbubbles produced a strong ultrasound signal as expected. It was observed that the signal-to-noise (SNR) ratio of the photoacoustic signal for the methylene blue solution in the presence of the monodisperse microbubbles was 68.6% lower than that of methylene blue solution in the absence of microbubbles. This work is of significance because using microfluidics, we can precisely control the bubbles' production rate and bubble size which increases ultrasound imaging efficiency. A uniform size distribution of the bubbles will have narrower resonance frequency bandwidth which will respond well to specific ultrasound frequencies.

A prospective randomized trial comparing patent blue and methylene blue for the detection of the sentinel lymph node in breast cancer patients.

PubMed

Paulinelli, Régis Resende; Freitas-Junior, Ruffo; Rahal, Rosemar Macedo de Souza; Oliveira, Luis Fernando de Pádua; Vilela, Maria Helena Tavares; Moreira, Marise Amaral Rebouças; Alves, Katyane Larissa; Peleja, Marina Berquó; Resende, Tatiane Coelho Capel de

2017-02-01

Methylene blue is more widely available and less expensive than patent blue, with an apparently lower risk of anaphylaxis. The two dyes were compared regarding detection of the sentinel lymph node (SLN). A prospective, randomized trial involved 142 patients with invasive breast carcinoma. Sixty-nine (49.3%) assigned to patent blue (group A) and 71 (50.70%) to methylene blue (group B). Thirty-five patients (25.0%) were clinical stage III or IV; 55 (38.7%) had axillary lymph nodes affected; and 69 (49.3%) underwent neoadjuvant chemotherapy. Two patients were excluded because the dye type was not recorded. Patients and tumor characteristics were similar in both groups. SLNs were identified in 47 women (68.1%) in group A and 43 (60.6%) in group B (p=0.35). SLNs were affected in 22 cases (51.2%) in group A and 21 (48.8%) in group B (p=0.62). The SLN was the only node affected in 12 cases (54.5%) in group A and six (33.3%) in group B (p=0.18). The time and degree of difficulty involved in identifying the SLN were similar in both groups. There were no complications or allergies. Methylene blue performed as well as patent blue in identifying the SLN in breast cancer patients.

Methylene blue, curcumin and ion pairing nanoparticles effects on photodynamic therapy of MDA-MB-231 breast cancer cell.

PubMed

Hosseinzadeh, Reza; Khorsandi, Khatereh

2017-06-01

The aim of current study was to use methylene blue-curcumin ion pair nanoparticles and single dyes as photosensitizer for comparison of photodynamic therapy (PDT) efficacy on MDA-MB-231 cancer cells, also various light sources effect on activation of photosensitizer (PS) was considered. Ion pair nanoparticles were synthesized using opposite charge ions precipitation and lyophilized. The PDT experiments were designed and the effect of PSs and light sources (Red LED (630nm; power density: 30mWcm -2 ) and blue LED (465nm; power density: 34mWcm -2 )) on the human breast cancer cell line were examined. The effect of PS concentration (0-75μg.mL -1 ), incubation time, irradiation time and light sources, and priority in irradiation of blue or red lights were determined. The results show that the ion pairing of methylene blue and curcumin enhance the photodynamic activity of both dyes and the cytotoxicity of ion pair nanoparticles on the MDA-231 breast cancer cell line. Blue and red LED light sources were used for photo activation of photosensitizers. The results demonstrated that both dyes can activate using red light LED better than blue light LED for singlet oxygen producing. Nano scale ion pair precipitating of methylene blue-curcumin enhanced the cell penetrating and subsequently cytotoxicity of both dyes together. Copyright © 2017 Elsevier B.V. All rights reserved.

Intraoperative near infrared fluorescence guided identification of the ureters using low dose methylene blue: a first in human experience.

PubMed

Verbeek, Floris P R; van der Vorst, Joost R; Schaafsma, Boudewijn E; Swijnenburg, Rutger-Jan; Gaarenstroom, Katja N; Elzevier, Henk W; van de Velde, Cornelis J H; Frangioni, John V; Vahrmeijer, Alexander L

2013-08-01

Near infrared fluorescence imaging is a promising technique that offers real-time visual information during surgery. In this study we report the first clinical results to our knowledge of ureteral imaging using near infrared fluorescence after a simple peripheral infusion of methylene blue. Furthermore, we assessed the optimal timing and dose of methylene blue. A total of 12 patients who underwent lower abdominal surgery were included in this prospective feasibility study. Near infrared fluorescence imaging was performed using the Mini-FLARE™ imaging system. To determine optimal timing and dose, methylene blue was injected intravenously at doses of 0.25, 0.5 or 1 mg/kg after exposure of the ureters. Imaging was performed for up to 60 minutes after injection. In all patients both ureters could be clearly visualized within 10 minutes after infusion of methylene blue. The signal lasted at least up to 60 minutes after injection. The mean signal-to-background ratio of the ureter was 2.27 ± 1.22 (4), 2.61 ± 1.88 (4) and 3.58 ± 3.36 (4) for the 0.25, 0.5 and 1 mg/kg groups, respectively. A mixed model analysis was used to compare signal-to-background ratios among dose groups and times, and to assess the relationship between dose and time. A significant difference among time points (p <0.001) was found. However, no difference was observed among dose groups (p = 0.811). This study demonstrates the first successful use of near infrared fluorescence using low dose methylene blue for the identification of the ureters during lower abdominal surgery. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Methylene Blue Attenuates Lung Injury Induced by Hindlimb Ischemia Reperfusion in Rats

PubMed Central

Wang, Liangrong; Chen, Baihui; Lin, Bi; Ye, Yuzhu; Bao, Caiying; Zhao, Xiyue; Jin, Lida

2018-01-01

Objective This study was aimed to investigate the protective effect of methylene blue against lung injury induced by reperfusion of ischemic hindlimb in a rat model. Methods Twenty-four healthy adult male Sprague-Dawley rats were equally randomized into three groups: sham (SM) group, ischemia reperfusion (IR) group, and methylene blue (MB) group. Rats in both IR and MB groups were subjected to 4 h of ischemia by clamping the left femoral artery and then followed by 4 h of reperfusion. Treatment with 1% methylene blue (50 mg/kg) was administrated intraperitoneally at 10 min prior to reperfusion in the MB group. After 4 h of reperfusion, malondialdehyde (MDA) level, myeloperoxidase (MPO), and superoxide dismutase (SOD) activities in lung tissue were detected; inflammatory cytokines, including IL-1β and IL-6, were measured in bronchoalveolar lavage fluid (BALF); correspondingly, the morphological changes and water content in both gastrocnemius muscle and lung samples were evaluated. Results Hindlimb IR caused remarkable morphological abnormalities and edema in both muscle and lung tissues. SOD activity was decreased, both the MPO activity and MDA level in lung tissue, as well as IL-1β and IL-6 levels in BALF, were increased in the IR group (p < 0.05). Compared with the IR group, SOD activity was increased, whereas MPO activity and MDA level in lung tissue and IL-1β and IL-6 levels in BALF were decreased in the MB group (p < 0.05). Also, the histological damage and edema in both lung and muscle tissues were significantly attenuated by the treatment of methylene blue. Conclusion Methylene blue attenuates lung injury induced by hindlimb IR in rats, at least in part, by inhibiting oxidative stress. PMID:29713238

The Use of Ultra-Violet (UV) Light Emitting Diodes (LEDS) in an Advanced Oxidation Process (AOP) with Brilliant Blue FCF as an Indicator

DTIC Science & Technology

2015-03-26

by low, direct current voltage, which are consistent with portable power sources such as batteries or photovoltaic cells (Crystal IS 2013...of Methylene Blue Adsorption on Power Output .................23 vii UV LED Quartz Lens Adsorption Experiment...29 Effect of Methylene Blue Adsorption on Power Output ............................................29 Figure 5 - Percent reduction of

EFFECT OF METHYLENE BLUE ON DEVELOPING ZEBRAFISH EMBRYOS Danio rerio

EPA Science Inventory

EFFECT OF METHYLENE BLUE ON DEVELOPING ZEBRAFISH EMBRYOS Danio rerioJoan M. Hedge*, Erik Sanders, Kimberly A. Jarema, Deborah Hunter, and Stephanie PadillaIntegrated Systems Toxicology Division, NHEERL, US EPA, Research Triangle Park, NC 27709hedge.joan@epa.govOur laboratory rout...

Photodynamic action of the red laser on Propionibacterium acnes*

PubMed Central

Ramos, Rogério Rodrigo; de Paiva, Jeferson Leandro; Gomes, José Paulo Franco dos Santos; Boer, Nagib Pezati; de Godoy, José Maria Pereira; Batigalia, Fernando

2017-01-01

Background Photodynamic therapy is a therapeutic modality that has consolidated its activity in the photooxidation of organic matter, which arises from the activity of reactive oxygen species. Objective To evaluate the effect of red laser 660nm with the photosensitizer methylene blue on Propionibacterium acnes in vitro. Method The experimental design was distributed into four groups (1 - control group without the application of light and without photosensitizer, 2 - application of light, 3 - methylene blue without light, and 4 - methylene blue with light). Tests were subjected to red laser irradiation 660nm by four cycles of 5 minutes at 3-minute intervals. Results It was evidenced the prominence of the fourth cycle (20 minutes) groups 2, 3 and 4. Study limitations Despite the favorable results, the laser irradiation time photosensitizer associated with methylene blue were not sufficient to to completely inhibit the proliferation of bacteria. Conclusion Further studies in vitro are recommended to enable the clinical application of this photosensitizer in photodynamic therapy. PMID:29166495

Modified use of methylene blue in the tissue compression technique to detect sarcocysts in meat-producing animals.

PubMed

Ng, Yit Han; Subramaniam, Vellayan; Lau, Yee Ling

2015-11-30

Sarcocystosis in meat-producing animals is a major cause of reduced productivity in many countries, especially those that rely on agriculture. Although several diagnostic methods are available to detect sarcocystosis, many are too time-consuming for routine use in abattoirs and meat inspection centers, where large numbers of samples need to be tested. This study aimed to compare the sensitivity of the methylene blue tissue preparation, unstained tissue preparation and nested PCR in the detection of sarcocysts in tissue samples. Approximately three-fold more sarcocysts were detected in methylene blue-stained tissue compared to unstained controls (McNemar's test: P<0.01). Test sensitivity was comparable to that of the gold standard for sarcocyst detection, nested polymerase chain reaction. These results suggest that methylene blue can be used in tissue compression as a rapid, safe, and inexpensive technique for the detection of ruminant sarcocystosis in abattoirs. Copyright © 2015 Elsevier B.V. All rights reserved.

Methylene blue protects against TDP-43 and FUS neuronal toxicity in C. elegans and D. rerio.

PubMed

Vaccaro, Alexandra; Patten, Shunmoogum A; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J Alex

2012-01-01

The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress.

Methylene Blue Protects against TDP-43 and FUS Neuronal Toxicity in C. elegans and D. rerio

PubMed Central

Vaccaro, Alexandra; Patten, Shunmoogum A.; Ciura, Sorana; Maios, Claudia; Therrien, Martine; Drapeau, Pierre; Kabashi, Edor; Parker, J. Alex

2012-01-01

The DNA/RNA-binding proteins TDP-43 and FUS are found in protein aggregates in a growing number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and related dementia, but little is known about the neurotoxic mechanisms. We have generated Caenorhabditis elegans and zebrafish animal models expressing mutant human TDP-43 (A315T or G348C) or FUS (S57Δ or R521H) that reflect certain aspects of ALS including motor neuron degeneration, axonal deficits, and progressive paralysis. To explore the potential of our humanized transgenic C. elegans and zebrafish in identifying chemical suppressors of mutant TDP-43 and FUS neuronal toxicity, we tested three compounds with potential neuroprotective properties: lithium chloride, methylene blue and riluzole. We identified methylene blue as a potent suppressor of TDP-43 and FUS toxicity in both our models. Our results indicate that methylene blue can rescue toxic phenotypes associated with mutant TDP-43 and FUS including neuronal dysfunction and oxidative stress. PMID:22848727

Erythrocyte membrane alterations as the basis of chlorate toxicity.

PubMed

Singelmann, E; Wetzel, E; Adler, G; Steffen, C

1984-03-01

The effects of sodium chlorate and of sodium nitrite on human erythrocytes were studied in vitro. Nitrite rapidly oxidised haemoglobin and glutathione; reduction of methaemoglobin (Hbi) by methylene blue was complete during 3 h of incubation with nitrite. With chlorate, a concentration-dependent lag phase was seen before Hbi was formed. After prolonged incubation, Hbi could no longer be reduced with methylene blue. Several other effects were observed that explain the clinical picture of chlorate poisoning which involves haemolysis followed by disseminated intravascular coagulation and renal failure: increased permeability to cations, increased resistance to hypotonic haemolysis and prolonged filtration time through polycarbonate membranes with cylindrical pores of 5 micron diameter. This suggests an increased membrane rigidity due to membrane protein polymerisation, as demonstrated by SDS polyacrylamide gel electrophoresis. Simultaneously, erythrocyte enzymes were inactivated, primarily glucose-6-phosphate dehydrogenase which is necessary for the therapeutic effect of methylene blue. This explains the inefficacy of methylene blue in the treatment of a case of chlorate poisoning that we observed (Arch. Toxicol., 48 (1981) 281).

[Methemoglobinemia after inhalation of poppers].

PubMed

Janssens, U; Hillen, S; Janssens, T; Grafe, J

2018-04-17

This case report presents a case of symptomatic methemoglobinemia (MetHb 31.6%) after inhalation of volatile nitrites (poppers). The patient's medical history and symptoms are discussed together with pathophysiology of methemoglobinemia, diagnostics, and antidote therapy. Pulse oxymetry, arterial blood gas analysis, and CO-oximetry receive particular attention as well as antidote therapy with methylene blue. The patient was treated successfully with intravenous methylene blue. Within 60 min methemoglobinemia returned to normal values (MetHb 0.6%). Stimulating compounds such as volatile nitrites (poppers) may lead to potentially fatal methemoglobinemia. Swift and accurate diagnosis and targeted therapy with methylene blue can lead to rapid recovery.

The efficacy of methylene blue encapsulated in silica nanoparticles compared to naked methylene blue for photodynamic applications.

PubMed

Makhadmeh, Ghaseb Naser; Abdul Aziz, Azlan; Abdul Razak, Khairunisak

2016-05-01

This study analyzed the physical effects of methylene blue (MB) encapsulated within silica nanoparticles (SiNPs) in photodynamic therapy. The optimum concentration of MB needed to destroy red blood cells (RBCs) was determined, and the efficacy of encapsulated MB-SiNPs compared to that of naked MB was verified. The results confirmed the applicability of MB encapsulated in SiNPs on RBCs, and established a relationship between the concentration of the SiNP-encapsulated MB and the time required to rupture 50% of the RBCs (t50). The MB encapsulated in SiNPs exhibited higher efficacy compared to that of naked MB.

In vivo lymph node mapping by Cadmium Tellurium quantum dots in rats.

PubMed

Si, Chengshuai; Zhang, Yunpeng; Lv, Xianbo; Yang, Wuli; Ran, Zhipeng; Sun, Peng

2014-12-01

Intraoperative lymph node mapping (LNM) is highly significant for many surgeries in patients with cancer. Many types of tracers are currently used, but the ideal method has not yet been identified. We aimed to identify a stable lymphatic drainage pathway in an animal model and compared the effects of quantum dots (QD), a new fluorescent tracer, with those of methylene blue in intraoperative LNM. Indian ink (0.2 mL) was subcutaneously injected into the plantar metatarsal regions of six Sprague-Dawley rats. After 2 wk of incubation and subsequent dissection, the potentially stained LNs were examined pathologically to identify the lymphatic drainage pathway. After applying anesthesia, 0.1 mL methylene blue (2%) and QD (1 mg/mL) were injected into the plantar metatarsal regions of six rats for intraoperative LNM. The QD group was observed with a near-infrared imaging system, and the methylene blue group was directly observed. Drainages were recorded at 5, 10, 30, 60, and 120 min and at 1 d. Two three-level drainage pathways, that is, a peripheral drainage (popliteal LNs, inguinal LNs, and axillary LNs) and a central drainage (popliteal lymph node [LN], iliac LN, and renal LN) pathways were identified. Both methylene blue and QD stained the sentinel lymph node (SLNs) quickly, but methylene blue was difficult to identify in the deep tissues and the LNs beyond the SLN. Furthermore, the blue-stained LNs remain dyed for only 2 h. In contrast, the QDs exhibited high target-to-background ratios in both the SLNs and the following LNs. Additionally, the fluorescence lasted from 5 min-1 d after injection. An ideal lymphatic drainage model was found. QDs are excellent tracers for intraoperative LNM compared with methylene blue. Near infrared fluorescent imaging is a promising LNM method for clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Degradation of organic pollutants by Ag, Cu and Sn doped waste non-metallic printed circuit boards.

PubMed

Ramaswamy, Kadari; Radha, Velchuri; Malathi, M; Vithal, Muga; Munirathnam, Nagegownivari R

2017-02-01

The disposal and reuse of waste printed circuit boards have been the major global concerns. Printed circuit boards, a form of Electronic waste (hereafter e-waste), have been chemically processed, doped with Ag + , Cu 2+ and Sn 2+ , and used as visible light photocatalysts against the degradation of methylene blue and methyl violet. The elemental analyses of pristine and metal doped printed circuit board were obtained using energy dispersive X-ray fluorescence (EDXRF) spectra and inductively coupled plasma optical emission spectroscopy (ICP-OES). The morphology of parent and doped printed circuit board was obtained from scanning electron microscopy (SEM) measurements. The photocatalytic activity of parent and metal doped samples was carried out for the decomposition of organic pollutants, methylene blue and methyl violet, under visible light irradiation. Metal doped waste printed circuit boards (WPCBs) have shown higher photocatalytic activity against the degradation of methyl violet and methylene blue under visible light irradiation. Scavenger experiments were performed to identify the reactive intermediates responsible for the degradation of methylene blue and methyl violet. The reactive species responsible for the degradation of MV and MB were found to be holes and hydroxyl radicals. A possible mechanism of degradation of methylene blue and methyl violet is given. The stability and reusability of the catalysts are also investigated. Copyright © 2016. Published by Elsevier Ltd.

Methylene blue adsorption by algal biomass based materials: biosorbents characterization and process behaviour.

PubMed

Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

2007-08-17

Dead algal biomass is a natural material that serves as a basis for developing a new family of sorbent materials potentially suitable for many industrial applications. In this work an algal industrial waste from agar extraction process, algae Gelidium and a composite material obtained by immobilization of the algal waste with polyacrylonitrile (PAN) were physical characterized and used as biosorbents for dyes removal using methylene blue as model. The apparent and real densities and the porosity of biosorbents particles were determined by mercury porosimetry and helium picnometry. The methylene blue adsorption in the liquid phase was the method chosen to calculate the specific surface area of biosorbent particles as it seems to reproduce better the surface area accessible to metal ions in the biosorption process than the N2 adsorption-desorption dry method. The porous texture of the biosorbents particles was also studied. Equilibrium isotherms are well described by the Langmuir equation, giving maximum uptake capacities of 171, 104 and 74 mg g(-1), respectively for algae, algal waste and composite material. Kinetic experiments at different initial methylene blue concentrations were performed to evaluate the equilibrium time and the importance of the driving force to overcome mass transfer resistances. The pseudo-first-order and pseudo-second-order kinetic models adequately describe the kinetic data. The biosorbents used in this work proved to be promising materials for removing methylene blue from aqueous solutions.

Comparison of two modalities: a novel technique, 'chromohysteroscopy', and blind endometrial sampling for the evaluation of abnormal uterine bleeding.

PubMed

Alay, Asli; Usta, Taner A; Ozay, Pinar; Karadugan, Ozgur; Ates, Ugur

2014-05-01

The objective of this study was to compare classical blind endometrial tissue sampling with hysteroscopic biopsy sampling following methylene blue dyeing in premenopausal and postmenopausal patients with abnormal uterine bleeding. A prospective case-control study was carried out in the Office Hysteroscopy Unit. Fifty-four patients with complaints of abnormal uterine bleeding were evaluated. Data of 38 patients were included in the statistical analysis. Three groups were compared by examining samples obtained through hysteroscopic biopsy before and after methylene blue dyeing, and classical blind endometrial tissue sampling. First, uterine cavity was evaluated with office hysteroscopy. Methylene blue dye was administered through the hysteroscopic inlet. Tissue samples were obtained from stained and non-stained areas. Blind endometrial sampling was performed in the same patients immediately after the hysteroscopy procedure. The results of hysteroscopic biopsy from methylene blue stained and non-stained areas and blind biopsy were compared. No statistically significant differences were determined in the comparison of biopsy samples obtained from methylene-blue stained, non-stained areas and blind biopsy (P > 0.05). We suggest that chromohysteroscopy is not superior to endometrial sampling in cases of abnormal uterine bleeding. Further studies with greater sample sizes should be performed to assess the validity of routine use of endometrial dyeing. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Visible light induced photobleaching of methylene blue over melamine-doped TiO2 nanocatalyst

EPA Science Inventory

TiO2 doping with N-rich melamine produced a stable, active and visible light sentisized nanocatalyst that showed a remarkable efficiency towards the photobleaching of a model compound – methylene blue (MB) in aqueous solution. The photobleaching followed a mixed reaction order ki...

Extinction Memory Improvement by the Metabolic Enhancer Methylene Blue

ERIC Educational Resources Information Center

Gonzalez-Lima, F.; Bruchey, Aleksandra K.

2004-01-01

We investigated whether postextinction administration of methylene blue (MB) could enhance retention of an extinguished conditioned response. MB is a redox compound that at low doses elevates cytochrome oxidase activity, thereby improving brain energy production. Saline or MB (4 mg/kg intraperitoneally) were administered to rats for 5 d following…

A convenient method for determining the concentration of hydrogen in water: use of methylene blue with colloidal platinum

PubMed Central

2012-01-01

A simple titration (oxidimetry) method using a methylene blue-platinum colloid reagent is effective in determining the concentration of hydrogen gas in an aqueous solution. The method performs as effectively as the more complex and expensive electrochemical method. PMID:22273079

THE EFFECT OF METHYLENE BLUE ADDITION TO WHOLE BLOOD DURING PROLONGED STORAGE.

DTIC Science & Technology

reductase. The levels of adenosinetriphosphate were not affected by the addition of MB. However, the 2,3- diphosphoglycerate levels remained higher than...Addition of methylene blue (MB) in concentrations of 0.001 to 0.00001 M to CPD blood resulted in lowered levels of glutathione and glutathione

Solid waste from leather industry as adsorbent of organic dyes in aqueous-medium.

PubMed

Oliveira, Luiz C A; Gonçalves, Maraísa; Oliveira, Diana Q L; Guerreiro, Mário C; Guilherme, Luiz R G; Dallago, Rogério M

2007-03-06

The industrial tanning of leather usually produces considerable amounts of chromium-containing solid waste and liquid effluents and raises many concerns on its environmental effect as well as on escalating landfill costs. Actually, these shortcomings are becoming increasingly a limiting factor to this industrial activity that claims for alternative methods of residue disposals. In this work, it is proposed a novel alternative destination of the solid waste, based on the removal of organic contaminants from the out coming aqueous-residue. The adsorption isotherm pattern for the wet blue leather from the Aurea tanning industry in Erechim-RS (Brazil) showed that these materials present high activity on adsorbing the reactive red textile dye as well as other compounds. The adsorbent materials were characterized by IR spectroscopy and SEM and tested for the dye adsorption (reactive textile and methylene blue dyes). The concentrations of dyes were measured by UV-vis spectrophotometry and the chromium extraction from leather waste was realized by basic hydrolysis and determined by atomic absorption. As a low cost abundant adsorbent material with high adsorption ability on removing dye methylene blue (80mgg(-1)) and textile dye reactive red (163mgg(-1)), the leather waste is revealed to be a interesting alternative relatively to more costly adsorbent materials.

Graphene oxide functionalized with methylene blue and its performance in singlet oxygen generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojtoniszak, M., E-mail: mwojtoniszak@zut.edu.pl; Rogińska, D.; Machaliński, B.

2013-07-15

Graphical abstract: - Highlights: • Adsorption of methylene blue (MB) on graphene oxide (GO). • Characterization of graphene oxide–methylene blue nanocomposite (MB–GO). • Examination of MB–GO efficiency in singlet oxygen generation (SOG). • MB–GO performs higher SOG efficiency than pristine MB. - Abstract: Due to unique electronic, mechanical, optical and structural properties, graphene has shown promising applications in many fields, including biomedicine. One of them is noninvasive anticancer therapy – photodynamic therapy (PDT), where singlet oxygen (SO), generated under the irradiation of light with appropriate wavelengths, kills cancer cells. In this study, authors report graphene oxide (GO) noncovalent functionalization withmore » methylene blue (MB). MB molecules underwent adsorption on the surface of GO. Detailed characterization of the obtained material was carried out with UV–vis spectroscopy, Raman spectroscopy, FT-IR spectroscopy, and confocal laser scanning microscopy. Furthermore, its performance in singlet oxygen generation (SOG) under irradiation of laser with excitation wavelengths of 785 nm was investigated. Interestingly, GO functionalized with MB (MB–GO) showed enhanced efficiency in singlet oxygen generation compared to pristine MB. The efficiency in SOG was detected by photobleaching of 9,10-anthracenediyl-bis(methylene)dimalonic acid (ABMDMA). These results indicate the material is promising in PDT anticancer therapy and further in vitro and in vivo studies are required.« less

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

NASA Astrophysics Data System (ADS)

Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan; Zhou, Zhiqin

2016-11-01

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater.

Water-insoluble sericin/β-cyclodextrin/PVA composite electrospun nanofibers as effective adsorbents towards methylene blue.

PubMed

Zhao, Rui; Wang, Yong; Li, Xiang; Sun, Bolun; Jiang, Ziqiao; Wang, Ce

2015-12-01

A novel water-insoluble sericin/β-cyclodextrin/poly (vinyl alcohol) composite nanofiber adsorbent was prepared by electrospinning and followed by thermal crosslinking for removal of cationic dye methylene blue from aqueous solution. Fourier transform infrared spectroscopy and solubility experiments confirmed that sericin and β-cyclodextrin were incorporated into the nanofibers and the crosslinking reaction occurred successfully. Kinetics, isotherms and thermodynamics analysis were studied for adsorption of methylene blue. The adsorption process is better fitted with the pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacities are 187.97, 229.89, and 261.10mg/g at the temperatures 293, 313 and 333 K, respectively. Thermodynamic parameters showed that methylene blue adsorption was endothermic and spontaneous. In addition, the fiber membrane adsorbent could be easily separated from dye solution and showed high recyclable removal efficiency. All these results suggest that crosslinked sericin/β-cyclodextrin/poly(vinyl alcohol) composite nanofibers could be potential recyclable adsorbents in dye wastewater treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrochemical preparation of poly(methylene blue)/graphene nanocomposite thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erçarıkcı, Elif; Dağcı, Kader; Topçu, Ezgi

2014-07-01

Highlights: • Poly(MB)/graphene thin films are prepared by a simple electrochemical approach. • Graphene layers in the film show a broad band in visible region of absorbance spectra. • Morphology of composite films indicates both disordered and ordered regions. • XRD reveals that nanocomposite films include rGO layers after electropolymerization process. • Chemically prepared graphene is better than electrochemically prepared graphene for electrooxidation of nitrite. - Abstract: Poly(methylene blue)/graphene nanocomposite thin films were prepared by electropolymerization of methylene blue in the presence of graphene which have been synthesized by two different methods of a chemical oxidation process and an electrochemicalmore » approach. Synthesized nanocomposite thin films were characterized by using cyclic voltammetry, UV–vis. absorption spectroscopy, powder X-ray diffraction, and scanning tunneling microscopy techniques. Electrocatalytical properties of prepared poly(methylene blue)/graphene nanocomposite films were compared toward electrochemical oxidation of nitrite. Under optimized conditions, electrocatalytical effect of nanocomposite films of chemically prepared graphene through electrochemical oxidation of nitrite was better than that of electrochemically prepared graphene.« less

Methylene Blue: The Long and Winding Road from Stain to Brain: Part 1.

PubMed

Howland, Robert H

2016-09-01

Methylene blue, first discovered and used as a dye in the textile industry, has long been used for biological staining in histology, bacteriology, and hematology. Because of its unique physiochemical properties, it was the first synthetic drug used in medicine, having been used to treat malaria more than one century ago. Methylene blue was also one of the first drugs used for the treatment of patients with psychosis at the end of the 19th century and was the lead drug in the serendipitous development of phenothiazine antipsychotic drugs in the mid-20th century. It was studied in bipolar disorder in the 1980s and has been investigated in neurodegenerative disorders in recent years. The history of methylene blue from its discovery as a dye to its use as a stain and then its therapeutic application in medicine is an example of how a drug's use can evolve over time through careful observation, clinical needs, serendipity, and the integration of concepts from different disciplines. [Journal of Psychosocial Nursing and Mental Health Services, 54(9), 21-24.]. Copyright 2016, SLACK Incorporated.

Individual marking of soft-bodied subtidal invertebrates in situ – A novel staining technique applied to the giant plumose anemone Metridium farcimen (Tilesius, 1809)

PubMed Central

Sebens, Kenneth P.

2017-01-01

The ability to recognize individuals and track growth over time is crucial to population dynamics research as well as studies of animal behavior. Invertebrates are particularly difficult to track as they often molt, have regenerative capabilities, or lack hard parts to attach markers. We tested, in laboratory and field studies, a new way of marking sea anemones (order Actiniaria) by injection of three vital stains (i.e., neutral red, methylene blue, and fluorescein). Neutral red and methylene blue did not affect growth or survival, but fluorescein was lethal at high concentrations. Marked individuals could be identified up to seven months after injection with neutral red, six weeks with methylene blue, and three days with low concentrations of fluorescein. Neutral red could be used for long-term monitoring of growth and survival in the field, and in combination with methylene blue could be used to mark individuals in distinguishable patterns for short-term studies such as examining predator-prey interactions, movement of individuals, and recruitment survival. PMID:29161292

Nanoparticle-mediated combination chemotherapy and photodynamic therapy overcomes tumor drug resistance in vitro.

PubMed

Khdair, Ayman; Handa, Hitesh; Mao, Guangzhao; Panyam, Jayanth

2009-02-01

Drug resistance limits the success of many anticancer drugs. Reduced accumulation of the drug at its intracellular site of action because of overexpression of efflux transporters such as P-glycoprotein (P-gp) is a major mechanism of drug resistance. In this study, we investigated whether photodynamic therapy (PDT) using methylene blue, also a P-gp inhibitor, can be used to enhance doxorubicin-induced cytotoxicity in drug-resistant tumor cells. Aerosol OT (AOT)-alginate nanoparticles were used as a carrier for the simultaneous cellular delivery of doxorubicin and methylene blue. Methylene blue was photoactivated using light of 665 nm wavelength. Induction of apoptosis and necrosis following treatment with combination chemotherapy and PDT was investigated in drug-resistant NCI/ADR-RES cells using flow cytometry and fluorescence microscopy. Effect of encapsulation in nanoparticles on the intracellular accumulation of doxorubicin and methylene blue was investigated qualitatively using fluorescence microscopy and was quantitated using HPLC. Encapsulation in AOT-alginate nanoparticles significantly enhanced the cytotoxicity of combination therapy in resistant tumor cells. Nanoparticle-mediated combination therapy resulted in a significant induction of both apoptosis and necrosis. Improvement in cytotoxicity could be correlated with enhanced intracellular and nuclear delivery of the two drugs. Further, nanoparticle-mediated combination therapy resulted in significantly elevated reactive oxygen species (ROS) production compared to single drug treatment. In conclusion, nanoparticle-mediated combination chemotherapy and PDT using doxorubicin and methylene blue was able to overcome resistance mechanisms and resulted in improved cytotoxicity in drug-resistant tumor cells.

A study of the treatment of cutaneous fungal infection in animal model using photoactivated composite of methylene blue and gold nanoparticle.

PubMed

Tawfik, Abeer Attia; Noaman, Islam; El-Elsayyad, Hasan; El-Mashad, Noha; Soliman, Mona

2016-09-01

Onychomycosis is a widespread public health problem, in which T. rubrum and T. mentagrophytes is the commenest causative organisms. Current medical therapy has many drawbacks and side effects. Methylene blue (m.b) photodynamic therapy (pdt) proved efficacy but with lengthy sessions. Optimizing methylene blue photodynamic therapy by combination of methylene blue photosensitizer and gold nanoparticles (aunps) in a composite as gold nanoparticles are efficient delivery systems and efficient enhancers of photosensitizers for antifungal photodynamic therapy. Eighty newzealand rabbit (Oryctolagus cuniculus) were used and categorized in eight equal groups as follows; healthy and infection control, composite photodynamic therapy and five comparative groups. Photodynamic therapy was initiated at day three to five post inoculation, for four sessions forty eight hours apart. Each group divided and light exposure at two fluencies; 80J and 100J. All groups were investigated macroscopically and microscopically (histopathology and scanning electron microscope) also flowcytometry assessment for cell death and X-ray analysis for gold nanoparticles accumulation in brain and liver tissues were determined. Recovery from infection approaching 96% in gold nanoparticles+light group, around 40% in methylene blue photodynamic therapy and 34% in composite photodynamic therapy. The observed findings confirmed by apparent decrease of apoptosis, however small amounts of gold nanoparticles detected in brain and liver. Light stimulated gold nanoparticles is a promising tool in treatment of onychomycosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Study on Photocatalytic Properties of TiO2 Nanoparticle in various pH condition

NASA Astrophysics Data System (ADS)

Nasikhudin; Diantoro, M.; Kusumaatmaja, A.; Triyana, K.

2018-04-01

Titanium dioxide has been widely studied for its ability to photocatalytic and applications have high performance for photovoltaic applications. In this paper TiO2 nanoparticle was investigated for the degradation of methylene blue under UV light in various pH condition. The TiO2 nanoparticle was characterized by SEM and XRD. The results showed that TiO2 nanoparticle has the structure of anatase and have a particle size of 27 nm. The photocatalytic activity of TiO2 nanoparticle show that the degradation of methylene blue under UV light have dye removal of 97% dye was degraded in 3 h, but the degradation of methylene blue without UV light have dye removal of 15% dye was degraded in 3 h. It indicated that The photocatalytic activity of TiO2 nanoparticle could occur if there the UV light. If not UV light the photocatalytic activity cannot occurs, the degradation of Methylene Blue 15% is not a photocatalytic activity but it is adsorption of Methylene Blue by TiO2 nanoparticle. The photocatalytic activity of TiO2 nanoparticle has pH-sensitive. The photocatalytic activity of TiO2 nanoparticle in acid condition (pH 4.1) is 40%, in neutral condition (pH 7.0) is 90%, and in base condition (pH 9.7) is 97%. The highest photocatalytic activity occurs in base condition, it causes in base condition OH- can be direct reaction with a hole to produce hydroxyl radical (OH*).

Intraoperatively Testing the Anastomotic Integrity of Esophagojejunostomy Using Methylene Blue.

PubMed

Celik, S; Almalı, N; Aras, A; Yılmaz, Ö; Kızıltan, R

2017-03-01

Intraoperative testing of gastrointestinal anastomosis effectively ensures anastomotic integrity. This study investigated whether the routine use of methylene blue intraoperatively identified leaks to reduce the postoperative proportion of clinical leaks. This study retrospectively analyzed consecutive total gastrectomies performed from January 2007 to December 2014 in a university hospital setting by a general surgical group that exclusively used the methylene blue test. All surgeries were performed for gastric or junctional cancers (n = 198). All reconstructions (Roux-en Y esophagojejunostomy) were performed using a stapler. The methylene blue test was used in 108 cases (group 1) via a nasojejunal tube. No test was performed for the other 90 cases (group 2). Intraoperative leakage rate, postoperative clinical leakage rate, length of hospitalization, and mortality rate were the outcome measures. The intraoperative leakage rate was 7.4% in group 1. The postoperative clinical leakage rate was 8.6%. The postoperative clinical leakage rate was 3.7% in group 1 and 14.4% in group 2 (p = 0.007). There were no postoperative clinical leaks when an intraoperative leak led to concomitant intraoperative repair. The median length of hospital stay was 6 days in group 1 and 8 days in group 2 (p < 0.001). One death occurred in each group. No test-related complications were observed. The methylene blue test for esophagojejunostomy is a safe and reliable method for the assessment of anastomosis integrity, especially in cases with difficult esophagojejunostomic construction.

Methylene blue induced morphological deformations in Plasmodium falciparum gametocytes: implications for transmission-blocking.

PubMed

Wadi, Ishan; Pillai, C Radhakrishna; Anvikar, Anupkumar R; Sinha, Abhinav; Nath, Mahendra; Valecha, Neena

2018-01-08

Malaria remains a global health problem despite availability of effective tools. For malaria elimination, drugs targeting sexual stages of Plasmodium falciparum need to be incorporated in treatment regimen along with schizonticidal drugs to interrupt transmission. Primaquine is recommended as a transmission blocking drug for its effect on mature gametocytes but is not extensively utilized because of associated safety concerns among glucose-6-phosphate dehydrogenase (G6PD) deficient patients. In present work, methylene blue, which is proposed as an alternative to primaquine is investigated for its gametocytocidal activity amongst Indian field isolates. An effort has been made to establish Indian field isolates of P. falciparum as in vitro model for gametocytocidal drugs screening. Plasmodium falciparum isolates were adapted to in vitro culture and induced to gametocyte production by hypoxanthine and culture was enriched for gametocyte stages using N-acetyl-glucosamine. Gametocytes were incubated with methylene blue for 48 h and stage specific gametocytocidal activity was evaluated by microscopic examination. Plasmodium falciparum field isolates RKL-9 and JDP-8 were able to reproducibly produce gametocytes in high yield and were used to screen gametocytocidal drugs. Methylene blue was found to target gametocytes in a concentration dependent manner by either completely eliminating gametocytes or rendering them morphologically deformed with mean IC 50 (early stages) as 424.1 nM and mean IC 50 (late stages) as 106.4 nM. These morphologically altered gametocytes appeared highly degenerated having shrinkage, distortions and membrane deformations. Field isolates that produce gametocytes in high yield in vitro can be identified and used to screen gametocytocidal drugs. These isolates should be used for validation of gametocytocidal hits obtained previously by using lab adapted reference strains. Methylene blue was found to target gametocytes produced from Indian field isolates and is proposed to be used as a gametocytocidal adjunct with artemisinin-based combination therapy. Further exploration of methylene blue in clinical studies amongst Indian population, including G6PD deficient patients, is recommended.

Intradiskal methylene blue treatment for diskogenic low back pain.

PubMed

Levi, David S; Horn, Scott; Walko, Edward

2014-11-01

Low back pain is a leading cause of pain and disability. The intervertebral disk has been identified as the most common source of chronic low back pain. Although prior treatments directed at intervertebral disks have been disappointing, recent studies show promising improvement of pain and function after a single intradiskal injection of methylene blue. To assess changes in pain and function in patients with diskogenic low back pain, diagnosed by diskography, after an intradiskal injection of methylene blue. Prospective trial. Patients diagnosed with diskogenic pain by diskography underwent a single treatment of intradiskal injection of methylene blue, determined by prior provocation diskography. Pain and function measurements were completed at baseline and 1, 2, and 6 months after treatment. Treatment was considered a categorical success based on a 30% improvement in pain according to a visual analog scale (VAS) and function on the Oswestry Disability Index (ODI). Treatment was considered a categorical failure if less than 30% improvement in pain and function was achieved or if the patient pursued other invasive treatment options during the trial period. Sixteen patients received the intradiskal methylene blue injection. Eleven patients received a single-level injection, 4 patients received a 2-level injection, and one patient received injections at 3 levels. For the VAS, at 1, 2, and 6 months after the injection, the categorical success rates were 25%, 21%, and 25%, respectively. For the ODI, at 1, 2 and 6 months after the injection, the categorical success rates were 25%, 21%, and 33%, respectively. The overall categorical success rates at 1, 2, and 6 months after the injection were 19%, 21%, and 25%, respectively. This small trial did not demonstrate overall clinical success of intradiskal methylene blue injection for patients diagnosed with diskogenic pain by diskography. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

The Blue Bottle Revisited.

ERIC Educational Resources Information Center

Vandaveer, Walter R., IV; Mosher, Mel

1997-01-01

Presents a modification of the classic Blue Bottle demonstration that involves the alkaline glucose reduction of methylene blue. Uses other indicators in the classic Blue Bottle to produce a rainbow of colors. (JRH)

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapidmore » adsorption rate and good reusability toward removal of MB.« less

Intravenous methylene blue venography during laparoscopic paediatric varicocelectomy.

PubMed

Keene, David J B; Cervellione, Raimondo M

2014-02-01

One of the challenges of varicocele surgery is to prevent hydrocele formation while still ensuring success. Methylene blue has been used to identify and preserve lymphatic vessels, and venography has been a standard component of sclerotherapy and percutaneous retrograde techniques. The authors have combined both approaches during laparoscopic varicocelectomy and report their experience. A prospective study was performed of adolescents with idiopathic varicocele and spontaneous venous reflux on Doppler ultrasound. A pampiniform plexus vein was cannulated via scrotal incision before creating the pneumoperitoneum. A mixture of methylene blue and Omnipaque™ was injected into the pampiniform plexus with fluoroscopic screening. Laparoscopic selective vein ligation was then performed using 5mm endoscopic clips or a bipolar vessel sealing device such as Plasmakinetic™ or Ligasure™. Venography was repeated to confirm complete ligation of the internal testicular veins. Patients were followed-up at 3, 6, and 9 months post-surgery with clinical examination and Doppler ultrasound. Data are presented as median (interquartile range). Twenty-four patients underwent laparoscopic selective vein ligation with venography and methylene blue injection. The median age was 14.7 (14.6-15.7) years. The recurrence rate was 12%. No patients developed a hydrocele. The length of surgery was 120 (100-126) minutes. Intra-operative intra-venous methylene blue injection and venography helps to identify venous duplications of the internal testicular veins and enhances the success rate of laparoscopic selective vein ligation. This approach prevents hydrocele formation but has a 12% recurrence rate, which appears to be higher than some techniques described in the literature. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimization of methylene blue using Ca(2+) and Zn(2+) bio-polymer hydrogel beads: A comparative study.

PubMed

Kumar, M; Tamilarasan, R; Arthanareeswaran, G; Ismail, A F

2015-11-01

Recently noted that the methylene blue cause severe central nervous system toxicity. It is essential to optimize the methylene blue from aqueous environment. In this study, a comparison of an optimization of methylene blue was investigated by using modified Ca(2+) and Zn(2+) bio-polymer hydrogel beads. A batch mode study was conducted using various parameters like time, dye concentration, bio-polymer dose, pH and process temperature. The isotherms, kinetics, diffusion and thermodynamic studies were performed for feasibility of the optimization process. Freundlich and Langmuir isotherm equations were used for the prediction of isotherm parameters and correlated with dimensionless separation factor (RL). Pseudo-first order and pseudo-second order Lagegren's kinetic equations were used for the correlation of kinetic parameters. Intraparticle diffusion model was employed for diffusion of the optimization process. The Fourier Transform Infrared Spectroscopy (FTIR) shows different absorbent peaks of Ca(2+) and Zn(2+) beads and the morphology of the bio-polymer material analyzed with Scanning Electron Microscope (SEM). The TG & DTA studies show that good thermal stability with less humidity without production of any non-degraded products. Copyright © 2015 Elsevier Inc. All rights reserved.

Optimization of banana trunk-activated carbon production for methylene blue-contaminated water treatment

NASA Astrophysics Data System (ADS)

Danish, Mohammed; Ahmad, Tanweer; Nadhari, W. N. A. W.; Ahmad, Mehraj; Khanday, Waheed Ahmad; Ziyang, Lou; Pin, Zhou

2018-03-01

This experiment was run to characterize the banana trunk-activated carbon through methylene blue dye adsorption property. The H3PO4 chemical activating agent was used to produce activated carbons from the banana trunk. A small rotatable central composite design of response surface methodology was adopted to prepare chemically (H3PO4) activated carbon from banana trunk. Three operating variables such as activation time (50-120 min), activation temperature (450-850 °C), and activating agent concentration (1.5-7.0 mol/L) play a significant role in the adsorption capacities ( q) of activated carbons against methylene blue dye. The results implied that the maximum adsorption capacity of fixed dosage (4.0 g/L) banana trunk-activated carbon was achieved at the activation time of 51 min, the activation temperature of 774 °C, and H3PO4 concentration of 5.09 mol/L. At optimum conditions of preparation, the obtained banana trunk-activated carbon has adsorption capacity 64.66 mg/g against methylene blue. Among the prepared activated carbons run number 3 (prepared with central values of the operating variables) was characterized through Fourier transform infrared spectroscopy, field emission scanning microscopy, and powder X-ray diffraction.

Comparison of catalytic activities for photocatalytic and sonocatalytic degradation of organic dye in the presence of ternary Fe{sub 3}O{sub 4}/ZnO/CuO magnetic heteregenous nanocatalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taufik, Ardiansyah; Saleh, Rosari, E-mail: rosari.saleh@gmail.com, E-mail: rosari.saleh@ui.ac.id; Integrated Laboratory of Energy and Environment, Fakultas MIPA-Universitas Indonesia, 16424 Depok

2016-04-19

The Fe{sub 3}O{sub 4}/ZnO/CuO nanocatalyst with various CuO loading were synthesized by sol-gel method and were characterized by powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV-Vis spectroscopy, and vibrating sample magnetometry. The findings demonstrate that all samples exhibit ferromagnetic behavior at room temperatureand containa well-crystalline ternary oxide nanocatalyst. Methylene blue was taken as the model of organic dye to evaluate its photocatalytic and sonocatalytic degradation in the presence of Fe{sub 3}O{sub 4}/ZnO/CuO nanocatalyst. The observed degradation activity indicate that the order of degradation of methylene blue issonocatalysis> photocatalysis. Fe{sub 3}O{sub 4}/ZnO/CuO nanocatalyst with the lowest CuOmore » loading exhibit the highest rate of degradation of methylene blue during the sono- and photocatalytic processes. The experimental data shows that holes are the predominant oxidative species involved in the sono- and photodegradation of methylene blue.« less

Simplified Method for Preparing Methylene-Blue-Sensitized Dichromated Gelatin

NASA Astrophysics Data System (ADS)

Kurokawa, Kazumasa; Koike, Satoshi; Namba, Sinji; Mizuno, Toru; Kubota, Toshihiro

1998-05-01

Methylene-blue-sensitized dichromated gelatin (MBDCG) is a suitable material for recording full-color holograms in a single layer. However, a drying process in an ammonia atmosphere is necessary to prepare the MBDCG plate. This process is time-consuming and unstable. A simplified method for preparing the MBDCG plate is presented in which the MBDCG can be dried without ammonia. Elimination of the drying process is possible when the methylene blue in MBDCG does not separate. This is achieved by a decrease in the concentration of dichromate in the photosensitized solution and the addition of an ammonia solution to the photosensitized solution. Last, the gelatin is allowed to gel. A Lippmann color hologram grating with a diffraction efficiency of more than 80% is obtained by use of this MBDCG.

A simple method to prepare magnetic modified beer yeast and its application for cationic dye adsorption.

PubMed

Yu, Jun-Xia; Wang, Li-Yan; Chi, Ru-An; Zhang, Yue-Fei; Xu, Zhi-Gao; Guo, Jia

2013-01-01

The purpose of this research is to use a simple method to prepare magnetic modified biomass with good adsorption performances for cationic ions. The magnetic modified biomass was prepared by two steps: (1) preparation of pyromellitic dianhydride (PMDA) modified biomass in N, N-dimethylacetamide solution and (2) preparation of magnetic PMDA modified biomass by a situ co-precipitation method under the assistance of ultrasound irradiation in ammonia water. The adsorption potential of the as-prepared magnetic modified biomass was analyzed by using cationic dyes: methylene blue and basic magenta as model dyes. Optical micrograph and x-ray diffraction analyses showed that Fe(3)O(4) particles were precipitated on the modified biomass surface. The as-prepared biosorbent could be recycled easily by using an applied magnetic field. Titration analysis showed that the total concentration of the functional groups on the magnetic PMDA modified biomass was calculated to be 0.75 mmol g(-1) by using the first derivative method. The adsorption capacities (q(m)) of the magnetic PMDA modified biomass for methylene blue and basic magenta were 609.0 and 520.9 mg g(-1), respectively, according to the Langmuir equation. Kinetics experiment showed that adsorption could be completed within 150 min for both dyes. The desorption experiment showed that the magnetic sorbent could be used repeatedly after regeneration. The as-prepared magnetic modified sorbent had a potential in the dyeing industry wastewater treatment.

Sol–gel synthesis of SnO{sub 2}–MgO nanoparticles and their photocatalytic activity towards methylene blue degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayal, Nisha; Jeevanandam, P., E-mail: jeevafcy@iitr.ernet.in

2013-10-15

Graphical abstract: - Highlights: • A simple sol–gel method for the synthesis of SnO{sub 2}–MgO nanoparticles is reported. • Band gap of SnO{sub 2} can be tuned by varying the magnesium content in SnO{sub 2}–MgO. • SnO{sub 2}–MgO shows good photocatalytic activity towards degradation of methylene blue. - Abstract: SnO{sub 2}–MgO mixed metal oxide nanoparticles were prepared by a simple sol–gel method. The nanoparticles were characterized by power X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy. The XRD results indicate the formation of mixed metal oxide nanoparticles and alsomore » a decrease of SnO{sub 2} crystallite size in the mixed metal oxide nanoparticles with increasing magnesium oxide content. The reflectance spectroscopy results show a blue shift of the band gap of SnO{sub 2} in the mixed metal oxide nanoparticles. The photocatalytic activity of the SnO{sub 2}–MgO nanoparticles was tested using the photodegradation of aqueous methylene blue in the presence of sunlight. The results indicate that the mixed metal oxide nanoparticles possess higher efficiency for the photodegradation of methylene blue compared to pure SnO{sub 2} nanoparticles.« less

A Universally Applicable and Rapid Method for Measuring the Growth of Streptomyces and Other Filamentous Microorganisms by Methylene Blue Adsorption-Desorption

PubMed Central

Fischer, Marco

2013-01-01

Quantitative assessment of growth of filamentous microorganisms, such as streptomycetes, is generally restricted to determination of dry weight. Here, we describe a straightforward methylene blue-based sorption assay to monitor microbial growth quantitatively, simply, and rapidly. The assay is equally applicable to unicellular and filamentous bacterial and eukaryotic microorganisms. PMID:23666340

Photocatalytic degradation of methylene blue and inactivation of gram-negative bacteria by TiO2 nanoparticles in aqueous suspension

USDA-ARS?s Scientific Manuscript database

The photocatalytic degradation of methylene blue (MB) and inactivation of Gram-negative bacteria E. coli K12 and P. aeruginosa by TiO2 nanoparticles in aqueous suspension were studied. TiO2 resulted in significant reduction in MB absorption and a shift of MB absorption peak from 664 nm to 658 nm aft...

Methylene Blue-Loaded Dissolving Microneedles: Potential Use in Photodynamic Antimicrobial Chemotherapy of Infected Wounds

PubMed Central

Caffarel-Salvador, Ester; Kearney, Mary-Carmel; Mairs, Rachel; Gallo, Luigi; Stewart, Sarah A.; Brady, Aaron J.; Donnelly, Ryan F.

2015-01-01

Photodynamic therapy involves delivery of a photosensitising drug that is activated by light of a specific wavelength, resulting in generation of highly reactive radicals. This activated species can cause destruction of targeted cells. Application of this process for treatment of microbial infections has been termed “photodynamic antimicrobial chemotherapy” (PACT). In the treatment of chronic wounds, the delivery of photosensitising agents is often impeded by the presence of a thick hyperkeratotic/necrotic tissue layer, reducing their therapeutic efficacy. Microneedles (MNs) are an emerging drug delivery technology that have been demonstrated to successfully penetrate the outer layers of the skin, whilst minimising damage to skin barrier function. Delivering photosensitising drugs using this platform has been demonstrated to have several advantages over conventional photodynamic therapy, such as, painless application, reduced erythema, enhanced cosmetic results and improved intradermal delivery. The aim of this study was to physically characterise dissolving MNs loaded with the photosensitising agent, methylene blue and assess their photodynamic antimicrobial activity. Dissolving MNs were fabricated from aqueous blends of Gantrez® AN-139 co-polymer containing varying loadings of methylene blue. A height reduction of 29.8% was observed for MNs prepared from blends containing 0.5% w/w methylene blue following application of a total force of 70.56 N/array. A previously validated insertion test was used to assess the effect of drug loading on MN insertion into a wound model. Staphylococcus aureus, Escherichia coli and Candida albicans biofilms were incubated with various methylene blue concentrations within the range delivered by MNs in vitro (0.1–2.5 mg/mL) and either irradiated at 635 nm using a Paterson Lamp or subjected to a dark period. Microbial susceptibility to PACT was determined by assessing the total viable count. Kill rates of >96%, were achieved for S. aureus and >99% for E. coli and C. albicans with the combination of PACT and methylene blue concentrations between 0.1 and 2.5 mg/mL. A reduction in the colony count was also observed when incorporating the photosensitiser without irradiation, this reduction was more notable in S. aureus and E. coli strains than in C. albicans. PMID:26426040

Uniform Cu{sub 2}Cl(OH){sub 3} hierarchical microspheres: A novel adsorbent for methylene blue adsorptive removal from aqueous solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Wei; Gao, Pin; Xie, Jimin, E-mail: xiejm391@sohu.com

2013-08-15

Using the solution phase method without any surfactants or templates, the hierarchical of Cu{sub 2}Cl(OH){sub 3} microspheres were synthesized by freeze drying. The size and surface area of the microspheres are ca. 1–2 µm and 76.61 m{sup 2} g{sup −1}, respectively. A possible formation mechanism is presented based on the experimental results. Methylene blue was chosen to investigate the adsorption capacity of the as-prepared adsorbent. The effects of various experimental parameters, such as pH, initial dye concentration, and contact time were investigated. The results showed that the dye removal increased with the increasing in the initial concentration of the dyemore » and also increased in the amount of microspheres used and initial pH. Adsorption data fitted well with the Freundlich adsorption isotherm. The thermodynamic analysis presented the exothermic, spontaneous and more ordered arrangement process. The microspheres could be employed effective for removal of dyes from aqueous solution. - Graphical abstract: The single-crystalline hierarchical Cu{sub 2}Cl(OH){sub 3} spheres can be prepared for the first time by using a template-free process through freeze-drying. Meanwhile, the hierarchical spheres exhibited high adsorption capacity to methylene blue. Display Omitted - Highlights: • Cu{sub 2}Cl(OH){sub 3} microspheres were successfully synthesized through a freeze drying process. • A possible formation mechanism of hierarchical microspheres was presented. • The Cu{sub 2}Cl(OH){sub 3} microspheres have high methylene blue adsorption capacity. • Methylene blue adsorption is a spontaneous and exothermic process. • The adsorption mechanism of microspheres onto dye was proposed in detail.« less

Preoperative Pulmonary Nodule Localization: A Comparison of Methylene Blue and Hookwire Techniques.

PubMed

Kleedehn, Mark; Kim, David H; Lee, Fred T; Lubner, Meghan G; Robbins, Jessica B; Ziemlewicz, Timothy J; Hinshaw, J Louis

2016-12-01

Small pulmonary nodules are often difficult to identify during thoracoscopic resection, and preoperative CT-guided localization performed using either hookwire placement or methylene blue injection can be helpful. The purpose of this study is to compare the localization success and complication rates of these two techniques. One hundred two consecutive patients who underwent a total of 109 localization procedures performed with CT fluoroscopic guidance were analyzed. The procedures included 52 hookwire insertions and 57 methylene blue injections. The localization success and complication rates associated with the two groups were compared. All nodules in both groups were identified intraoperatively, except for those in two patients in the hookwire group who did not proceed to undergo same-day surgery, including one with a massive systemic air embolus that resulted in death. Hookwires were dislodged in seven of 52 cases (13%), but the surgeons were still able to locate the nodules through visualization of the parenchymal puncture sites. The total number of complications was higher in the hookwire insertion group than in the methylene blue injection group, but this trend was not statistically significant, with all types of complications occurring in 28 cases (54%) versus 26 cases (46%) (p = 0.45), major complications noted in four cases (8%) versus one case (2%) (p = 0.19), pneumothorax observed in 20 cases (38%) versus 14 cases (25%) (p = 0.15), and perilesional hemorrhage occurring in six cases (12%) versus two cases (4%) (p = 0.15), respectively. The present study suggests that methylene blue injection and hookwire insertion are statistically equivalent for preoperative pulmonary nodule localization; however, seven of 52 hookwires dislodged, and trends toward more frequent and severe complications were noted in the hookwire insertion group.

Methylene blue intra-arterial staining of resected colorectal cancer specimens improves accuracy of nodal staging: A randomized controlled trial.

PubMed

Reima, H; Saar, H; Innos, K; Soplepmann, J

2016-11-01

Metastatic involvement of regional lymph nodes is a major prognostic factor of colorectal cancer, which influences also its treatment strategy. International consensus foresees retrieval of ≥12 lymph nodes from colorectal specimens. The aim of the study was to assess the effect of intra-arterial staining of colorectal specimens with methylene blue on lymph node harvest. A total of 266 radically operated colorectal cancer patients were randomized into the methylene blue staining and non-staining groups. In the staining group, methylene blue solution was injected into the colorectal specimen's artery after its removal. The specimens were analysed for lymph node count, diameter and metastatic involvement. The median number of lymph nodes was higher in the staining group, 27 (95% CI 23-31%), compared with the control group, 16 (95% CI 14-19, p < 0.001). The number of examined lymph-nodes was ≥12 in 86% of the cases in the staining group and in 69% of the cases in the control group (p = 0.001). In the staining group more small-diameter (≤4 mm) lymph nodes were examined (median number 20.5 vs. 10, p < 0.001). The proportion of patients with metatatic lymph nodes was 42% in the staining group and 43% in the control group (NS). Methylene blue staining improves significantly staging accuracy through finding more small-diameter lymph nodes. It enables to detect ≥12 lymph nodes in the majority of cases. We recommend routine use of this technique in all colorectal resections with curative intent. Copyright © 2016 Elsevier Ltd, BASO ~ the Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Spectrophotometric investigation of the hetero-association of Caffeine and thiazine dye in aqueous solution

NASA Astrophysics Data System (ADS)

Bolotin, P. A.; Baranovsky, S. F.; Evstigneev, M. P.

2006-06-01

The self-association of thiazine dye, Methylene Blue (MB), and its hetero-association with Caffeine (CAF), were studied in aqueous solution by means of spectrophotometry in the visible range of spectrum. Concentration and temperature dependences of molar absorption of the interacting molecules were used to analyse dynamic equilibrium in solution in terms of two-component model of molecular hetero-association. The magnitudes of equilibrium dimerization and hetero-association constants as well as thermodynamic parameters, enthalpy and entropy, were determined. The calculation of the fraction of different types of associates in the mixed solution, containing Methylene Blue and Caffeine, was done. It was concluded that the hetero-association of Methylene Blue and Caffeine molecules results in lower effective concentration of the dye in solution, which may account for the alteration of its biological activity.

Low-temperature synthesis and investigations on photocatalytic activity of nanoparticles BiFeO3 for methylene blue and methylene orange degradation and some toxic organic compounds

NASA Astrophysics Data System (ADS)

Nhiem Dao, Ngoc; Luu, Minh Dai; Chuc Pham, Ngoc; Dung Doan, Trung; Nguyen, Thi Ha Chi; Bac Nguyen, Quang; Lim Duong, Thi

2016-12-01

The photocatalytic BiFeO3 perovskite nanoparticles were fabricated by gel combustion method using polyvinyl alcohol and corresponding metal nitrate precursors under the optimum mild conditions such as pH 2, gel formation temperature of 80 °C, metal/polyvinyl alcohol molar ratio of 1/3, metal molar ratio Bi/Fe of 1/1 and calcination temperature at 500 °C for 2 h. The prepared sample was characterized by x-ray diffraction, field scanning electron microscopy, transmission electron microscopy, Brunauer-Emmetl-Teller nitrogen adsorption method at 77 K, energy dispersive x-ray spectroscopy, ultraviolet-visible light spectrophotometry, and thermal analysis. The effects of molar ratios of starting material and calcination temperature on phase formation and morphology were investigated. The degradation of methylene blue, methylene orange and some toxic organic compounds such as phenol and diazinon under visible light irradiation by photocatalytic BiFeO3 nanoparticles were evaluated at different parameters and conditions such as the light intensity determined from the light source to the measured sample, the addition H2O2, reaction time and the regeneration performance. Obtained results showed that the synthesized perovskite BiFeO3 nanoparticles for the optimized sample have a size smaller than 50 nm and the high mean surface area of 50 m2 g-1. Degradation efficiency was almost 90.0% for methylene blue and 80.0% for methylene orange with added H2O2 after 30 min of reaction. After the 3rd time of regeneration, the BiFeO3 nanoparticles still have 92.8% of the degradation performance for removing methylene blue. Phenol and diazinon toxic compound were degraded with the performance of 92.42% and 85.7%, respectively, for 150 min

The feasibility of using methylene blue sensitized polyvinylalcohol film as a linear polarizer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jyothilakshmi, K.; Anju, K. S.; Arathy, K.

2014-01-28

Linear light polarizing films selectively transmit radiations vibrating along an electromagnetic radiation vector and selectively absorb radiations vibrating along a second electromagnetic radiation vector. It happens according to the anisotropy of the film . In the present study the polarization effects of methylene blue sensitized polyvinyl alcohol is investigated. The polarization effects on the dye concentration, heating and stretching of film also are evaluated.

New observations on endometrial physiology after transcervical injection of methylene blue dye.

PubMed

Marconi, Guillermo; Vilela, Martín; Quintana, Ramiro; Diradourián, Marco; Young, Edgardo; Sueldo, Carlos

2004-12-01

We describe the in vivo features of endometrium stained with methylene blue dye and observed via microhysteroscopy, showing the patterns of endometrial glands and superficial cell changes during the midproliferative, periovulatory, and midluteal phases. These preliminary observations have allowed us to identify a series of changes occurring in the different phases of the ovulatory cycle of potential value in reproductive medicine for specific groups of infertile patients.

Visible Light-Induced Degradation of Methylene Blue in the Presence of Photocatalytic ZnS and CdS Nanoparticles

PubMed Central

Soltani, Nayereh; Saion, Elias; Hussein, Mohd Zobir; Erfani, Maryam; Abedini, Alam; Bahmanrokh, Ghazaleh; Navasery, Manizheh; Vaziri, Parisa

2012-01-01

ZnS and CdS nanoparticles were prepared by a simple microwave irradiation method under mild conditions. The obtained nanoparticles were characterized by XRD, TEM and EDX. The results indicated that high purity of nanosized ZnS and CdS was successfully obtained with cubic and hexagonal crystalline structures, respectively. The band gap energies of ZnS and CdS nanoparticles were estimated using UV-visible absorption spectra to be about 4.22 and 2.64 eV, respectively. Photocatalytic degradation of methylene blue was carried out using physical mixtures of ZnS and CdS nanoparticles under a 500-W halogen lamp of visible light irradiation. The residual concentration of methylene blue solution was monitored using UV-visible absorption spectrometry. From the study of the variation in composition of ZnS:CdS, a composition of 1:4 (by weight) was found to be very efficient for degradation of methylene blue. In this case the degradation efficiency of the photocatalyst nanoparticles after 6 h irradiation time was about 73% with a reaction rate of 3.61 × 10−3 min−1. Higher degradation efficiency and reaction rate were achieved by increasing the amount of photocatalyst and initial pH of the solution. PMID:23202896

Investigation of in vivo toxicity of hydroxylamine sulfate and the efficiency of intoxication treatment by α-tocopherol acetate and methylene blue.

PubMed

Prodanchuk, Mykola G; Tsatsakis, Aristidis M; Prodanchuk, Georgiy M; Tsakalof, Andreas K

2013-11-01

Investigation of hydroxylamine sulfate toxicity mechanism in vivo and estimation of α-tocopherol acetate and methylene blue efficiency in poisoning treatments. In vivo experiments were conducted on 102 Wistar Han rats. The experiments investigated the hematotoxic and oxidative stress effects of hydroxylamine sulfate in acute and subacute toxicity treatment of animals. Electron Spin Resonance was used for quantitative determination of blood and liver tissue parameters alterations after intoxication. The osmotic fragility of erythrocytes, lipid peroxidation intensity and level of SH-groups in liver of rats were determined by established biochemical assays. Hydroxylamine sulfate cause an acute hematotoxicity and oxidative stress in vivo as demonstrated by the appearance of free oxidized iron in blood, reduced glutathione content and increased lipid peroxidation in liver. The experimental studies showed the formation of Hb-NO, MetHb in erythrocytes and as well of stable complex of reduced iron (Fe(2+)) with hydroxylamine sulfate. Methylene blue treatment does not reduce the Hb-NO or MetHb levels in intoxicated animals while administration of α-tocopherol acetate reduces substantially lipid peroxidation. Oxidative stress is a key mechanism of acute hematotoxicity caused by hydroxylamine sulfate. Methylene blue is not suitable antidote in case of hydroxylamine intoxication. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methylene blue dyeing of cellular nuclei during salpingoscopy, a new in-vivo method to evaluate vitality of tubal epithelium.

PubMed

Marconi, G; Quintana, R

1998-12-01

The Fallopian tube can be damaged by different noxious substances that may change cellular ultrastructure and function. Alteration of the cell membrane allows the passage of certain aniline dyes, which can stain the nucleus. A total of 310 Fallopian tubes from 163 patients who underwent a surgical or diagnostic laparoscopy during fertility studies was analysed by salpingoscopy. Cellular nuclei were stained by injection of 20 ml of a 10% solution of methylene blue in saline solution (NaCl 10%) through the cervical cannula prior to salpingoscopy. Evaluation of nuclear staining with methylene blue, adhesions, vascular alterations, and the flattening of folds in relation to pregnancy outcome was undertaken. Quantification of salpingoscopic findings was carried out according to a score. Flattening of folds and vascular alterations showed no difference in the pregnant and non-pregnant groups. On the other hand, adhesions and nuclear dyeing were significantly greater in the non-pregnant group (adhesions 13.6 versus 26.8%, P < 0.004, and nuclear dyeing: 25 versus 41.7%, P < 0.009, pregnant versus non-pregnant). Methylene blue dye is a new tool to evaluate in vivo cyto-histological tubal damage, and is a useful and simple method to provide a prognosis of salpingean function.

EUS-guided methylene blue cholangiopancreatography for benign biliopancreatic diseases after failed ERCP.

PubMed

Consiglieri, Claudia F; Gornals, Joan B; Albines, Gino; De-la-Hera, Meritxell; Secanella, Lluis; Pelaez, Nuria; Busquets, Juli

2016-07-01

When ERCP fails, EUS-guided interventional techniques may be an alternative. The aim of this study was to evaluate the general outcomes and safety of EUS-guided methylene blue cholangiopancreatography in patients with failed ERCP in benign biliopancreatic diseases. Patients with benign biliopancreatic diseases and failed ERCP were included. EUS-guided cholangiopancreatography plus injection of methylene blue was performed, and then ERCP using coloring agent flow as an indicator of papilla orifice was performed. Procedures were prospectively collected in this observational, single-center study. Technical success, clinical success, and adverse events were analyzed retrospectively. Eleven patients were included (10 choledocholithiasis, 1 pancreatic stricture). The main reason for failed ERCP was an unidentifiable papilla. EUS-guided ductal access with cholangiopancreatography and papilla orifice identification was obtained in all cases. Technical success and clinical success rates of 91% were achieved, with successful biliopancreatic drainage in 10 patients. Adverse events included 1 peripancreatic abscess attributed to a precut, which was successfully treated. No adverse events were related to the first EUS-guided stage. EUS-guided cholangiopancreatography with methylene blue injection seems to be a feasible and helpful technique for treatment in patients with benign biliopancreatic diseases with previous failed ERCP because of an undetectable papilla. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Efficacy and safety of primaquine and methylene blue for prevention of Plasmodium falciparum transmission in Mali: a phase 2, single-blind, randomised controlled trial.

PubMed

Dicko, Alassane; Roh, Michelle E; Diawara, Halimatou; Mahamar, Almahamoudou; Soumare, Harouna M; Lanke, Kjerstin; Bradley, John; Sanogo, Koualy; Kone, Daouda T; Diarra, Kalifa; Keita, Sekouba; Issiaka, Djibrilla; Traore, Sekou F; McCulloch, Charles; Stone, Will J R; Hwang, Jimee; Müller, Olaf; Brown, Joelle M; Srinivasan, Vinay; Drakeley, Chris; Gosling, Roly; Chen, Ingrid; Bousema, Teun

2018-06-01

Primaquine and methylene blue are gametocytocidal compounds that could prevent Plasmodium falciparum transmission to mosquitoes. We aimed to assess the efficacy and safety of primaquine and methylene blue in preventing human to mosquito transmission of P falciparum among glucose-6-phosphate dehydrogenase (G6PD)-normal, gametocytaemic male participants. This was a phase 2, single-blind, randomised controlled trial done at the Clinical Research Centre of the Malaria Research and Training Centre (MRTC) of the University of Bamako (Bamako, Mali). We enrolled male participants aged 5-50 years with asymptomatic P falciparum malaria. G6PD-normal participants with gametocytes detected by blood smear were randomised 1:1:1:1 in block sizes of eight, using a sealed-envelope design, to receive either sulfadoxine-pyrimethamine and amodiaquine, sulfadoxine-pyrimethamine and amodiaquine plus a single dose of 0·25 mg/kg primaquine, dihydroartemisinin-piperaquine, or dihydroartemisinin-piperaquine plus 15 mg/kg per day methylene blue for 3 days. Laboratory staff, investigators, and insectary technicians were masked to the treatment group and gametocyte density of study participants. The study pharmacist and treating physician were not masked. Participants could request unmasking. The primary efficacy endpoint, analysed in all infected patients with at least one infectivity measure before and after treatment, was median within-person percentage change in mosquito infectivity 2 and 7 days after treatment, assessed by membrane feeding. This study is registered with ClinicalTrials.gov, number NCT02831023. Between June 27, 2016, and Nov 1, 2016, 80 participants were enrolled and assigned to the sulfadoxine-pyrimethamine and amodiaquine (n=20), sulfadoxine-pyrimethamine and amodiaquine plus primaquine (n=20), dihydroartemisinin-piperaquine (n=20), or dihydroartemisinin-piperaquine plus methylene blue (n=20) groups. Among participants infectious at baseline (54 [68%] of 80), those in the sulfadoxine-pyrimethamine and amodiaquine plus primaquine group (n=19) had a median 100% (IQR 100 to 100) within-person reduction in mosquito infectivity on day 2, a larger reduction than was noted with sulfadoxine-pyrimethamine and amodiaquine alone (n=12; -10·2%, IQR -143·9 to 56·6; p<0·0001). The dihydroartemisinin-piperaquine plus methylene blue (n=11) group had a median 100% (IQR 100 to 100) within-person reduction in mosquito infectivity on day 2, a larger reduction than was noted with dihydroartemisinin-piperaquine alone (n=12; -6·0%, IQR -126·1 to 86·9; p<0·0001). Haemoglobin changes were similar between gametocytocidal arms and their respective controls. After exclusion of blue urine, adverse events were similar across all groups (59 [74%] of 80 participants had 162 adverse events overall, 145 [90%] of which were mild). Adding a single dose of 0·25 mg/kg primaquine to sulfadoxine-pyrimethamine and amodiaquine or 3 days of 15 mg/kg per day methylene blue to dihydroartemisinin-piperaquine was highly efficacious for preventing P falciparum transmission. Both primaquine and methylene blue were well tolerated. Bill & Melinda Gates Foundation, European Research Council. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Diffusion in the Formation of Photopolymer Holograms

DTIC Science & Technology

1992-04-01

based on the reactions of acrylic acid and related compounds that can be dye-sensitized to polymerize under the influence of visible light. 1. Acrylic...rates in what is known as the sector method [36]. The photopolymerizable system is exposed to light of intensity I through a 50% duty cycle rotating...such as methylene blue, with a sulfinic compound [53]. Methylene blue exists as a positive ion in solution; its narrow absorption band peaks in the

Modified pineapple peel cellulose hydrogels embedded with sepia ink for effective removal of methylene blue.

PubMed

Dai, Hongjie; Huang, Huihua

2016-09-05

Novel composite hydrogels based on pineapple peel cellulose and sepia ink were synthesized by homogeneous acetylation of cellulose in ionic liquid 1-butyl-3-methylimidazolium chloride. The structure and morphology of the prepared hydrogels were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction, thermogravimetry and differential scanning calorimetry. The effects of acetylation time, acetylation temperature, molar ratio of acetic anhydride/anhydroglucose unit and the additive amount of sepia ink on methylene blue adsorption capacity of the hydrogels embedded with sepia ink were also investigated. Methylene blue adsorption of the hydrogels followed pseudo-second-order kinetic model and sepia ink improved adsorption capacity significantly. The adsorption capacity at equilibrium was increased from 53.72 to 138.25mg/g when the additive amount of sepia ink of the hydrogels was 10%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Photodynamic therapy for endodontic disinfection.

PubMed

Soukos, Nikolaos S; Chen, Peter Shih-Yao; Morris, Jason T; Ruggiero, Karriann; Abernethy, Abraham D; Som, Sovanda; Foschi, Federico; Doucette, Stephanie; Bammann, Lili Luschke; Fontana, Carla Raquel; Doukas, Apostolos G; Stashenko, Philip P

2006-10-01

The aims of this study were to investigate the effects of photodynamic therapy (PDT) on endodontic pathogens in planktonic phase as well as on Enterococcus faecalis biofilms in experimentally infected root canals of extracted teeth. Strains of microorganisms were sensitized with methylene blue (25 microg/ml) for 5 minutes followed by exposure to red light of 665 nm with an energy fluence of 30 J/cm2. Methylene blue fully eliminated all bacterial species with the exception of E. faecalis (53% killing). The same concentration of methylene blue in combination with red light (222 J/cm2) was able to eliminate 97% of E. faecalis biofilm bacteria in root canals using an optical fiber with multiple cylindrical diffusers that uniformly distributed light at 360 degrees. We conclude that PDT may be developed as an adjunctive procedure to kill residual bacteria in the root canal system after standard endodontic treatment.

Novelties of combustion synthesized titania ultrafiltration membrane in efficient removal of methylene blue dye from aqueous effluent.

PubMed

Doke, Suresh M; Yadav, Ganapati D

2014-12-01

In this study, titania nanoparticles were synthesized by combustion and used to make ultrafiltration membrane. Characteristics of titania membranes such as textural evaluation, surface morphology, pure water permeability and protein rejection were investigated. Titania membrane sintered at 450 °C showed pure water permeability 11 × 10−2 L h−1 m−2 kPa−1 and 76% protein rejection. The membrane presented good water flux and retention properties with regards to protein and methylene blue dye. Ultrafiltration process was operated at lower pressure (100 kPa) and showed 99% removal of methylene blue using adsorptive micellar flocculation at sodium dodecyl sulfate concentration below its critical micellar concentration. Ferric chloride was used as the coagulant. The method of making titania membrane and its use are new. These studies can be extended to other dyes and pollutants.

Guiding intramuscular diaphragm injections using real-time ultrasound and electromyography.

PubMed

Sarwal, Aarti; Cartwright, Michael S; Mitchell, Erin; Williams, Koudy; Walker, Francis O; Childers, Martin K

2015-02-01

We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography (EMG) needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical EMG of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. © 2014 Wiley Periodicals, Inc.

Guiding Intramuscular Diaphragm Injections Using Real-time Ultrasound & Electromyography

PubMed Central

Sarwal, Aarti; Cartwright, Michael S.; Mitchell, Erin; Williams, Koudy; Walker, Francis O.; Childers, Martin K.

2014-01-01

Introduction We describe a unique method that combines ultrasound and electromyography to guide intramuscular diaphragm injections in anesthetized large animals. Methods Ultrasound was used to visualize the diaphragm on each side of spontaneously breathing, anesthetized beagle dogs and cynomolgus macaques. An electromyography needle was introduced and directed by ultrasound to confirm that the needle entered the muscular portion of the diaphragm, and methylene blue was injected. Injection accuracy was confirmed upon necropsy by tracking the spread of methylene blue. Results All methylene blue injections were confirmed to have been placed appropriately into the diaphragm. Conclusions This study demonstrates the feasibility and accuracy of using ultrasound and EMG to guide injections and to reduce complications associated with conventional blind techniques. Ultrasound guidance can be used for clinical electromyography of the diaphragm. Future applications may include targeted diaphragm injections with gene replacement therapy in neuromuscular diseases. PMID:25354257

An introduction to photocatalysis through methylene blue photodegradation

NASA Astrophysics Data System (ADS)

Petit, Matthieu; Michez, Lisa; Raimundo, Jean-Manuel; Malinowski, Tuhiti; Dumas, Philippe

2016-11-01

We described a simple experimental set-up for lab work on the photocatalytic degradation of methylene blue by TiO2 nanoparticles. The photocatalysis process can be used for many applications. Treatments for diluted wastewater industries, air purifying in underground car parks, and preventing fouling on glass surfaces, are some of the potential applications of this phenomenon. The described experiment is easy to perform and the interpretation can be easily adapted to different levels of students, from high school students demonstrating their interest in sustainable development, to students obtaining a Masters in science departments who want to propose a full explanation for all phenomena of the photocatalytic process. Starting with a description of the experimental set-up, we analysed the photocatalyst nanoparticles and applied the Langmuir-Hinshelwood model to our experimental data. Finally we briefly discussed the respective energetic levels of the photocatalyst semiconductor and methylene blue.

Reaction mechanisms of methylene-blue degradation in three-dimensionally integrated micro-solution plasma

NASA Astrophysics Data System (ADS)

Shirafuji, Tatsuru; Ishida, Yodai; Nomura, Ayano; Hayashi, Yui; Goto, Motonobu

2017-06-01

We have performed matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) on methylene-blue aqueous solutions treated with three-dimensionally integrated micro-solution plasma, in which we have acquired the time evolution of mass spectra as a function of treatment time. The time evolution of mass spectral peak intensities for major detected species has clearly indicated that the parent methylene-blue molecules are degraded through consecutive reactions. The primary reaction is the oxidation of the parent molecules. The oxidized species still have two benzene rings in the parent molecules. The secondary reactions are the separation of the oxidized species and the formation of compounds with one benzene ring. We have also performed the numerical fitting of the time evolution of the mass spectral peak intensities, the results of which have indicated that we must assume additional primary reactions before the primary oxidation for better agreement with experimental results.

Methylene blue, midodrine, and pseudoephedrine: a review of alternative agents for refractory hypotension in the intensive care unit.

PubMed

Van Berkel, Megan A; Fuller, Laura A; Alexandrov, Anne W; Jones, G Morgan

2015-01-01

Hypotensive episodes are common among patients in the intensive care unit and can lead to multiorgan failure if uncontrolled. Fluid administration and continuous infusion of vasoactive agents are frequently used for management of hypotension; however, both therapies may be associated with adverse effects including pulmonary edema and tissue necrosis. In addition, availability of these first-line agents has been impacted by the increasing occurrence of drug shortages. Methylene blue, pseudoephedrine, and midodrine have been considered potential alternatives to standard therapy. These agents may not only be used when first-line agents are unavailable due to shortages, but they may also aid in reducing the cumulative dose of other vasoactive agents used. The purpose of this review was to discuss strategies for the safe and effective use of methylene blue, pseudoephedrine, and midodrine for the treatment of hypotension in the critically ill.

Methylene blue adsorption on graphene oxide/calcium alginate composites.

PubMed

Li, Yanhui; Du, Qiuju; Liu, Tonghao; Sun, Jiankun; Wang, Yonghao; Wu, Shaoling; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

2013-06-05

Graphene oxide has been used as an adsorbent in wastewater treatment. However, the dispersibility in aqueous solution and the biotoxicity to human cells of graphene oxide limits its practical application in environmental protection. In this research, a novel environmental friendly adsorbent, calcium alginate immobilized graphene oxide composites was prepared. The effects of pH, contact time, temperature and dosage on the adsorption properties of methylene blue onto calcium alginate immobilized graphene oxide composites were investigated. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 181.81 mg/g. The pseudo-first order, pseudo-second order, and intraparticle diffusion equation were used to evaluate the kinetic data. Thermodynamic analysis of equilibriums indicated that the adsorption reaction of methylene blue onto calcium alginate immobilized graphene oxide composites was exothermic and spontaneous in nature. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced catalytic activity without the use of an external light source using microwave-synthesized CuO nanopetals

PubMed Central

Bajaj, Sonal; Nayak, Arpan Kumar; Pradhan, Debabrata; Tekade, Pradip

2017-01-01

We report enhanced catalytic activity of CuO nanopetals synthesized by microwave-assisted wet chemical synthesis. The catalytic reaction of CuO nanopetals and H2O2 was studied with the application of external light source and also under dark conditions for the degradation of the hazardous dye methylene blue. The CuO nanopetals showed significant catalytic activity for the fast degradation of methylene blue and rhodamine B (RhB) under dark conditions, without the application of an external light source. This increased catalytic activity was attributed to the co-operative role of H2O2 and the large specific surface area (≈40 m2·g−1) of the nanopetals. We propose a detail mechanism for this fast degradation. A separate study of the effect of different H2O2 concentrations for the degradation of methylene blue under dark conditions is also illustrated. PMID:28685117

Facile synthesis of microporous SiO2/triangular Ag composite nanostructures for photocatalysis

NASA Astrophysics Data System (ADS)

Sirohi, Sidhharth; Singh, Anandpreet; Dagar, Chakit; Saini, Gajender; Pani, Balaram; Nain, Ratyakshi

2017-11-01

In this article, we present a novel fabrication of microporous SiO2/triangular Ag nanoparticles for dye (methylene blue) adsorption and plasmon-mediated degradation. Microporous SiO2 nanoparticles with pore size <2 nm were synthesized using cetyltrimethylammonium bromide as a structure-directing agent and functionalized with APTMS ((3-aminopropyl) trimethoxysilane) to introduce amine groups. Amine-functionalized microporous silica was used for adsorption of triangular silver (Ag) nanoparticles. The synthesized microporous SiO2 nanostructures were investigated for adsorption of different dyes including methylene blue, congo red, direct green 26 and curcumin crystalline. Amine-functionalized microporous SiO2/triangular Ag nanostructures were used for plasmon-mediated photocatalysis of methylene blue. The experimental results revealed that the large surface area of microporous silica facilitated adsorption of dye. Triangular Ag nanoparticles, due to their better charge carrier generation and enhanced surface plasmon resonance, further enhanced the photocatalysis performance.

Photodynamic Inactivation of Acinetobacter baumannii Using Phenothiazinium Dyes: In Vitro and In Vivo Studies

PubMed Central

Ragàs, Xavier; Dai, Tianhong; Tegos, George P.; Agut, Montserrat; Nonell, Santi; Hamblin, Michael R.

2010-01-01

Background and Objective Phenothiazinium dyes have been reported to be effective photosensitizers inactivating a wide range of microorganisms in vitro after illumination with red light. However, their application in vivo has not extensively been explored. This study evaluates the bactericidal activity of phenothiazinium dyes against multidrug-resistant Acinetobacter baumannii both in vitro and in vivo. Study Design/Materials and Methods We report the investigation of toluidine blue O, methylene blue, 1,9-dimethylmethylene blue, and new methylene blue for photodynamic inactivation of multidrug-resistant A. baumannii in vitro. The most effective dye was selected to carry out in vivo studies using third-degree mouse burns infected with a bioluminescent A. baumannii strain, upon irradiation with a 652 nm noncoherent light source. The mice were imaged daily for 2 weeks to observe differences in the bioluminescence–time curve between the photodynamic therapy (PDT)-treated mice in comparison with untreated burns. Results All the dyes were effective in vitro against A. baumannii after 30 J/cm2 irradiation of 635 or 652 nm red light had been delivered, with more effective killing when the dye remained in solution. New methylene blue was the most effective of the four dyes, achieving a 3.2-log reduction of the bacterial luminescence during PDT in vivo after 360 J/cm2 and an 800 μM dye dose. Moreover, a statistically significant reduction of the area under the bioluminescence–time curve of PDT-treated mice was observed showing that the infection did not recur after PDT. Conclusions Phenothiazinium dyes, and especially new methylene blue, are potential photosensitizers for PDT to treat burns infected with multidrug-resistant A. baumannii in vivo. PMID:20583252

Clinical Evaluation and Magnetic Resonance Imaging Assessment of Intradiscal Methylene Blue Injection for the Treatment of Discogenic Low Back Pain.

PubMed

Zhang, XiaoJun; Hao, Jie; Hu, Zhenming; Yang, HaiTao

2016-01-01

Low back pain is a common worldwide health problem and has a significant socioeconomic impact on public health. Internal disc disruption has been considered as the most common cause of low back pain. Various therapies, including interbody fusion, disc replacement, injection therapies, and thermal annular procedures have been utilized for the treatment of discogenic low back pain. Recently, a new method of intradiscal methylene blue injection has been introduced to treat discogenic low back pain, but the clinical outcomes are controversial. To investigate the clinical outcomes and magnetic resonance imaging changes of intradiscal methylene blue injection for the treatment of discogenic low back pain. Observational study. An interventional low back pain management practice in a university hospital. A total of 33 patients were selected to be treated with intradiscal methylene blue injection. The clinical outcomes were evaluated by numeric rating scale and Oswestry Disability Index at pretreatment, one month, 3, 6, and 12 months after treatment. The magnetic resonance imaging changes of involved intervertebral discs were assessed by apparent diffusion coefficient and T2 values at pretreatment, 3, 6, and 12 months after treatment. All of the patients got a follow-up period up to 12 months. The mean numeric rating scale scores at pretreatment, one month, 3, 6, and 12 months after treatment were 6.54, 2.98, 3.23, 3.66, and 4.72, respectively. There was a minimum of 2 points reduction at one month, 3, and 6 months after treatment, but less than 2 points reduction at 12 months. There was at least 50% improvement on the Oswestry Disability Index at one month, 3, and 6 months after treatment, but not at 12 months. The mean apparent diffusion coefficient and T2 value were significantly higher at 6 and12 months after treatment compared to pretreatment, but there was no significant difference between pretreatment and 3 months after treatment. This is an observational study with a relatively small sample size and short-term follow-up. The intradiscal methylene blue injection might be an effective therapy for discogenic low back pain for the short-term and could improve disc degeneration condition to some extent.Key words: Low back pain, discogenic pain, internal disc disruption, provocation discography, methylene blue, intradiscal injection, disc degeneration, magnetic resonance, imaging.

Loading Ag nanoparticles on Cd(II) boron imidazolate framework for photocatalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Min; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002; Zhang, De-Xiang

2016-05-15

An amine-functionalized Cd(II) boron imidazolate framework (BIF-77) with three-dimensional open structure has been successfully synthesized, which can load Ag nanoparticles (NPs) for photocatalytic degradation of methylene blue (MB). - Graphical abstract: An amine-functionalized neutral Cd(II) boron imidazolate framework can load Ag NPs and show excellent photocatalytic degradation behavious for MB. - Highlights: • Amine-functionalization. • Neutral boron imidazolate framework. • Loading Ag nanoparticles (NPs). • Photocatalytic degradation of methylene blue.

Intraoperative use of fibrin glue dyed with methylene blue in surgery for branchial cleft anomalies.

PubMed

Piccioni, Michela; Bottazzoli, Marco; Nassif, Nader; Stefini, Stefania; Nicolai, Piero

2016-09-01

We present a new method of optimizing the results of surgery for branchial cleft anomalies based on the intraoperative injection of fibrin glue combined with methylene blue dye. Retrospective single-center cohort study. The method was applied in 17 patients suffering from branchial anomalies. Six (35.29%) had a preauricular lesion; three (17.65%) had lesions derived from the first arch/pouch/groove (type I), four (23.53%) had lesions derived from the first (type II), one (5.88%) had lesions derived from the second, one (5.88%) had lesions derived from the third, and two (11.76%) had lesions derived from the fourth. The median and mean age at surgery were 10 and 10.6 years, respectively. All patients were followed by periodic clinical and ultrasonographic examination. The combination of fibrin glue with methylene blue facilitated the correct assessment of the extension of the lesions and their intraoperative manipulation. After a mean follow-up of 47.8 months, all patients were free of disease. Intraoperative injection of branchial fistulae and cysts by a mixture of fibrin glue and methylene blue is an effective, easy, and safe tool to track lesions and achieve radical resection. The technique requires a definitive validation on a large cohort with adequate stratification of patients. 4 Laryngoscope, 126:2147-2150, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Quantitative methylene blue decolourisation assays as rapid screening tools for assessing the efficiency of catalytic reactions.

PubMed

Kruid, Jan; Fogel, Ronen; Limson, Janice Leigh

2017-05-01

Identifying the most efficient oxidation process to achieve maximum removal of a target pollutant compound forms the subject of much research. There exists a need to develop rapid screening tools to support research in this area. In this work we report on the development of a quantitative assay as a means for identifying catalysts capable of decolourising methylene blue through the generation of oxidising species from hydrogen peroxide. Here, a previously described methylene blue test strip method was repurposed as a quantitative, aqueous-based spectrophotometric assay. From amongst a selection of metal salts and metallophthalocyanine complexes, monitoring of the decolourisation of the cationic dye methylene blue (via Fenton-like and non-Fenton oxidation reactions) by the assay identified the following to be suitable oxidation catalysts: CuSO 4 (a Fenton-like catalyst), iron(II)phthalocyanine (a non-Fenton oxidation catalyst), as well as manganese(II) phthalocyanine. The applicability of the method was examined for the removal of bisphenol A (BPA), as measured by HPLC, during parallel oxidation experiments. The order of catalytic activity was identified as FePc > MnPc > CuSO 4 for both BPA and MB. The quantitative MB decolourisation assay may offer a rapid method for screening a wide range of potential catalysts for oxidation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of genotoxicity related to oral methylene blue chromoendoscopy.

PubMed

Repici, Alessandro; Ciscato, Camilla; Wallace, Michael; Sharma, Prateek; Anderloni, Andrea; Carrara, Silvia; Di Leo, Milena; Hassan, Cesare

2018-06-15

 An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy.  This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200 mg MB-MMX added to their bowel prep. Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens.  Ten patients were included in the study. The mean expression of γH2AX ± 95 % confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively ( P  = 0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred.  An oral dose of 200 mg of MB-MMX did not result in any detectable DNA damage. © Georg Thieme Verlag KG Stuttgart · New York.

Microwave atmospheric pressure plasma jets for wastewater treatment: Degradation of methylene blue as a model dye.

PubMed

García, María C; Mora, Manuel; Esquivel, Dolores; Foster, John E; Rodero, Antonio; Jiménez-Sanchidrián, César; Romero-Salguero, Francisco J

2017-08-01

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min -1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

The comparison of methylene blue and vitamin E in prevention of abdominal postoperative adhesion formation in rat uterine horn models: Biochemical and histopathologic evaluation.

PubMed

Yildiz, Hamit; Durmus, Ali Said; Simsek, Halil; Yaman, Ihsan

2011-02-01

To compare the effects of vitamin E and 1% methylen blue solutions on prevention of experimentally induced adhesions in rats. Thirty seven female Spraque Dawley rats were randomized into four groups. First group was kept as sham operated group. An adhesion model was constituted on the left uterine horn of the other groups. The lesion areas of rats from the second, the third and the fourth groups were coated with 2 ml 0.9 % saline solution (C group), 10 mg vitamin E (VE group) and 1% methylen blue solutions (MB group), respectively. Histopathologically, adhesion scores, mononuclear cell infiltration, oedema and fibrosis were more prominent in the MB group compared with C and VE groups. There were no significant differences between the groups in tissue glutathione peroxidase (GPx), catalase (CAT) activities and glutation (GSH) level, these parameters were slightly increased in group with VE supplementation though. The administration of VE and MB significantly decreased NO (P<0.01) levels when compared to the C group. The level of malondialdehyde (MDA) in the VE group was significantly lower (P<0.05) than those of the Sh and C groups. Intraperitoneal methylen blue solutions treatments were more effective according to vitamin E in preventing the formation of intra-abdominal adhesion in a rat uterine horn model.

Ag-ligand modified tungstovandates and their efficient catalysis degradation properties for methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Ran; Zhang, Huixia; Liu, Yunping

Two polytungstovandates [Ag(mbpy){sub 2}][Ag{sub 2}(mbpy){sub 3}][VW{sub 5}O{sub 19}]·H{sub 2}O (1) and [Ag(mbpy)]{sub 2}[Ag(mbpy){sub 2}]{sub 4}[VW{sub 12}O{sub 40}] (2) (mbpy =4,4′-dimethyl-2,2′-bipyridyl), had been hydrothermally synthesized and characterized by IR, TG, and single-crystal X-ray diffraction techniques. Single-crystal structural analysis revealed that the polyanionic clusters in two compounds are different: Lindqvist-type in 1 and α-Keggin-type in 2, respectively, while the cationic moieties in them are Ag-mbpy units. The experiments showed that this kind of hybrid crystal materials possesses more efficiently catalytic performance for the degradation of organic dye methylene blue (MB) in water solution under the UV irradiation. The significant degradation rate ofmore » MB can reach 89.9%, 94.9% by crystals 1 and 2 (40 mg) in the course of about 5 min. - Graphical abstract: Two Ag-ligand modified polytungstovandates had been synthesized and characterized, which were active in the catalytic degradation of organic dye methylene blue under the UV irradiation. - Highlights: • Two Ag-ligand modified tungstovandates were synthesized and characterized. • Weak interactions play important roles in constructing crystal frameworks. • Compounds are active to catalyze the degradation of methylene blue.« less

Mechanisms of Alizarin Red S and Methylene blue biosorption onto olive stone by-product: Isotherm study in single and binary systems.

PubMed

Albadarin, Ahmad B; Mangwandi, Chirangano

2015-12-01

The biosorption process of anionic dye Alizarin Red S (ARS) and cationic dye methylene blue (MB) as a function of contact time, initial concentration and solution pH onto olive stone (OS) biomass has been investigated. Equilibrium biosorption isotherms in single and binary systems and kinetics in batch mode were also examined. The kinetic data of the two dyes were better described by the pseudo second-order model. At low concentration, ARS dye appeared to follow a two-step diffusion process, while MB dye followed a three-step diffusion process. The biosorption experimental data for ARS and MB dyes were well suited to the Redlich-Peterson isotherm. The maximum biosorption of ARS dye, qmax = 16.10 mg/g, was obtained at pH 3.28 and the maximum biosorption of MB dye, qmax = 13.20 mg/g, was observed at basic pH values. In the binary system, it was indicated that the MB dye diffuses firstly inside the biosorbent particle and occupies the biosorption sites forming a monodentate complex and then the ARS dye enters and can only bind to untaken sites; forms a tridentate complex with OS active sites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Variations on the "Blue-Bottle" Demonstration Using Food Items That Contain FD&C Blue #1

ERIC Educational Resources Information Center

Staiger, Felicia A.; Peterson, Joshua P.; Campbell, Dean J.

2015-01-01

Erioglaucine dye (FD&C Blue #1) can be used instead of methylene blue in the classic "blue-bottle" demonstration. Food items containing FD&C Blue #1 and reducing species such as sugars can therefore be used at the heart of this demonstration, which simply requires the addition of strong base such as sodium hydroxide lye.

Effect of ultrasonic frequency on degradation of methylene blue in the presence of particle

NASA Astrophysics Data System (ADS)

Kobayashi, Daisuke; Suzuki, Atsushi; Takahashi, Tomoki; Matsumoto, Hideyuki; Kuroda, Chiaki; Otake, Katsuto; Shono, Atsushi

2012-05-01

Techniques for the degradation of hazardous organic compounds have been investigated such as solvent extraction, incineration, chemical dehalogenation and biodegradation, etc. Ultrasound has been found to be an attractive advanced technology for the degradation of hazardous organic compounds in water. In addition, the sonochemical reaction is enhanced by particle addition. However, the enhancement mechanism of particle addition has not been investigated well, because ultrasound enhances not only chemical reaction but also mass transfer. In this study, the degradation process of methylene blue as the model hazardous organic compound by ultrasonic irradiation was investigated. The effects of ultrasonic irradiation condition on degradation rate were investigated. The effect of ultrasonic frequency on improvement of degradation reaction by particle addition was also investigated. In addition, the effects of ultrasonic frequency on ultrasonic power and chemical efficiency were investigated by calorimetry and SE value. The degradation rate constants were estimated from the results of temporal change of the concentration of methylene blue assuming first order kinetics for the decomposition. There was a linear relation in the degradation rate and the ultrasonic power. In addition, the degradation rates at 127 kHz and 490 kHz were much larger than that at 22.8 kHz. The effect of ultrasonic frequency on sonochemical efficiency has been investigated, and the sonochemical effects in the range of frequency of 200 - 500 kHz are 10 times larger than those in the lower or higher frequency regions. Therefore, the degradation rate of methylene blue was considered to estimate using sonochemical efficiency. The degradation process of methylene blue was intensified by particle addition, and the degradation rate increased with increasing amount of particle. On the other hand, the enhancement of degradation rate by particle addition was influenced by both ultrasonic frequency and species of particle. The relationship between particle size and resonance diameter of ultrasound is considered to influence the enhancement of ultrasonic degradation process.

Quantitative evaluation of plasma after methylene blue and white light treatment in four Chinese blood centers.

PubMed

Chunhui, Yang; Guohui, Bian; Hong, Yang; Xiaopu, Xiao; Zherong, Bai; Mingyuan, Wang; Xinsheng, Zhang; Juanjuan, Wang; Changqing, Li; Wuping, Li

2013-12-01

Pathogen reduction technology is an important process in the blood safety system, including solvent/detergent treatment, filtration and methylene blue-photochemical technology (MB-PCT). To investigate the quality of MB-PCT-treated plasma, plasma samples from four Chinese blood centers were analyzed over 12 months of storage to determine the recovery of activities and levels of various plasma proteins. Ten plasma units each from the Suzhou, Yancheng, Chongqing and Shandong blood centers were divided into two aliquots. One was subjected to treatment with one of two methylene blue-photochemical technology instruments and the other was used as control. The treated and untreated sample pairs were stored at -30°C. The recovery rates of coagulation factors, inhibitor proteins, total protein, immunoglobulins, and complement proteins were measured at different time points after storage. The mean recovery of most proteins exceeded 80% after MB treatment. The exceptions were factor XI and fibrinogen, of which only 71.3-74% and 69.0-92.3% were retained during storage. The two equipment types differed in terms of residual MB concentration in the plasma samples (0.18 μM and 0.29 μM, respectively). They had similar protein recovery rates at 0.5 month but differed at later time points. The four blood centers differed significantly with regard to factor II, V, VIII and fibrinogen activities. Only the samples from the Shandong blood center met the methylene blue treated fresh frozen plasma requirement. The major factor that influenced the quality of the MB-FFP samples was the time taken between blood collection and storage. Methylene blue treated plasma showed reduced coagulation factor (CF) activity and protein levels. The MB treatment-induced damage to the proteins was acceptable at the four Chinese blood centers, but the quality of the MB-treated plasma in general was not satisfactory. The main factor affecting plasma quality may be the duration of the collection and processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Computed Tomography-Guided Methylene Blue Labeling Prior to Thoracoscopic Resection of Small Deeply Placed Pulmonary Nodules. Do We Really Need Palpation?

PubMed

Findik, Gokturk; Demiröz, S Mustafa; Apaydın, Selma Mine Kara; Ertürk, Hakan; Biri, Suzan; Incekara, Funda; Aydogdu, Koray; Kaya, Sadi

2017-08-01

Background  Video-assisted thoracic surgery (VATS) is widely used for thoracic surgery operations, and day by day it becomes routine for the excision of undetermined pulmonary nodules. However, it is sometimes hard to reach millimetric nodules through a VATS incision. Therefore, some additional techniques were developed to reach such nodules little in size and which are settled on a challenging localization. In the literature, coils, hook wires, methylene blue, lipidol, and barium staining, and also ultrasound guidance were described for this aim. Herein we discuss our experience with CT-guided methylene blue labeling of small, deeply located pulmonary nodules just before VATS excision. Method  From April 2013 to October 2016, 11 patients with millimetric pulmonary nodules (average 8, 7 mm) were evaluated in our clinic. For all these patients who had strong predisposing factors for malignancy, an 18F-FDG PET-CT scan was also performed. The patients whose nodules were decided to be excised were consulted the radiology clinic. The favorable patients were taken to CT room 2 hours prior to the operation, and CT-guided methylene blue staining were performed under sterile conditions. Results  Mean nodule size of 11 patients was 8.7 mm (6, 2-12). Mean distance from the visceral pleural surface was 12.7 mm (4-29.3). Four of the nodules were located on the left (2 upper lobes, 2 lower lobes), and seven of them were on the right (four lower lobes, two upper lobes, one middle lobe). The maximum standardized uptake values (SUV max) on 18F-FDG PET/CT scan ranged between 0 and 2, 79. Conclusion  CT-guided methylene blue staining of millimetric deeply located pulmonary nodules is a safe and feasible technique that helps surgeon find these undetermined nodules by VATS technique without any need of digital palpation. Georg Thieme Verlag KG Stuttgart · New York.

VATS intraoperative tattooing to facilitate solitary pulmonary nodule resection.

PubMed

Willekes, Lourens; Boutros, Cherif; Goldfarb, Michael A

2008-03-19

Video-assisted thoracic surgery (VATS) has become routine and widely accepted for the removal of solitary pulmonary nodules of unknown etiology. Thoracosopic techniques continue to evolve with better instruments, robotic applications, and increased patient acceptance and awareness. Several techniques have been described to localize peripheral pulmonary nodules, including pre-operative CT-guided tattooing with methylene blue, CT scan guided spiral/hook wire placement, and transthoracic ultrasound. As pulmonary surgeons well know, the lung and visceral pleura may appear featureless on top of a pulmonary nodule. This paper presents a rapid, direct and inexpensive approach to peripheral lung lesion resection by marking the lung parenchyma on top of the nodule using direct methylene blue injection. In two patients with peripherally located lung nodules (n = 3) scheduled for VATS, we used direct methylene blue injection for intraoperative localization of the pulmonary nodule. Our technique was the following: After finger palpation of the lung, a spinal 25 gauge needle was inserted through an existing port and 0.1 ml of methylene blue was used to tattoo the pleura perpendicular to the localized nodule. The methylene blue tattoo immediately marks the lung surface over the nodule. The surgeon avoids repeated finger palpation, while lining up stapler, graspers and camera, because of the visible tattoo. Our technique eliminates regrasping and repalpating the lung once again to identify a non marked lesion. Three lung nodules were resected in two patients. Once each lesion was palpated it was marked, and the area was resected with security of accurate localization. All lung nodules were resected in totality with normal lung parenchymal margins. Our technique added about one minute to the operative time. The two patients were discharged home on the second postoperative day, with no morbidity. VATS with intraoperative tattooing is a safe, easy, and accurate technique to streamline and efficiently resect solitary pulmonary nodules.

Methylene blue MMX® tablets for chromoendoscopy. Bioavailability, colon staining and safety in healthy volunteers undergoing a full colonoscopy.

PubMed

Di Stefano, A F D; Radicioni, M M; Vaccani, A; Fransioli, A; Longo, L; Moro, L; Repici, A

2018-06-01

Methylene blue-MMX® tablets are proposed as an aid for detection and visualisation of adenomas and carcinomas in patients undergoing colonoscopy, by improving their detection rate and highlighting the presence of the intestinal dysplastic lesions. Single total doses of 100 and 200 mg were administered to healthy volunteers undergoing a bowel cleansing preparation and a full colonoscopy to investigate the colonic staining. The pharmacokinetics of methylene blue and the safety after exposure to the tablets were also investigated. With 200 mg, the best staining, assessed as the sum of acceptable and good staining, was achieved in the ascending colon and rectosigmoid (75% subjects each), the transverse and the descending colon (approximately 63% each). Absence of staining or overstaining were reported for no colonic region of interest in any subject. Similar results were observed in the 100 mg dose group. Methylene blue blood concentrations reached a peak (C max ) in a median time (T max ) of 12 h with 100 mg and 16 h with 200 mg. AUC 0-t was 10.7 ± 6.7 μg/mLxh after 100 mg and 25.2 ± 7.4 μg/mLxh after 200 mg. Half-life ranged between 9 and 22 h after the lower dose and between 6 and 26 h after the higher dose. The cumulative excretion was about 28% after 100 mg and about 39% after 200 mg. The overall frequency of adverse events was 39%, but only one was related to the product: abnormal transaminases. The most frequent adverse event was a transient polyuria (17%). One serious adverse event (gastrointestinal haemorrhage) led the subject to study discontinuation and hospitalisation and another subject withdrew the study due to one adverse event (haematemesis). Either event was not related to methylene blue. Copyright © 2017. Published by Elsevier Inc.

The effect of 25% tannic acid on prepared dentin: a scanning electron microscope-methylene blue dye study.

PubMed

Bitter, N C

1990-07-01

The effect on the permeability of prepared dentin treated with 25% tannic acid and 6% citric acid was compared with the untreated dentinal surface. Methylene blue was applied to the dentin surface after treatment to evaluate penetration into dentinal tubules. The tannic acid solution reduced or prevented dye penetration of the dentinal tubules. Citric acid treatment permitted severe penetration. The 25% tannic acid solution removed the smear layer while inhibiting penetration of the dye.

SERS of Methylene Blue induced by plasmonic coupled nanoparticle arrays

NASA Astrophysics Data System (ADS)

Kaydashev, V. E.; Lyanguzov, N. V.; Anokhin, A. S.; Chernishov, A.; Kaidashev, E. M.

2018-04-01

We study the surface enhanced Raman scattering of Methylene Blue (MB) dye molecules induced by large quasihomogeneous arrays of plasmon coupled 5-8 nm Au nanoparticle separated by distances less than 10 nm. Also, the variation of the fluorescence enhancement/SERS properties for as-prepared coupled particles and agglomerated particles obtained upon heat treatment and percolation-like films is analyzed for two measurement protocols, i.e. when measured through the solution and for a monolayer of MB molecules chemisorbed on a surface.

Cultural and morphological properties of the vaccine strain Yersinia pestis EV NIIEG bacteria after photodynamic inactivation

NASA Astrophysics Data System (ADS)

Ulianova, Onega V.; Lyapina, Anna M.; Khizhnyakova, Mariya A.; Laskavy, Vladislav N.; Feodorova, Valentina A.; Ulyanov, Sergey S.

2015-03-01

New method of photoinactivation of plague microbes (bacteria Yersinia pestis) has been suggested. Rate of growth of colonies of Y. pestis EV NIIEG at specific regimes of photo processing have been analyzed. Dependence of growth on exposure time and concentrations of photosensitizer (methylene blue) has been studied. Number of colony forming units of Y. pestis EV NIIEG bacteria as a function of intensity of light and concentration of methylene blue has been scrutinized.

Origin of the blue shift of the CH stretching band for 2-butoxyethanol in water.

PubMed

Katsumoto, Yukiteru; Komatsu, Hiroyuki; Ohno, Keiichi

2006-07-26

The blue shift of the isolated CD stretching band of 2-butoxyethanol (C4E1), which is observed for the aqueous solution during the dilution process, has been investigated by infrared (IR) spectroscopy and quantum chemical calculations. Mono-deuterium-labeled C4E1's were employed to remove the severe overlapping among the CH stretching bands. The isolated CD stretching mode of the alpha-methylene in the butoxy group shows a large blue shift, while those of the beta-methylene and methyl groups are not largely shifted. The spectral simulation results for the C4E1/H2O complexes indicate that the large blue shift of the CD stretching band of the butoxy group arises mainly from the hydration of the ether oxygen atom.

Phosphorus dendrimers and photodynamic therapy. Spectroscopic studies on two dendrimer-photosensitizer complexes: Cationic phosphorus dendrimer with rose bengal and anionic phosphorus dendrimer with methylene blue.

PubMed

Dabrzalska, Monika; Zablocka, Maria; Mignani, Serge; Majoral, Jean Pierre; Klajnert-Maculewicz, Barbara

2015-08-15

Dendrimers due to their unique architecture may play an important role in drug delivery systems including chemotherapy, gene therapy and recently, photodynamic therapy as well. We investigated two dendrimer-photosensitizer systems in context of potential use of these systems in photodynamic therapy. The mixtures of an anionic phosphorus dendrimer of the second generation and methylene blue were studied by UV-vis spectroscopy while that of a cationic phosphorus dendrimer (third generation) and rose bengal were investigated by spectrofluorimetric methods. Spectroscopic analysis of these two systems revealed the formation of dendrimer-photosensitizer complexes via electrostatic interactions as well as π stacking. The stoichiometry of the rose bengal-cationic dendrimer complex was estimated to be 7:1 and 9:1 for the methylene blue-anionic dendrimer complex. The results suggest that these polyanionic or polycationic phosphorus dendrimers can be promising candidates as carriers in photodynamic therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct intraperitoneal resuscitation with lidocaine, methylene blue and pentoxiphylline combination does not decreases inflammation after intestinal ischemia-reperfusion injury in rats.

PubMed

Gandini, Marco; Cerri, Simona; Pregel, Paola; Giusto, Gessica; Vercelli, Cristina; Iussich, Selina; Tursi, Massimiliano; Farca, Anna Maria

2016-05-01

To evaluate the effects of an intraperitoneal solution of methylene blue (MB), lidocaine and pentoxyphylline (PTX) on intestinal ischemic and reperfusion injury. Superior mesenteric artery was isolated and clamped in 36 adult male Sprague Dawley rats. After 60 minutes, clamp was removed and a group received intraperitoneally UNITO solution (PTX 25mg/kg + lidocaine 5mg/kg + MB 2mg/kg), while the other group was treated with warm 0.9% NaCl solution. Rats were euthanized 45 min after drug administration. Lung and bowel were collected for histological evaluation (using Park's score) and determination of myeloperoxidase (MPO) and malondialdehyde (MDA) levels. Control samples showed lymphoplasmocytic infiltrate and crypt necrosis of villi. MPO and MDA measurements shown no differences between treated and control groups. The combination of lidocaine, methylene blue and pentoxyphylline administered intraperitoneally at the studied dose, did not decreased histological lesion scores and biochemical markers levels in intestinal ischemia/reperfusion injury.

Nanoparticle-mediated combination chemotherapy and photodynamic therapy overcomes tumor drug resistance.

PubMed

Khdair, Ayman; Chen, Di; Patil, Yogesh; Ma, Linan; Dou, Q Ping; Shekhar, Malathy P V; Panyam, Jayanth

2010-01-25

Tumor drug resistance significantly limits the success of chemotherapy in the clinic. Tumor cells utilize multiple mechanisms to prevent the accumulation of anticancer drugs at their intracellular site of action. In this study, we investigated the anticancer efficacy of doxorubicin in combination with photodynamic therapy using methylene blue in a drug-resistant mouse tumor model. Surfactant-polymer hybrid nanoparticles formulated using an anionic surfactant, Aerosol-OT (AOT), and a naturally occurring polysaccharide polymer, sodium alginate, were used for synchronized delivery of the two drugs. Balb/c mice bearing syngeneic JC tumors (mammary adenocarcinoma) were used as a drug-resistant tumor model. Nanoparticle-mediated combination therapy significantly inhibited tumor growth and improved animal survival. Nanoparticle-mediated combination treatment resulted in enhanced tumor accumulation of both doxorubicin and methylene blue, significant inhibition of tumor cell proliferation, and increased induction of apoptosis. These data suggest that nanoparticle-mediated combination chemotherapy and photodynamic therapy using doxorubicin and methylene blue has significant therapeutic potential against drug-resistant tumors. Copyright 2009 Elsevier B.V. All rights reserved.

Tubular structured hierarchical mesoporous titania material derived from natural cellulosic substances and application as photocatalyst for degradation of methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Haiqing; Liu, Xiaoyan; Huang, Jianguo, E-mail: jghuang@zju.edu.cn

Graphical abstract: Bio-inspired, tubular structured hierarchical mesoporous titania material with high photocatalytic activity under UV light was fabricated employing natural cellulosic substance (cotton) as hard template and cetyltrimethylammonium bromide (CTAB) surfactant as soft template using a one-pot sol-gel method. Highlights: {yields} Tubular structured mesoporous titania material was fabricated by sol-gel method. {yields} The titania material faithfully recorded the hierarchical structure of the template substrate (cotton). {yields} The titania material exhibited high photocatalytic activity in decomposition of methylene blue. -- Abstract: Bio-inspired, tubular structured hierarchical mesoporous titania material was designed and fabricated employing natural cellulosic substance (cotton) as hard template andmore » cetyltrimethylammonium bromide (CTAB) surfactant as soft template by one-pot sol-gel method. The tubular structured hierarchical mesoporous titania material processes large specific surface area (40.23 m{sup 2}/g) and shows high photocatalytic activity in the photodegradation of methylene blue under UV light irradiation.« less

Photo-, sono- and sonophotocatalytic degradation of methylene blue using Fe3O4/ZrO2 composites catalysts

NASA Astrophysics Data System (ADS)

Kristianto, Y.; Taufik, A.; Saleh, R.

2017-07-01

In the present work, magnetite material Fe3O4/ZrO2 with various molar ratios was prepared by the two-step method (sol-gel followed by the ultrasonic-assisted method). The as-prepared samples were fairly characterized by various characterization methods, such as X-ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM), Fourier Transform Infrared (FT-IR) and Thermal Gravimetric Analysis (TGA). The catalytic performance of the as-prepared samples was evaluated based on the degradation of methylene blue under UV light, ultrasound and combination of UV and ultrasound irradiation. The results revealed that the sample with Fe3O4:ZrO2 molar ratio of 0.5:1 showed the best catalytic performance under UV, ultrasound and UV + ultrasound irradiation. The degradation of methylene blue follows the order: sonophotocatalytic > sonocatalytic > photocatalytic. In addition, the effect of various scavengers has also been studied. Furthermore, all prepared samples could be used as a convenient recyclable catalyst.

Column performance of carbon nanotube packed bed for methylene blue and orange red dye removal from waste water

NASA Astrophysics Data System (ADS)

Gill, G. K.; Mubarak, N. M.; Nizamuddin, S.; Al-Salim, H. S.; Sahu, J. N.

2017-06-01

Environmental issues have always been a major issue among human kind for the past decades. As the time passes by, the technology field has grown and has helped a lot in order to reduce these environmental issues. Industries such as metal plating facilities, mining operations and batteries production are a few examples that involves in the environmental issues. Carbon nanotube is proven to possess excellent adsorption capacity for the removal of methylene blue and orange red dyes. The effect of process parameters such as pH and contact time was investigated The results revealed that optimized conditions for the highest removal for methylene blue (MB) (97%) and orange red (94%) are at pH 10, CNTs dosage of 1 grams, and 15 minutes for each dyes removal respectively. The equilibrium adsorption data obtained was best fit to Freundlich model, while kinetic data can be characterized by the pseudo second-order rate kinetics.

Biosorption of six basic and acidic dyes on brown alga Sargassum ilicifolium: optimization, kinetic and isotherm studies.

PubMed

Tabaraki, Reza; Sadeghinejad, Negar

2017-06-01

Biosorption of Methyl Blue (MB), Fuchsin Acid (FA), Rhodamine B (RB), Methylene Blue (MEB), Bromocresol purple (BC) and Methyl Orange (MO) onto Sargassum ilicifolium was studied in a batch system. Effect of dye structure on biosorption by Sargassum ilicifolium was studied to define the correlation between chemical structure and biosorption capacity. Different dye groups such as triarylmethane (MB, FA and BC), monoazo (MO), thiazine (MEB) and xanthene (RB) were studied. At optimum experimental conditions for each dye, biosorption capacity was determined and compared. The results indicate that the chemical structure (triarylmethane, monoazo, thiazine, xanthene), number of sulfonic groups, basicity (element of chromophore group: S, N, O) and molecular weight of dye molecules influence their biosorption capacity. Experimental parameters such as biosorbent dose, pH, contact time, and initial dye concentration were optimized for each dye. The biosorption kinetic data were successfully described by the pseudo second-order model. The biosorption results were also analyzed by the Langmuir and Freundlich isotherms. Finally, biosorption capacities obtained using Sargassum ilicifolium were compared with the ones presented in the literature.

Prevention and treatment of Nitrite toxicity in juvenile steelhead trout (Salmo gairdneri)

USGS Publications Warehouse

Wedemeyer, Gary A.; Yasutake, W.T.

1978-01-01

The efficacy of mineral salts, pH, and tetramethylthianine (methylene blue) treatment in reducing the acute toxicity of nitrite to fingerling steelhead trout (Salmo gairdneri) was determined using a static bioassay system at 10 °C. The acute toxicity (96-h LC50) was reduced by a factor of about 24 for 5-g steelhead and 13 for 10-g fish when the total water hardness was increased from 25 to 300 mg/L (as CaCO3). NaCl or CaCl2 additions (0–200 mg/L) reduced toxicity by a factor of up to 3 for NaCl and 50 for CaCl2. Increasing the pH from 6.0 to 8.0 decreased toxicity by a factor of about 8 for the smaller and 3 for the larger fish. Methylene blue at 0.1 or 1.0 mg/L was effective in decreasing acute toxicity. For alleviating methemoglobinemia, removing the fish to freshwater for 48 h was about as effective as 1.0 mg/L methylene blue. Chronic exposure in soft water to 0.03 mg/L NO2-N for 6 mo caused no significant growth reduction, gill histological changes, hematological dyscrasias, or impaired ability of the smolts to adapt to 30‰ seawater and grow for an additional 2 mo. Key words: nitrite, toxicity, fish, methylene blue, pH, salts, acute toxicity, chronic toxicity

[Efficacy of intracutaneous methylene blue injection for moderate to severe acute thoracic herpes zoster pain and prevention of postherpetic neuralgia in elderly patients].

PubMed

Cui, Ji-Zheng; Zhang, Jin-Wei; Zhang, Yun; Ma, Zheng-Liang

2016-10-20

To evaluate the clinical efficacy of intradermal injection of methylene blue for treatment of moderate to severe acute thoracic herpes zoster and prevention of postherpetica neuralgia in elderly patients. Sixty-four elderly patients with herpes zoster were randomized to receive a 10-day course of intradermal injection of methylene blue and lidocaine plus oral valaciclovir (group A, 32 cases) and intradermal injection of lidocaine plus oral valaciclovir (group B).Herpes evaluation index, pain rating index, incidence of postherpetic neuralgia, and comprehensive therapeutic effect were compared between the two groups at 11, 30 and 60 days after the treatment. The baseline characteristics were comparable between the two groups (all P>0.05). Compared with that in group B, the time for no new blister formation, blister incrustation and decrustation, and pain relief was significantly shortened in group A (P<0.05) with also obviously lower pain intensity after the treatment. The incidence of postherpetic neuralgia was significantly lower in group A than in group B at 30 days (P<0.05), but not at 60 and 90 days after the treatment. The total clinical response rate was 93.8% in group A, much higher than that in group B (62.5%, P<0.05). Intradermal injection of methylene blue can effectively shorten the disease course, reduce the pain intensity and prevent the development of postherpetic neuralgia in elderly patients with herpes zoster.

Novel methylene blue staining technique for localizing small esophageal leiomyomas during thoracoscopic enucleation.

PubMed

Zhang, Z; Ai, B; Liao, Y; Liu, L; Liu, M

2016-11-01

The treatment of choice for leiomyoma, the most common benign esophageal tumor, is thoracoscopic enucleation. One of the most difficult aspects of thoracoscopic enucleation is the precise localization of small tumors (≤1.5 cm) and tumors without external protrusion. No simple, feasible solutions to this problem are available. We developed a novel methylene blue staining technique to localize small esophageal leiomyomas and evaluated the feasibility of our technique. Between January 2013 and July 2014, eight patients with small esophageal leiomyomas (≤1.5 cm) underwent thoracoscopic enucleation in Tongji Hospital. Preoperative endoscopic ultrasonography was performed in all patients. The leiomyomas were located in the middle (n = 5) and lower (n = 3) thirds of the esophagus. We preoperatively injected 0.5-1.0 mL methylene blue in the submucosa adjacent to the tumors under standard gastroscope guidance. The entire staining process took about 10 minutes. Staining was successful in all patients. The unstained tumor was exposed after the blue-stained mediastinal pleura, and overlying muscle were incised longitudinally. All procedures were successfully completed without conversion to open surgery. No abnormalities were detected in the esophageal mucosa. The median operating time was 60 minutes (range, 40-90 minutes). Postoperative histopathology confirmed leiomyoma in all patients. The median postoperative hospital stay was 6 days (range, 5-7 days). No major complications, such as esophageal leakage or esophageal diverticulum, occurred. Endoscopic methylene blue staining is safe and feasible for localizing small esophageal leiomyomas during thoracoscopic enucleation. This method will enable precise and easy enucleation. © 2015 International Society for Diseases of the Esophagus.

A supramolecular photosensitizer system based on the host-guest complexation between water-soluble pillar[6]arene and methylene blue for durable photodynamic therapy.

PubMed

Yang, Kui; Wen, Jia; Chao, Shuang; Liu, Jing; Yang, Ke; Pei, Yuxin; Pei, Zhichao

2018-06-05

A supramolecular photosensitizer system WP6-MB was synthesized based on water-soluble pillar[6]arene and the photosensitizer methylene blue (MB) via host-guest interaction. MB can complex with WP6 directly with a high complex constant without further modification. In particular, WP6-MB can reduce the dark toxicity of MB remarkably. Furthermore, it can efficiently overcome photobleaching and extend the time for singlet oxygen production of MB upon light irradiation, which is significant for durable photodynamic therapy.

Photobactericidal activity of methylene blue derivatives against vancomycin-resistant Enterococcus spp.

PubMed

Wainwright, M; Phoenix, D A; Gaskell, M; Marshall, B

1999-12-01

The toxicities and phototoxicities of methylene blue and its two methylated derivatives were measured against one standard and three vancomycin-resistant pathogenic strains of Enterococcus spp. Each of the compounds was bactericidal and the derivatives exhibited photobactericidal activity on illumination at a 'light' dose of 6.3 J/cm(2) against one or more of the strains. Increased bactericidal and photobactericidal activity in the methylated derivatives is thought to be due to their higher hydrophobicities allowing greater interaction with the bacterial cell wall. In addition, the derivatives exhibited higher inherent photosensitizing efficacies.

[Effect of methylene blue on changes in inducible nitric oxide synthase in lung of rats with sepsis].

PubMed

Dai, Cheng; Wang, Yi; Yu, Xiangyou

2016-02-01

To study the time course of effect of methylene blue on inducible nitric oxide synthase (iNOS) mRNA transcription and protein expression in lung tissue of rats with sepsis, and its mechanism. 126 female Wistar rats were randomly divided into sham group, sepsis group and methylene blue group. Each group was subdivided into 0-, 6-, 12-, 18-, 24-, 30-, and 36-hour subgroups according to the time after operation, with 6 rats in each subgroup. A model of sepsis was reproduced by cecal ligation and puncture (CLP), and the rats in sham group were only opened the abdominal cavity and isolated the membrane of the appendix without CLP. Rats in methylene blue group were given injection of 15 mg/kg methylene blue at all time points after CLP, the remaining rats were given 0.9%NaCl solution in same amount. Six hours after the injection, the rats were sacrificed and the lung tissue was harvested immediately. The expression of iNOS mRNA and protein in lung tissues were determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western Blot respectively, and the changes in histopathology were observed using hematoxylin and eosin (HE) staining. Compared with sham group, the expression of iNOS mRNA was significantly up-regulated at 6, 12, 18 and 24 hours after CLP in sepsis group (2(-ΔΔCt): 2.42±0.66 vs. 1.00±0.38 at 6 hours, P = 0.002; 2.54±0.76 vs. 1.00±0.27 at 12 hours, P = 0.000; 5.46±2.26 vs. 1.00±0.38 at 18 hours, P = 0.000; 3.03±0.62 vs. 1.00±0.33 at 24 hours, P = 0.001), and iNOS protein expression was significantly up-regulated at 12, 18 and 24 hours (gray value: 2.54±0.45 vs. 1.00±0.35 at 12 hours, P = 0.000; 2.65±0.64 vs. 1.00±0.33 at 18 hours, P = 0.000; 3.03±0.59 vs. 1.00±0.24 at 24 hours, P = 0.000). Compared with sepsis group, the expression of iNOS mRNA was significantly down-regulated at 6, 12, 18 and 24 hours in methylene blue group (2(-ΔΔCt): 1.55±0.82 vs. 2.42±0.66 at 6 hours, P = 0.034; 1.84±0.42 vs. 2.54±0.76 at 12 hours, P = 0.016; 2.66±1.09 vs. 5.46±2.26 at 18 hours, P = 0.003; 2.20±0.29 vs. 3.03±0.62 at 24 hours, P = 0.002), and iNOS protein expression was significantly lowered at 12, 18 and 24 hours (gray value: 1.84±0.18 vs. 2.54±0.45 at 12 hours, P = 0.003; 1.87±0.27 vs. 2.65±0.64 at 18 hours, P = 0.008; 2.20±0.50 vs. 3.03±0.59 at 24 hours, P = 0.008). Histopathological observation showed that the degree of lung injury at each time point, including red blood cells effusion, lung interstitial edema, inflammatory cell infiltration, alveolar collapse etc., in sepsis group and methylene blue group were significantly higher than that of sham group, and the degree of lung injury in rats with methylene blue was not significantly improved as compared with that of sepsis group. Lung iNOS mRNA expression was significantly increased at 6-24 hours after CLP induced sepsis in rat, and protein expression was increased at 12-24 hours. Methylene blue could inhibit mRNA transcription and protein expression of iNOS in lung of septic rat, but failed to reduce the degree of lung injury in sepsis.

Homogeneous electrochemical immunoassay of aflatoxin B1 in foodstuff using proximity-hybridization-induced omega-like DNA junctions and exonuclease III-triggered isothermal cycling signal amplification.

PubMed

Tang, Juan; Huang, Yapei; Liu, Huiqiong; Zhang, Cengceng; Tang, Dianping

2016-12-01

A new homogeneous electrochemical immunosensing platform was designed for sensitive detection of aflatoxin B 1 (AFB 1 ) in foodstuff. The system consisted of anti-AFB 1 antibody labeled DNA 1 (Ab-DNA 1 ), AFB 1 -bovine serum albumin (BSA)-conjugated DNA 2 (AFB 1 -DNA 2 ), and methylene blue functionalized hairpin DNA. Owing to a specific antigen-antibody reaction between anti-AFB 1 and AFB 1 -BSA, the immunocomplex formed assisted the proximity hybridization of DNA 1 with DNA 2 , thus resulting in the formation of an omega-like DNA junction. Thereafter, the junction opened the hairpin DNA to construct a new double-stranded DNA, which could be readily cleaved by exonuclease III to release the omega-like DNA junction and methylene blue. The dissociated DNA junction could repeatedly hybridize with residual hairpin DNA molecules with exonuclease III-based isothermal cycling amplification, thereby releasing numerous free methylene blue molecules into the detection solution. The as-produced free methylene blue molecules could be captured by a negatively charged indium tin oxide electrode, each of which could produce an electronic signal within the applied potentials. On introduction of target AFB 1 , the analyte competed with AFB 1 -DNA 2 for the conjugated anti-AFB 1 on the Ab-DNA 1 , subsequently decreasing the amount of omega-like DNA junctions formed, hence causing methylene blue labeled hairpin DNA to move far away from the electrode surface. Under optimal conditions the detectable electrochemical signal decreased with increasing amount of target AFB 1 in a dynamic working range of 0.01-30 ng mL -1 with a detection limit of 4.8 pg mL -1 . In addition, the precision and reproducibility of this system were acceptable. Finally, the method was further evaluated for analysis of naturally contaminated or AFB 1 -spiked peanut samples, giving results that matched well with those obtained with a commercial AFB 1 ELISA kit.

Preparation of activated carbon from a renewable bio-plant of Euphorbia rigida by H 2SO 4 activation and its adsorption behavior in aqueous solutions

NASA Astrophysics Data System (ADS)

Gerçel, Özgül; Özcan, Adnan; Özcan, A. Safa; Gerçel, H. Ferdi

2007-03-01

The use of activated carbon obtained from Euphorbia rigida for the removal of a basic textile dye, which is methylene blue, from aqueous solutions at various contact times, pHs and temperatures was investigated. The plant material was chemically modified with H 2SO 4. The surface area of chemically modified activated carbon was 741.2 m 2 g -1. The surface characterization of both plant- and activated carbon was undertaken using FTIR spectroscopic technique. The adsorption process attains equilibrium within 60 min. The experimental data indicated that the adsorption isotherms are well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacity of activated carbon was 114.45 mg g -1 at 40° C. The adsorption kinetics of methylene blue obeys the pseudo-second-order kinetic model and also followed by the intraparticle diffusion model up to 60 min. The thermodynamic parameters such as Δ G°, Δ H° and Δ S° were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 55.51 kJ mol -1. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal textile dyes from textile wastewater processes.

Applications of Brazilian pine-fruit shell in natural and carbonized forms as adsorbents to removal of methylene blue from aqueous solutions--kinetic and equilibrium study.

PubMed

Royer, Betina; Cardoso, Natali F; Lima, Eder C; Vaghetti, Julio C P; Simon, Nathalia M; Calvete, Tatiana; Veses, Renato Cataluña

2009-05-30

The Brazilian pine-fruit shell (Araucaria angustifolia) is a food residue, which was used in natural and carbonized forms, as low-cost adsorbents for the removal of methylene blue (MB) from aqueous solutions. Chemical treatment of Brazilian pine-fruit shell (PW), with sulfuric acid produced a non-activated carbonaceous material (C-PW). Both PW and C-PW were tested as low-cost adsorbents for the removal of MB from aqueous effluents. It was observed that C-PW leaded to a remarkable increase in the specific surface area, average porous volume, and average porous diameter of the adsorbent when compared to PW. The effects of shaking time, adsorbent dosage and pH on adsorption capacity were studied. In basic pH region (pH 8.5) the adsorption of MB was favorable. The contact time required to obtain the equilibrium was 6 and 4h at 25 degrees C, using PW and C-PW as adsorbents, respectively. Based on error function values (F(error)) the kinetic data were better fitted to fractionary-order kinetic model when compared to pseudo-first order, pseudo-second order, and chemisorption kinetic models. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. For MB dye the equilibrium data were better fitted to the Sips isotherm model using PW and C-PW as adsorbents.

Visible-Light Organic Photocatalysis for Latent Radical-Initiated Polymerization via 2e–/1H+ Transfers: Initiation with Parallels to Photosynthesis

PubMed Central

2015-01-01

We report the latent production of free radicals from energy stored in a redox potential through a 2e–/1H+ transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e–/1H+ shuttle mechanism, as opposed to the 1e– transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the “storage” of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes. PMID:24786755

Visible-light organic photocatalysis for latent radical-initiated polymerization via 2e⁻/1H⁺ transfers: initiation with parallels to photosynthesis.

PubMed

Aguirre-Soto, Alan; Lim, Chern-Hooi; Hwang, Albert T; Musgrave, Charles B; Stansbury, Jeffrey W

2014-05-21

We report the latent production of free radicals from energy stored in a redox potential through a 2e(-)/1H(+) transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e(-)/1H(+) shuttle mechanism, as opposed to the 1e(-) transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the "storage" of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes.

Graphene quantum dot synthesis using nanosecond laser pulses and its comparison to Methylene Blue

NASA Astrophysics Data System (ADS)

Kholikov, Khomidkhodza; Thomas, Zachary; Seyitliyev, Dovletgeldi; Smith, Skylar

A biocompatible photodynamic therapy agent that generates a high amount of singlet oxygen with high water dispersibility and excellent photostability is desirable. In this work, a graphene based biomaterial which is a promising alternative to a standard photosensitizers was produced. Methylene blue was used as a reference photosensitizer. Bacteria deactivation by methylene blue was shown to be inhibited inside human blood due to protein binding. Graphene quantum dots (GQD) were synthesized by irradiating benzene and nickel oxide mixture using nanosecond laser pulses. High resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) were used for characterization of GQDs. Initial results show graphene quantum dots whose size less than 5 nm were successfully obtained. UV-VIS spectra shows absorption peak around 310 nm. The results of these studies can potentially be used to develop therapies for the eradication of pathogens in open wounds, burns, or skin cancers. New therapies for these conditions are particularly needed when antibiotic-resistant infections are present. NIH KBRIN.

Combination photodynamic therapy of human breast cancer using salicylic acid and methylene blue

NASA Astrophysics Data System (ADS)

Hosseinzadeh, Reza; Khorsandi, Khatereh; Jahanshiri, Maryam

2017-09-01

The objective of this study was to evaluate the effects of combination therapy with methylene blue (MB) assisted photodynamic therapy (PDT) and salicylic acid (SA) as chemo-therapy anticancer agent. The binding of salicylic acid to methylene blue was studied using spectrophotometric method. The results show the 1:2 complex formation between SA and MB. The binding constants and related Gibbs free energies o are obtained (Kb1 = 183.74, Kb2 = 38.13 and ∆ Gb1° = 12.92 kJ·mol- 1, ∆ Gb2° =9.02 kJ·mol- 1). The spectrophotometric results show the improvement in solubilization and reduction prevention for SA and MB in the complex form. These results are in agreements with cellular experiments. The dark toxicity measurements represent the improve efficacy of chemotherapy using combination of SA and MB. The photodynamic therapy results (using red LED as light source (630 nm; power density: 30 mW cm- 2)) show that the cancer cell killing efficiency of MB increases in the combination with SA due to reduction prevention and stabilization of monomeric form of MB.

Enhanced photocatalytic degradation of methylene blue by metal-modified silicon nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brahiti, N., E-mail: dihiabrahiti@yahoo.fr; Université Mouloud MAMMERI de TiziOuzou, Département de Physique, Bastos; Hadjersi, T., E-mail: hadjersi@gmx.com

2015-02-15

Highlights: • SiNWs modified with Pd, Au and Pt were used as photocatalysts to degrade MB. • Yield of photodegardation increases with UV irradiation time. • SiNWs modified with Pd nanoparticles show the best photocatalytic activity. • A degradation of 97% was obtained after 200 min of UV irradiation. - Abstract: Silicon nanowires (SiNWs) modified with Au, Pt and Pd nanoparticles were used as heterogeneous photocatalysts for the photodegradation of methylene blue in water under UV light irradiation. The modification of SiNWs was carried out by deposition of metal nanoparticles using the electroless metal deposition (EMD) technique. The effect ofmore » metal nanoparticles deposition time on the photocatalytic activity was studied. It was found that the photocatalytic activity of modified SiNWs was enhanced when the deposition time of metal nanoparticles was increased. In addition of modified SiNWs with Pt, Au and Pd nanoparticles, oxidized silicon substrate (Ox-Si), oxidized silicon nanowires (Ox-SiNWs) and hydrogen-terminated silicon nanowires (H-SiNWs) were also evaluated for the photodegradation of methylene blue.« less

Stainless steel wire mesh-supported ZnO for the catalytic photodegradation of methylene blue under ultraviolet irradiation.

PubMed

Vu, Tan T; del Río, Laura; Valdés-Solís, Teresa; Marbán, Gregorio

2013-02-15

The aim of this study was to assess the activity of catalysts formed by nanostructured zinc oxide supported on stainless steel wire mesh for the photocatalytic degradation of methylene blue under UV irradiation. Catalysts prepared by means of different low temperature synthesis methods, as described in a previous work (Vu et al., Mater. Res. Bull. 47 (2012) 1577-1586) were tested. A new activity parameter was introduced in order to compare the catalytic activity of the different catalysts. The best catalyst showed a catalytic activity higher than that of the reference material TiO(2) P25 (Degussa-Evonik). This high activity is attributed to a higher quantum yield derived from the small particle length of the ZnO deposited on the wire mesh. The photocatalytic degradation kinetics of methylene blue fitted a potential model with n orders ranging from 0.5 to 6.9. Reaction orders over 1 were attributed to catalyst deactivation during the reaction resulting from the photocorrosion of ZnO. Copyright © 2012 Elsevier B.V. All rights reserved.

A case of severe chlorite poisoning successfully treated with early administration of methylene blue, renal replacement therapy, and red blood cell transfusion: case report.

PubMed

Gebhardtova, Andrea; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Seelen, Mark; Dobisova, Anna; Flassikova, Zora; Cikova, Andrea; Henning, Robert H; Yaghi, Aktham

2014-08-01

The case of a 55-year-old man who attempted suicide by ingesting <100 mL of 28% sodium chlorite solution is presented. On arrival in the intensive care unit, the patient appeared cyanotic with lowered consciousness and displayed anuria and chocolate brown serum.Initial laboratory tests revealed 40% of methemoglobin. The formation of methemoglobin was effectively treated with methylene blue (10% after 29 hours).To remove the toxin, and because of the anuric acute renal failure, the patient received renal replacement therapy. Despite these therapeutic measures, the patient developed hemolytic anemia and disseminated intravascular coagulation, which were treated with red blood cell transfusion and intermittent hemodialysis. These interventions led to the improvement of his condition and the patient eventually fully recovered. Patient gave written informed consent.This is the third known case of chlorite poisoning that has been reported. Based upon this case, we suggest the management of sodium chlorite poisoning to comprise the early administration of methylene blue, in addition to renal replacement therapy and transfusion of red blood cells.

A Case of Severe Chlorite Poisoning Successfully Treated With Early Administration of Methylene Blue, Renal Replacement Therapy, and Red Blood Cell Transfusion

PubMed Central

Gebhardtova, Andrea; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Seelen, Mark; Dobisova, Anna; Flassikova, Zora; Cikova, Andrea; Henning, Robert H.; Yaghi, Aktham

2014-01-01

Abstract The case of a 55-year-old man who attempted suicide by ingesting <100 mL of 28% sodium chlorite solution is presented. On arrival in the intensive care unit, the patient appeared cyanotic with lowered consciousness and displayed anuria and chocolate brown serum. Initial laboratory tests revealed 40% of methemoglobin. The formation of methemoglobin was effectively treated with methylene blue (10% after 29 hours). To remove the toxin, and because of the anuric acute renal failure, the patient received renal replacement therapy. Despite these therapeutic measures, the patient developed hemolytic anemia and disseminated intravascular coagulation, which were treated with red blood cell transfusion and intermittent hemodialysis. These interventions led to the improvement of his condition and the patient eventually fully recovered. Patient gave written informed consent. This is the third known case of chlorite poisoning that has been reported. Based upon this case, we suggest the management of sodium chlorite poisoning to comprise the early administration of methylene blue, in addition to renal replacement therapy and transfusion of red blood cells. PMID:25144325

Synthesis of zeolite/nickel ferrite/sodium alginate bionanocomposite via a co-precipitation technique for efficient removal of water-soluble methylene blue dye.

PubMed

Bayat, Mahsa; Javanbakht, Vahid; Esmaili, Javad

2018-05-05

In this study, we sought to synthesize magnetic nanocomposite of zeolite/nickel ferrite through co-precipitation method and modify its surface by sodium alginate to enhance its methylene blue adsorption capacity and to prevent its oxidation. Nanocomposite characteristics were investigated by SEM, VSM, XRD and FTIR analyses. The results indicate that nanocomposite synthesis and modification has been completely successful. Adsorption thermodynamics, kinetics, and isotherms were examined and parameters were optimized by Minitab software using experimental design method, response surface methodology and Box-Behnken design. The highest capacity of methylene blue adsorption from the aqueous solution obtained at optimal pH of 5, the initial dye concentration of 10 mg/L and an adsorbent amount of 0.03 g was about 54.05 mg/g. Analyzing kinetic data of adsorption experiments confirmed that adsorption process complies with the pseudo-second-order kinetic model. Assessing equilibrium isotherm data at different temperatures showed that these data are in good agreement with Langmuir isotherm model. Copyright © 2018 Elsevier B.V. All rights reserved.

A facile approach to fabricate porous nanocomposite gels based on partially hydrolyzed polyacrylamide and cellulose nanocrystals for adsorbing methylene blue at low concentrations.

PubMed

Zhou, Chengjun; Lee, Sunyoung; Dooley, Kerry; Wu, Qinglin

2013-12-15

Porous nanocomposite gels were fabricated by a facile method consisting of the electrospinning and subsequent heat treatment based on partially hydrolyzed polyacrylamide (HPAM) of ultra-high molecular weight, with cellulose nanocrystals (CNCs) as crosslinker. The effects of three electrospinning parameters (i.e., solution concentration, composition of solvent mixture, and CNC loading level) on morphology and diameter of electrospun fibers were systematically investigated. The swelling properties of porous gels and their application in the removal of methylene blue dye (as a compound representative of contaminants) were evaluated. Electrospun fiber morphologies without beads, branches, and ribbons were achieved by optimizing the electrospinning solutions. The thermal crosslinking between HPAM and CNCs was realized through esterification, rendering the product nanocomposite membranes insoluble in water. Electrospun fibers of approximately 220 nm in diameter comprised the 3D porous nanocomposite gels, with porosity greater than 50%. The porous nanocomposite gels displayed a rapid swelling rate and an efficient adsorption capacity in removing methylene blue at low concentrations from aqueous solutions. Copyright © 2013 Elsevier B.V. All rights reserved.

Cross-linked beads of activated oil palm ash zeolite/chitosan composite as a bio-adsorbent for the removal of methylene blue and acid blue 29 dyes.

PubMed

Khanday, W A; Asif, M; Hameed, B H

2017-02-01

Cross-linked beads of activated oil palm ash zeolite/chitosan (Z-AC/C) composite were prepared through the hydrothermal treatment of NaOH activated oil palm ash followed by beading with chitosan. The effects of initial dye concentration (50-400mg/L), temperature (30°C-50°C) and pH (3-13) on batch adsorption of methylene blue (MB) and acid blue 29 (AB29) were studied. Adsorption of both dyes was better described by Pseudo-second-order kinetics and Freundlich isotherm model. The maximum adsorption capacities of Z-AC/C were 151.51, 169.49, and 199.20mg/g for MB and 212.76, 238.09, and 270.27mg/g for AB29 at 30°C, 40°C, and 50°C, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Copper Doped Methylene Blue Sensitized Poly(vinyl alcohol)-Acrylamide Films for Stable Diffraction Efficiency

NASA Astrophysics Data System (ADS)

John, Beena Mary; Joseph, Rani; Sreekumar, K.; Sudha Kartha, C.

2006-11-01

Copper doped methylene blue sensitized poly(vinyl alcohol) (MBPVA)-acrylamide films were fabricated to improve the storage life of recorded gratings. The films were fabricated using gravity settling method and the copper chloride concentration was optimized as 3.18× 10-3 mol/l for a dye concentration of 6.2× 10-4 mol/l. The gratings recorded on the optimized film constitution could be stored for months with stable diffraction efficiency (24%) without any chemical or thermal fixing techniques. The resolution of the material is found to be unaffected with the addition of copper chloride.

A severe case of vasoplegic shock following metformin overdose successfully treated with methylene blue as a last line therapy

PubMed Central

Graham, Rachel Erin; Cartner, Michaela; Winearls, James

2015-01-01

A 44-year-old man presented to hospital 24 h after an intentional overdose of metformin and gliclazide. He had a critical metabolic acidosis on presentation with a pH of 6.88, and very rapidly deteriorated into distributive shock refractory to large volume fluid resuscitation and massive doses of vasopressors. We introduced a methylene blue infusion as a rescue therapy in an attempt to improve the patient's haemodynamics, which was successful. The patient made a full recovery with no long-term sequelae. PMID:26150642

Acquired Methemoglobinemia - A Sporadic Holi Disaster.

PubMed

Masavkar, Sanjeevani Satish; Mauskar, Anupama; Patwardhan, Gaurav; Bhat, Vasudeva; Manglani, Mamta V

2017-06-15

To study clinical profile and outcome in patients with methemoglobinemia following exposure to toxic colors during Holi festival. This retrospective study included 112 children (5 to 12 years) admitted with methemoglobinemia after playing Holi. Clinical and treatment details were reviewed. The common symptoms were giddiness, vomiting and headache. Treatment included thorough skin wash, intravenous fluid and methylene blue in 111 children. Age 7-9 and > 11 years, vomiting, giddiness, cyanosis, PaO2 < 80 mm Hg and oxygen saturation < 95% were associated with higher need for methylene blue. All children had a good outcome. Timely diagnosis and management of acquired methemoglobinemia can save lives.

Adsorption of Dyes in Studying the Surface Chemistry of Ultradispersed Diamond

NASA Astrophysics Data System (ADS)

Khokhlova, T. D.; Yunusova, G. R.; Lanin, S. N.

2018-05-01

The effect the surface chemistry of ultradispersed diamond (UDD) has on the adsorption of watersoluble dyes is considered. A comparison is made to adsorption on graphitized thermal carbon black (GTCB), which has a homogeneous and nonporous surface. The adsorption isotherms of dyes and the dependence of the adsorption on the pH of solutions are measured. It is found that UDD adsorbs acid (anionic) dyes—acid orange (AO) and acid anthraquinone blue (AAB)—but barely adsorbs a basic (cationic) dye, methylene blue (MB), because of the predominance of positively charged basic groups on the surface of UDD. The maximum adsorption of AO is much lower on UDD than on GTCB, while the maximum adsorption of AAB is similar for both surfaces. The adsorption of AO on UDD depends strongly on the pH of the solution, while the adsorption of AAB is independent of this parameter. It is suggested that the adsorption of AAB is determined not only by ionic and hydrophobic interactions but also by coordination interactions with impurity metal ions on a UDD surface. It is concluded that the adsorption of dyes characterizes the chemistry of a UDD surface with high sensitivity.

Submucosal tunneling endoscopic resection using methylene-blue guidance for cardial subepithelial tumors originating from the muscularis propria layer.

PubMed

Mao, Xin-Li; Ye, Li-Ping; Zheng, Hai-Hong; Zhou, Xian-Bin; Zhu, Lin-Hong; Zhang, Yu

2017-02-01

Submucosal tunneling endoscopic resection (STER) of subepithelial tumors (SETs) originating from the muscularis propria (MP) layer in the cardia is rarely performed due to the difficulty of creating a submucosal tunnel for resection. The aim of this study was to evaluate the feasibility of STER using methylene-blue guidance for SETs originating from the MP layer in the cardia. From January 2012 to December 2014, 56 patients with SETs originating from the MP layer in the cardia were treated with STER using methylene-blue guidance. The complete resection rate and adverse event rate were the main outcome measurements. Successful complete resection by STER was achieved in all 56 cases (100%). The median size of the tumor was 1.8 cm. Nine patients (15.3%) had adverse events including subcutaneous emphysema, pneumoperitoneum, pneumothorax, and pleural effusion. These nine patients recovered successfully after conservative treatment without endoscopic or surgical intervention. No residual or recurrent tumors were detected in any patient during the follow-up period (median, 25 months). The adverse event rate was significantly higher for tumors originating in the deeper MP layers (46.7%) than in the superficial MP layers (4.9%) (P < 0.05), differed significantly according to tumor size (5.4% for tumors < 2.0 cm vs. 36.8% for tumors ≥ 2.0 cm; P < 0.05), and also differed significantly in relation to the tumor growth pattern (4.1% for the intraluminal growth vs. 100% for the extraluminal growth; P < 0.001). STER using methylene-blue guidance appears to be a feasible method for removing SETs originating from the MP layer in the cardia. © 2017 International Society for Diseases of the Esophagus.

Development of electrospun beaded fibers from Thai silk fibroin and gelatin for controlled release application.

PubMed

Somvipart, Siraporn; Kanokpanont, Sorada; Rangkupan, Rattapol; Ratanavaraporn, Juthamas; Damrongsakkul, Siriporn

2013-04-01

Thai silk fibroin and gelatin are attractive biomaterials for tissue engineering and controlled release applications due to their biocompatibility, biodegradability, and bioactive properties. The development of electrospun fiber mats from silk fibroin and gelatin were reported previously. However, burst drug release from such fiber mats remained the problem. In this study, the formation of beads on the fibers aiming to be used for the sustained release of drug was of our interest. The beaded fiber mats were fabricated using electrospinning technique by controlling the solution concentration, weight blending ratio of Thai silk fibroin/gelatin blend, and applied voltage. It was found that the optimal conditions including the solution concentration and the weight blending ratio of Thai silk fibroin/gelatin at 8-10% (w/v) and 70/30, respectively, with the applied voltage at 18 kV provided the fibers with homogeneous formation of beads. Then, the beaded fiber mats obtained were crosslinked by the reaction of carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS). Methylene blue as a model active compound was loaded on the fiber mats. The release test of methylene blue from the beaded fiber mats was carried out in comparison to that of the smooth fiber mats without beads. It was found that the beaded fiber mats could prolong the release of methylene blue, comparing to the smooth fiber mats without beads. This was possibly due to the beaded fiber mats that would absorb and retain higher amount of methylene blue than the fiber mats without beads. Thai silk fibroin/gelatin beaded fiber mats were established as an effective carrier for the controlled release applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Engendering Allograft Ignorance in a Mouse Model of Allogeneic Skin Transplantation to the Distal Hind Limb

PubMed Central

Agarwal, Shailesh; Loder, Shawn; Wood, Sherri; Cederna, Paul S.; Bishop, D. Keith; Wang, Stewart C.; Levi, Benjamin

2015-01-01

Objective The aim of this study was to demonstrate lymphatic isolation in a model of hind limb lymph node (LN) excision, consisting of ipsilateral popliteal and inguinal LN excision and to evaluate the immunologic response to allogeneic skin transplanted onto this region of lymphatic isolation. Methods To study lymphatic flow, C57BL/6 mice underwent lymphadenectomy (n = 5), sham lymphadenectomy (n = 5), or no intervention (n = 5), followed by methylene blue injection. Mice were dissected to determine whether methylene blue traveled to the iliac LN. To study host response to skin transplantation, C57BL/6 mice underwent allogeneic skin transplantation with LN excision (n = 6), allogeneic skin transplantation alone (n = 6), or syngeneic skin transplantation (n = 4). Skin grafts were placed distal to the popliteal fossa and mice were euthanized at day 10. Grafts were stained for endothelial cell and proliferation markers (CD31 and Ki67, respectively). Secondary lymphoid tissues (spleen, ipsilateral axillary LN, and contralateral inguinal LN) were removed and rechallenged with BALB/c alloantigen in vitro with subsequent assay of interferon-γ and interleukin 4 cell expression using ELISPOT technique. Results Mice that underwent LN excision had no evidence of methylene blue in the iliac nodes; mice without surgical intervention or with sham LN excision consistently had methylene blue visible in the ipsilateral iliac nodes. Mice treated with allogeneic skin transplantation and LN excision had lower expression of interferon-γ and interleukin 4 in the secondary lymphoid tissues. Conclusions Lymph node excision completely interrupts lymphatic flow of the hind limb. This model of lymphatic isolation impairs the ability of the transplant recipient to acutely mount a Th1 or Th2 response to allogeneic skin transplants. PMID:24509194

The Interactions of P-Glycoprotein with Antimalarial Drugs, Including Substrate Affinity, Inhibition and Regulation

PubMed Central

Senarathna, S M D K Ganga; Page-Sharp, Madhu; Crowe, Andrew

2016-01-01

The combination of passive drug permeability, affinity for uptake and efflux transporters as well as gastrointestinal metabolism defines net drug absorption. Efflux mechanisms are often overlooked when examining the absorption phase of drug bioavailability. Knowing the affinity of antimalarials for efflux transporters such as P-glycoprotein (P-gp) may assist in the determination of drug absorption and pharmacokinetic drug interactions during oral absorption in drug combination therapies. Concurrent administration of P-gp inhibitors and P-gp substrate drugs may also result in alterations in the bioavailability of some antimalarials. In-vitro Caco-2 cell monolayers were used here as a model for potential drug absorption related problems and P-gp mediated transport of drugs. Artemisone had the highest permeability at around 50 x 10−6 cm/sec, followed by amodiaquine around 20 x 10−6 cm/sec; both mefloquine and artesunate were around 10 x 10−6 cm/sec. Methylene blue was between 2 and 6 x 10−6 cm/sec depending on the direction of transport. This 3 fold difference was able to be halved by use of P-gp inhibition. MRP inhibition also assisted the consolidation of the methylene blue transport. Mefloquine was shown to be a P-gp inhibitor affecting our P-gp substrate, Rhodamine 123, although none of the other drugs impacted upon rhodamine123 transport rates. In conclusion, mefloquine is a P-gp inhibitor and methylene blue is a partial substrate; methylene blue may have increased absorption if co-administered with such P-gp inhibitors. An upregulation of P-gp was observed when artemisone and dihydroartemisinin were co-incubated with mefloquine and amodiaquine. PMID:27045516

Highly labeled methylene blue-ds DNA silica nanoparticles for signal enhancement of immunoassays: application to the sensitive detection of bacteria in human platelet concentrates.

PubMed

Bonnet, Romaric; Farre, Carole; Valera, Lionel; Vossier, Ludivine; Léon, Fanny; Dagland, Typhaine; Pouzet, Agnès; Jaffrézic-Renault, Nicole; Fareh, Jeannette; Fournier-Wirth, Chantal; Chaix, Carole

2018-05-15

A nanoparticle-based electrochemical sandwich immunoassay was developed for bacteria detection in platelet concentrates. For the assay, magnetic beads were functionalized with antibodies to allow the specific capture of bacteria from the complex matrix, and innovative methylene blue-DNA/nanoparticle assemblies provided the electrochemical response for amplified detection. This nanoparticular system was designed as a temperature-sensitive nano-tool for electrochemical detection. First, oligonucleotide-functionalized nanoparticles were obtained by direct synthesis of the DNA strands on the nanoparticle surface using an automated oligonucleotide synthesizer. Densely packed DNA coverage was thus obtained. Then, DNA duplexes were constructed on the NP surface with a complementary strand bearing a 3 methylene blue tag. This strategy ultimately produced highly functionalized nanoparticles with electrochemical markers. These assemblies enabled amplification of the electrochemical signal, resulting in a very good sensitivity. A proof-of-concept was carried out for E. coli detection in human platelet concentrates. Bacterial contamination of this complex biological matrix is the highest residual infectious risk in blood transfusion. The development of a rapid assay that could reach 10-102 CFU mL-1 sensitivity is a great challenge. The nanoparticle-based electrochemical sandwich immunoassay carried out on a boron doped diamond electrode proved to be sensitive for E. coli detection in human platelets. Two antibody pairs were used to develop either a generic assay against certain Gram negative strains or a specific assay for E. coli. The methylene blue-DNA/nanoparticles amplify sensitivity ×1000 compared with the assay run without NPs for electrochemical detection. A limit of detection of 10 CFU mL-1 in a biological matrix was achieved for E. coli using the highly specific antibody pair.

The correlation between structural properties, geometrical features, and photoactivity of freestanding TiO2 nanotubes in comparative degradation of 2,4-dichlorophenol and methylene blue

NASA Astrophysics Data System (ADS)

Vahabzadeh Pasikhani, Javad; Gilani, Neda; Ebrahimian Pirbazari, Azadeh

2018-02-01

Freestanding TiO2 nanotubes (FSNTs) with various physical dimensions were fabricated by two-step anodization process with different voltages and anodization times. The detachment method employed in this study involved voltage reduction at the end of the second step and ultrasonic chemical treatment. The results demonstrated that this detachment method is a beneficial technique to create thin open-mouthed and closed-end FSNTs (with lengths of 6-14 μm). Moreover, the influences of anodization conditions on photocatalytic activity, structural properties and geometrical features of FSNTs in comparative degradation of two non-colored (2,4-dichlorophenol) and colored (methylene blue) pollutants were investigated. Findings revealed that the quantity of the photocatalyst utilized is an effective parameter and using the optimum weight (10 mg/100 ml of 2,4-dichlorophenol) could increase the efficiency of the process up to 21%. Further, the results demonstrated that if equal optimum weights of FSNTs are chosen, decreases in voltage and anodization time significantly influence the structural properties, geometrical features, and photodegradation efficiency. The enhancement achieved in the degradation of both 2,4-dichlorophenol and methylene blue using the nanotubes with the shortest diameter (54 nm) and length (6.5 μm), which possess the lowest porosity (0.5) and also the highest surface area (0.53 m2 g-1), nanotubes’ density (19 cm2 cm-2) and wall thickness to length ratio (2). In addition, the results obtained indicated that the degradation reactions follow first-order kinetics in the degradation of the both pollutants. The apparent degradation rate constant of methylene blue was approximately 1.2 times greater than of the 2,4-dichlorophenol due to the negative charge of the nanotubes’ surface and electrostatic adsorptions.

Evaluation of gene expression SAP5, LIP9, and PLB2 of Candida albicans biofilms after photodynamic inactivation.

PubMed

Freire, Fernanda; de Barros, Patrícia Pimentel; da Silva Ávila, Damara; Brito, Graziella Nuernberg Back; Junqueira, Juliana Campos; Jorge, Antonio Olavo Cardoso

2015-07-01

With the increasing number of strains of Candida ssp. resistant to antifungal agents, the accomplishment of researches that evaluate the effects of new therapeutic methods, like photodynamic inactivation (PDI), becomes important and necessary. Thus, the objective of this study was to verify the effects of the PDI on Candida albicans biofilms, evaluating their effects on the expression of the gene hydrolytic enzymes aspartyl proteinase (SAP5), lipase (LIP9), and phospholipase (PLB2). Clinical strains of C. albicans (n = 9) isolated from patient bearers of the virus HIV and a pattern strain ATCC 18804 were used. The quantification of gene expression was related to the production of hydrolytic enzymes using the quantitative polymerase chain reaction (qPCR) assay. For PDI, we used laser-aluminum-gallium arsenide low power (red visible, 660 nm) as a light source and the methylene blue at 300 μM as a photosensitizer. We assessed two experimental groups for each strain: (a) PDI: sensitization with methylene blue and laser irradiation and (b) control: without sensitization with methylene blue and light absence. The PDI decreased gene expression in 60 % of samples for gene SAP5 and 50 % of the samples decreased expression of LIP9 and PLB2. When we compared the expression profile for of each gene between the treated and control group, a decrease in all gene expression was observed, however no statistically significant difference (Tukey's test/p = 0.12). It could be concluded that PDI (photosensitization with methylene blue followed by low-level laser irradiation) showed a slight reduction on the expression of hydrolytic enzymes of C. albicans, without statistical significance.

Modification of mutagenesis initiated by ultraviolet light through posttreatment of bacteria with basic dyes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witkin, E M

1961-12-01

Post treatment with basic dyes, in concentrations that retard cell division, was found to influence the tnduction of mutations to prototrophy by UV light in a tyrosine-requirtng strain of E.Coli. Pyronin, which is unique among the dyes in tts selective affinity for RNA, was found to duplicate the effects of chloramphenicol or amino acfd deprtvatfon in causfng the rapid and irreversible loss of potential prototrophs (mutation frequency decline, or MFD). Acriflavtne, methyl green. crystal violet, methylene blue, and toluidine blue, all of which are known to combine with DNA, delay or retard the occurrence of MFD under conditions of aminomore » acid deprivation. When acriflavine is removed from its combination with cellular components by the addition of an excess of sodium deoxyrtbonucleate, MFD begins promptly. The same basic dyes that delay MFD were also found to interfere with the fixation of mutations (MF) in an amino acid- enriched medium, and to cause marked enhancement of the mutagenic potency of low doses of UV light. While showing no independent mutagenic activity for unirradiated bacteria, all the dyes except pyronin increased the yield of induced mutations signtficantly when added to the enriched medium upon which trradiated bacteria were incubated.These results were interpreted as evidence that UV light initiates mutagenesis by producing unstable changas directly in genic DNA. MFD is interpreted as a repair process, blocked by the machinery of RNA and protein synthesis and by the presence of certain basic dyes.« less

Synthesis of α-MoO{sub 3} nanoplates using organic aliphatic acids and investigation of sunlight enhanced photodegradation of organic dyes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, V. Vinod; Gayathri, K.; Anthony, Savarimuthu Philip, E-mail: philip@biotech.sastra.edu

Graphical abstract: Thermodynamically stable α-MoO{sub 3} nanoplates and nanorods were synthesized using organic structure controlling agents and demonstrated sun light enhanced photocatalytic degradation of methylene blue (MB) and rhodamine blue (Rh-B) dyes in aqueous solution. - Highlights: • α-MoO{sub 3} hexagonal nanoplates using organic structure controlling agents. • Tunable optical band gap of MoO{sub 3}. • Demonstrated strong sun light mediated enhanced photodegradation of methylene blue and rhodamine blue. • Photodegradation did not use any other external oxidizing agents. - Abstract: Thermodynamically stable α-MoO{sub 3} nanoplates were synthesized using organic aliphatic acids as structure controlling agents and investigated photocatalytic degradationmore » of methylene blue (MB) and rhodamine blue (Rh-B) in presence of sun light. Three different organic aliphatic acids, citric acid (CA), tartaric acid (TA) and ethylene diamine tetra-acetic acid (EDTA), were employed to control morphologies. CA and TA predominantly produced extended hexagonal plates where EDTA gave nanorods as well as nanoplates. PXRD studies confirmed the formation of α-MoO{sub 3} nanoparticles. HR-TEM and FE-SEM reveal the formation of plate morphologies with 20–40 nm thickness, 50–100 nm diameter and 600 nm lengths. The different morphologies of α-MoO{sub 3} nanoparticles lead to the tunable optical band gap between 2.80 and 2.98 eV which was obtained from diffused reflectance spectra (DRS). Interestingly, the synthesized α-MoO{sub 3} nanoplates exhibited strong photocatalytic degradation of MB and Rh-B up to 99% in presence of sun light without using any oxidizing agents.« less

Antimicrobial photodynamic inactivation of Staphylococcus aureus biofilms in bone specimens using methylene blue, toluidine blue ortho and malachite green: An in vitro study.

PubMed

Rosa, Luciano Pereira; da Silva, Francine Cristina; Nader, Sumaia Alves; Meira, Giselle Andrade; Viana, Magda Souza

2015-05-01

To evaluate the in vitro effectiveness of APDI with a 660 nm laser combined with methylene blue (MB), toluidine blue ortho (TBO) and malachite green (MG) dyes to inactivate Staphylococcus aureus (ATCC 25923) biofilms in compact and cancellous bone specimens. Eighty specimens of compact and 80 of cancellous bone were contaminated with a standard suspension of the microorganism and incubated for 14 days at 37°C to form biofilms. After this period, the specimens were divided into groups (n=10) according to established treatment: PS-L- (control - no treatment); PSmb+L-, PStbo+L-, PSmg+L- (only MB, TBO or MG for 5 min in the dark); PS-L+ (only laser irradiation for 180 s); and APDImb, APDItbo and APDImg (APDI with MB, TBO or MG for 180 s). The findings were statistically analyzed by ANOVA at 5% significance levels. All experimental treatments showed significant reduction of log CFU/mL S. aureus biofilms when compared with the control group for compact and cancellous bones specimens; the APDI group's treatment was more effective. The APDI carried out for the compact specimens showed better results when compared with cancellous specimens at all times of application. For the group of compact bone, APDImg showed greater reductions in CFU/mL (4.46 log 10). In the group of cancellous bone, the greatest reductions were found in the APDImb group (3.06 log 10). APDI with methylene blue, toluidine blue ortho and malachite green dyes and a 660 nm laser proved to be effective in the inactivation of S. aureus biofilms formed in compact and cancellous bone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergistic reaction of silver nitrate, silver nanoparticles, and methylene blue against bacteria

PubMed Central

Li, Runze; Chen, Jie; Cesario, Thomas C.; Wang, Xin; Yuan, Joshua S.; Rentzepis, Peter M.

2016-01-01

In this paper we describe the antibacterial effect of methylene blue, MB, and silver nitrate reacting alone and in combination against five bacterial strains including Serratia marcescens and Escherichia coli bacteria. The data presented suggest that when the two components are combined and react together against bacteria, the effects can be up to three orders of magnitude greater than that of the sum of the two components reacting alone against bacteria. Analysis of the experimental data provides proof that a synergistic mechanism is operative within a dose range when the two components react together, and additive when reacting alone against bacteria. PMID:27849602

Modification of semi-coke powder and its adsorption mechanisms for Cr(VI) and methylene blue

NASA Astrophysics Data System (ADS)

Zhang, Linjiang; Liu, Zhuannian; Fan, Yidan; Fan, Aping; Han, Xiaogang

2018-02-01

In this paper, the semi-coke powder was modified by three kinds of physical or chemical methods and then modified semi-coke was used as adsorbent for removal of Cr6+ and methylene blue (MB) from aqueous solution. The effects of time, dosage and pH on removal rate were investigated using batch experiments. The process of Cr6+ and MB adsorption onto the modified semi-coke powder follows pseudo second-order kinetics. The analysis of SEM and BET showed the Specific surface area of modified semi-coke are 84.92 m2/g, which is higher than that of raw semi-coke powder.

[Methaemoglobinaemia induced by ingestion of alkyl nitrite, "poppers"].

PubMed

Kragsfeldt, Celina Thelberg; Nissen, Christoffer B; Brandt, Frans

2016-08-22

We present a case report of an 18-year-old male who was referred to the emergency department with evidence of methaemoglobinaemia. He presented with classic symptoms with peripheral cyanosis and hypoxia. Arterial blood gas showed a methaemoglobin level of 36%. This was caused by ingestion of alkyl nitrate, a widespread party drug called "poppers". When inhaled it causes euphoria, reduced pain and relaxation of the anal sphincter, but oral use may induce life-threatening methaemoglobinaemia. The treatment of choice is the antidote methylene blue. After treatment the patient regained full recovery and was discharged on the following day. We discuss classic symptoms, diagnosis and treatment of intoxication with methylene blue.

Zinc sulfide quantum dots for photocatalytic and sensing applications

NASA Astrophysics Data System (ADS)

Sergeev, Alexander A.; Leonov, Andrei A.; Zhuikova, Elena I.; Postnova, Irina V.; Voznesenskiy, Sergey S.

2017-09-01

Herein, we report the photocatalytic and sensing applications of pure and Mn-doped ZnS quantum dots. The quantum dots were prepared by a chemical precipitation in an aqueous solution in the presence of glutathione as a stabilizing agent. The synthesized quantum dots were used as effective photocatalyst for the degradation of methylene blue dye. Interestingly, fully degradation of methylene blue dye was achieved in 5 min using pure ZnS quantum dots. Further, the synthesized quantum dots were used as efficient sensing element for methane fluorescent sensor. Interfering studies confirmed that the developed sensor possesses very good sensitivity and selectivity towards methane.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometric analysis of degradation products after treatment of methylene blue aqueous solution with three-dimensionally integrated microsolution plasma

NASA Astrophysics Data System (ADS)

Shirafuji, Tatsuru; Nomura, Ayano; Hayashi, Yui; Tanaka, Kenji; Goto, Motonobu

2016-01-01

Methylene blue can be degraded in three-dimensionally integrated microsolution plasma. The degradation products have been analyzed by matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry to understand the degradation mechanisms. The results of MALDI TOF mass spectrometry have shown that sulfoxide is formed at the first stage of the oxidation. Then, partial oxidation proceeds on the methyl groups left on the sulfoxide. The sulfoxide is subsequently separated to two benzene derivatives. Finally, weak functional groups are removed from the benzene derivatives.

Kinetics and mechanism of dye adsorption on WO3 nanoparticles

NASA Astrophysics Data System (ADS)

Adhikari, Sangeeta; Mandal, Sandip; Sarkar, Debasish; Kim, Do-Heyoung; Madras, Giridhar

2017-10-01

Monoclinic WO3 nanoparticles were synthesized by a simple acid catalyzed co-precipitation reaction. Spherical particles with average size ∼55 nm were confirmed from electron microscopy followed by functional, structural and optical characterizations. The adsorption of methylene blue was examined by using WO3 nanoparticles and the capacity was higher than most of the reported studies. The effect of pH and material loading on adsorption was determined. The mechanism of adsorption was examined by XPS and a detailed explanation of surface phenomena was proposed. Regeneration study was carried and a high stability of heat treated WO3 towards adsorption of methylene blue was observed.

Influence of acid chain length on the properties of TiO2 prepared by sol-gel method and LC-MS studies of methylene blue photodegradation.

PubMed

Bakre, Pratibha V; Volvoikar, Prajesh S; Vernekar, Amit A; Tilve, S G

2016-07-15

Nano-sized titanium dioxide photocatalysts were synthesized by hybrid hydrolytic nonhydrolytic sol-gel method using aliphatic organic acid templates to study the effect of chain length on their properties. X-ray diffraction pattern indicated crystalline anatase phase. The Barrett-Joyner-Halenda surface area measurement gave surface area ranging from 98.4 to 205.5m(2)/g and was found to be dependent on the chain length of the aliphatic acid. The longer chain acids rendered the material with high surface area. The organic acids acted as bidentate ligand and a surfactant in controlling the size and the mesoporosity. The size of the TiO2 nanoparticulate was found to be in the range of 10-18nm. The catalyst prepared by employing long chain acids octanoic acid and palmitic acid had smaller size, narrow pore radius, higher surface area and showed better photocatalytic activity than the commercially available Degussa P25 catalyst for the degradation of methylene blue dye. A new intermediate was identified by tandem liquid chromatography mass spectrometry studies during the degradation of methylene blue solution. Copyright © 2016 Elsevier Inc. All rights reserved.

Plasmon-enhanced photocatalytic activity of Na0.9Mg0.45Ti3.55O8 loaded with noble metals directly observed with scanning Kelvin probe microscopy.

PubMed

Wang, Jing-Zhou; Guo, Ze-Qing; Zhou, Jian-Ping; Lei, Yu-Xi

2018-07-27

The noble metals Au, Ag and Pt were loaded onto Na 0.9 Mg 0.45 Ti 3.55 O 8 (NMTO) using a chemical bath deposition method devised in our recent work for the first time. The composite photocatalysts exhibit more effective photodegradation of methylene blue, due to the Schottky barrier built between NMTO and noble metal. Hot electrons generated during localized surface plasmon processes in metal nanoparticles transfer to the semiconductor, manifesting as a depression of surface potential directly detectable by scanning Kelvin probe microscopy. The key factor responsible for the improved ability of semiconductor-based photocatalysts is charge separation. The most effective weight concentrations of Au, Ag and Pt loaded onto NMTO were found to be 5.00%, 12.6% and 5.55% respectively. NMTO loaded with noble metals shows good photostability and recyclability for the degradation of methylene blue. A possible mechanism for the photodegradation of methylene blue over NMTO loaded with noble metals is proposed. This work highlights the potential application of NMTO-based photocatalysts, and provides an effective method to detect localized surface plasmons.

Adsorption of methylene blue onto activated carbon produced from tea (Camellia sinensis L.) seed shells: kinetics, equilibrium, and thermodynamics studies.

PubMed

Gao, Jun-Jie; Qin, Ye-Bo; Zhou, Tao; Cao, Dong-Dong; Xu, Ping; Hochstetter, Danielle; Wang, Yue-Fei

2013-07-01

Tea (Camellia sinensis L.) seed shells, the main byproduct of the manufacture of tea seed oil, were used as precursors for the preparation of tea activated carbon (TAC) in the present study. A high yield (44.1%) of TAC was obtained from tea seed shells via a one-step chemical method using ZnCl2 as an agent. The Brunauer-Emmett-Teller (BET) surface area and the total pore volumes of the obtained TAC were found to be 1530.67 mg(2)/g and 0.7826 cm(3)/g, respectively. The equilibrium adsorption results were complied with Langmuir isotherm model and its maximum monolayer adsorption capacity was 324.7 mg/g for methylene blue. Adsorption kinetics studies indicated that the pseudo-second-order model yielded the best fit for the kinetic data. An intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step. Thermodynamics studies revealed the spontaneous and exothermic nature of the sorption process. These results indicate that tea seed shells could be utilized as a renewable resource to develop activated carbon which is a potential adsorbent for methylene blue.

Adsorption properties and photocatalytic activity of TiO2/activated carbon fiber composite

NASA Astrophysics Data System (ADS)

Yao, Shuhua; Song, Shuangping; Shi, Zhongliang

2014-06-01

Photocatalysts of titanium dioxide (TiO2) and TiO2/activated carbon fiber (TiO2/ACF) composite were prepared by sol-gel method, followed by calcining the pure TiO2 sols and the TiO2/ACF sols at 500°C for 2 h in a N2 atmosphere, respectively. These photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption-desorption isotherms measurement. Batch experiments were conducted to study the adsorption property of TiO2/ACF composite using methylene blue as adsorbate. The adsorption data obtained from different batch experiments were analyzed using pseudo-second-order kinetic model, the experimental data can be adequately described by the pseudo-second-order equation. The photodecomposition behavior of TiO2/ACF was investigated in aqueous solution using methylene blue as target pollutant. It was found that methylene blue could be removed rapidly from water by TiO2/ACF, the photocatalytic decomposition was obviously improved when the photocatalyst was used. Kinetics analysis revealed that the photocatalytic decomposition reaction can be described well by a first-order rate equation.

A Possible Phenomenon of Persistence in Pseudomonas aeruginosa Treated with Methylene Blue and Red Light.

PubMed

Forte Giacobone, Ana Florencia; Ruiz Gale, Maria Fernanda; Hogert, Elsa Noemí; Oppezzo, Oscar Juan

2016-09-01

Planktonic Pseudomonas aeruginosa cells harvested in stationary phase were exposed to red light in the presence of methylene blue to study the potential occurrence of persistence in bacterial populations submitted to photodynamic antimicrobial therapy. Survival curves revealed the existence of small subpopulations of cells exhibiting increased ability to tolerate the treatment. These subpopulations were detected even using high concentrations of photosensitizer, whether added in a single step or following a fractionated scheme, and when the irradiation medium was modified to delay the photodecomposition of methylene blue. When cells grown from survivors to the treatment were cultured and exposed to red light and dye, their responses were similar to that of the original strain. These results exclude exhaustion of the photosensitizer and selection of resistant mutants as explanations for the features of the survival curves. Cells able to tolerate the treatment were found even when radiation was imparted at a high-dose rate. They exhibit a response typical of persisters, which tolerate antimicrobial agents due to transient and reversible changes in their phenotype, suggesting that persistence is a factor to consider upon evaluating the efficacy of photodynamic antimicrobial therapy. © 2016 The American Society of Photobiology.

Adsorption of methylene blue onto activated carbon produced from tea (Camellia sinensis L.) seed shells: kinetics, equilibrium, and thermodynamics studies*

PubMed Central

Gao, Jun-jie; Qin, Ye-bo; Zhou, Tao; Cao, Dong-dong; Xu, Ping; Hochstetter, Danielle; Wang, Yue-fei

2013-01-01

Tea (Camellia sinensis L.) seed shells, the main byproduct of the manufacture of tea seed oil, were used as precursors for the preparation of tea activated carbon (TAC) in the present study. A high yield (44.1%) of TAC was obtained from tea seed shells via a one-step chemical method using ZnCl2 as an agent. The Brunauer-Emmett-Teller (BET) surface area and the total pore volumes of the obtained TAC were found to be 1 530.67 mg2/g and 0.782 6 cm3/g, respectively. The equilibrium adsorption results were complied with Langmuir isotherm model and its maximum monolayer adsorption capacity was 324.7 mg/g for methylene blue. Adsorption kinetics studies indicated that the pseudo-second-order model yielded the best fit for the kinetic data. An intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step. Thermodynamics studies revealed the spontaneous and exothermic nature of the sorption process. These results indicate that tea seed shells could be utilized as a renewable resource to develop activated carbon which is a potential adsorbent for methylene blue. PMID:23825151

A Novel of Buton Asphalt and Methylene Blue as Dye-Sensitized Solar Cell using TiO2/Ti Nanotubes Electrode

NASA Astrophysics Data System (ADS)

Nurhidayani; Muzakkar, M. Z.; Maulidiyah; Wibowo, D.; Nurdin, M.

2017-11-01

A study of TiO2/Ti nanotubes arrays (NTAs) based on Dye-Sensitized Solar Cell (DSSC) used Asphalt Buton (Asbuton) extract and methylene blue (MB) as a photosensitizer dye has been conducted. The aim of this research is that the Asbuton extract and Methylene Blue (MB) performance as a dye on DSSC solar cells is able to obtain the voltage-currents produced by visible light irradiation. Electrode TiO2/Ti NTAs have been successfully synthesized by anodizing methods, then characterized by using XRD showed that the anatase crystals formed. Subsequently, the morphology showed that the nanotubes formed which has coated by Asbuton extract. The DSSC system was formed by a sandwich structure and tested by using Multimeter Digital with Potentiostat instrument. The characteristics of current (I) and potential (V) versus time indicated that the Asbuton was obtained in a high-performance in 30s of 14,000µV 0.844µA, meanwhile MB dyes were 8,000µV0.573µA. Based on this research, the Asbuton extract from Buton Island-Southeast Sulawesi-Indonesia was potential for natural dyes in DSSC system.

Visible-light photochemical activity of heterostructured core-shell materials composed of selected ternary titanates and ferrites coated by tiO2.

PubMed

Li, Li; Liu, Xuan; Zhang, Yiling; Nuhfer, Noel T; Barmak, Katayun; Salvador, Paul A; Rohrer, Gregory S

2013-06-12

Heterostructured photocatalysts comprised of microcrystalline (mc-) cores and nanostructured (ns-) shells were prepared by the sol-gel method. The ability of titania-coated ATiO3 (A = Fe, Pb) and AFeO3 (A = Bi, La, Y) catalysts to degrade methylene blue in visible light (λ > 420 nm) was compared. The catalysts with the titanate cores had enhanced photocatalytic activities for methylene blue degradation compared to their components alone, whereas the catalysts with ferrite cores did not. The temperature at which the ns-titania shell is crystallized influences the photocatalytic dye degradation. mc-FeTiO3/ns-TiO2 annealed at 500 °C shows the highest reaction rate. Fe-doped TiO2, which absorbs visible light, did not show enhanced photocatalytic activity for methylene blue degradation. This result indicates that iron contamination is not a decisive factor in the reduced reactivity of the titania coated ferrite catalysts. The higher reactivity of materials with the titanate cores suggests that photogenerated charge carriers are more easily transported across the titanate-titanate interface than the ferrite-titanate interface and this provides guidance for materials selection in composite catalyst design.

Structural characteristics of mixed oxides MOx/SiO2 affecting photocatalytic decomposition of methylene blue

NASA Astrophysics Data System (ADS)

Gun'ko, V. M.; Blitz, J. P.; Bandaranayake, B.; Pakhlov, E. M.; Zarko, V. I.; Sulym, I. Ya.; Kulyk, K. S.; Galaburda, M. V.; Bogatyrev, V. M.; Oranska, O. I.; Borysenko, M. V.; Leboda, R.; Skubiszewska-Zięba, J.; Janush, W.

2012-06-01

A series of photocatalysts based on silica (nanoparticulate) supported titania, ceria, and ceria/zirconia were synthesized and characterized by a variety of techniques including surface area measurements, X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential, surface charge density, and photocatalytic behavior toward methylene blue decomposition. Thermal treatment at 600 °C increases the anatase content of the titania based catalysts detected by XRD. Changes in the infrared spectra before and after thermal treatment indicate that at low temperature there are more tbnd Sisbnd Osbnd Titbnd bonds than at high temperature. As these bonds break upon heating the SiO2 and TiO2 separate, allowing the TiO2 anatase phase to form. This results in an increased catalytic activity for the thermally treated samples. Nearly all titania based samples exhibit a negative surface charge density at pH 7 (initial pH of photocatalytic studies) which aids adsorption of methylene blue. The crystallinity of ceria and ceria/zirconia based catalysts are in some cases limited, and in others non-existent. Even though the energy band gap (Eg) can be lower for these catalysts than for the titania based catalysts, their photocatalytic properties are inferior.

Tested Demonstrations.

ERIC Educational Resources Information Center

Fenster, Ariel E.; And Others

1988-01-01

Identifies a technique using methylene blue and glucose to explain a genetically related enzyme shortage causing blue skin in humans. Offers a laser technique to study solubility of silver salts of chloride and chromate. Encourages the use of models and class participation in the study of chirality and enantiomers. (ML)

Smectite clays of Serbia and their application in adsorption of organic dyes

NASA Astrophysics Data System (ADS)

Milošević, Maja; Logar, Mihovil

2014-05-01

Colorants and dyes are currently available in over a 100.000 different species and several biggest industries are using them daily in their manufacture processes (textile, cosmetics, food industry, etc.). Since colorants are easily dissoluble in water they pass through filter membranes without further decomposing and in that manner they end up in the environment. The main goal of this work is to apply certain methods in determining the suitability of individual clay in adsorbing and removing colorants from polluted waters. For this study we have chosen four different raw clays from three regions in Serbia: Svrljig (B), Bogovina (Bo) and Slatina-Ub (C and V) and as colorant - methylene blue dye (MB (MERCK, for analytical purposes)). Experiments where carried out to determine the sample structure (XRD and IR), grain size (granulometry), cationic exchange capacity (CEC via spectrophotometry using MB) and adsorption capabilities (spectrophotometry and fluorimetry using MB). XRD and IR data are showing that the samples are smectite clays where samples B i Bo are mainly montmorillonite while C and V are montmorillonite-illite clays. Granulometric distribution results indicate that samples B i Bo have smaller grain size, less that 1μ (over 60%) whereas the samples C and V are more coarse grained (40% over 20μ). This grain distribution is affecting their specific surface area in the manner that those coarse grained samples have smaller specific surface area. Cationic exchange capacity determined with methylene blue indicate that montmorillonite samples have larger CEC (B = 37 meq/100g, Bo = 50 meq/100g) and montmorillonite-illite samples smaller CEC (V = 5 meq/100g, V = 3 meq/100g). Fluorimetry measurement results gave us a clear distinction between those with higher and smaller adsorption capability. Montmorillonite samples (B and Bo) with higher CEC values and smaller grain size are adsorbing large amounts of methylene blue witch is visible by absence of fluorimetric band corresponding to methylene blue. Montmorillonite-illite samples with smaller CEC values and coarser grain size are adsorbing very small amounts of methylene blue from the suspension which is visible by appearance of the methylene blue band. Untreated, raw smectite clays of Serbia are efficient adsorbent material for removal of dyes from polluted waters. Samples from two regions especially, Bogovina and Svrljig, are showing favorable adsorption results and they are representing good raw materials for purification of waste-waters containing dyes. References: - Jović-Jovičić, N., Milutinović-Nikolić, A., Gržetić, I., Jovanović, D.; Organobentonite as efficient textile dye sorbent; Chem. Eng. Technol. 2008, 31, No. 4, 567-574 - Žunić, M.J., Milutinović-Nikolić, A.D., Jović-Jovičić, N.P., Banković, P.T., Mojović, Z.D., Manojlović, D.D., Jovanović, D.M.; Modified bentonite as adsorbent and catalyst for purification of wastewaters containing dyes; Hem. ind. 2010, 64 ,No. 3, 193-199

Relation between some two- and three-parameter isotherm models for the sorption of methylene blue onto lemon peel.

PubMed

Kumar, K Vasanth; Porkodi, K

2006-12-01

Equilibrium uptake of methylne blue onto lemon peel was fitted to the 2 two-parameter isotherm models namely Freundlich and Langmuir and 3 six-parameter isotherm models namely Redlich-Peterson, Toth, Radke-Prausnitz, Fritz-Schluender, Vieth-Sladek and Sips isotherms by non-linear method. A comparison between two-parameter and three-parameter isotherms was reported. The best fitting isotherm was the Sips isotherm followed by Langmuir isotherm and Redlich-Peterson isotherm equation. Redlich-Peterson isotherm is a special case of Langmuir isotherm when the Redlich-Peterson isotherm constant g was unity. Radke-Prausnitz, Toth, Vieth-Sladek isotherm were the same when the Toth isotherm constant, n(T) and the Radke-Prausnitz isotherm, m(RP) are equal to unity and when the Vieth-Sladek isotherm constant, K(VS) equals zero. The sorption capacity of lemon peel for methylene blue uptake was found to be 29 mg/g.

Preparation and characterization of double layer thin films ZnO/ZnO:Ag for methylene blue photodegradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wibowo, Singgih, E-mail: singgih@st.fisika.undip.ac.id; Sutanto, Heri, E-mail: herisutanto@undip.ac.id

2016-02-08

Double layer (DL) thin films of zinc oxide and silver-doped zinc oxide (ZnO/ZnO:Ag) were deposited on glass substrate by sol-gel spray coating technique. The prepared thin films were subjected for optical and photocatalytic studies. UV-visible transmission spectra shows that the subtitution of Ag in ZnO leads to band gap reduction. The influence of Ag doping on the photocatalytic activity of ZnO for the degradation of methylene blue dye was studied under solar radiation. The light absorption over an extended visible region by Ag ion doping in ZnO film contributed equally to improve the photocatalytic activity up to 98.29%.

Methylene blue as a lignin surrogate in manganese peroxidase reaction systems.

PubMed

Goby, Jeffrey D; Penner, Michael H; Lajoie, Curtis A; Kelly, Christine J

2017-11-15

Manganese peroxidase (MnP) is associated with lignin degradation and is thus relevant to lignocellulosic-utilization technologies. Technological applications require reaction mixture optimization. A surrogate substrate can facilitate this if its susceptibility to degradation is easily monitored and mirrors that of lignin. The dye methylene blue (MB) was evaluated in these respects as a surrogate substrate by testing its reactivity in reaction mixtures containing relevant redox mediators (dicarboxylic acids, fatty acids). Relative rates of MB degradation were compared to available literature reports of lignin degradation under similar conditions, and suggest that MB can be a useful lignin surrogate in MnP systems. Copyright © 2017 Elsevier Inc. All rights reserved.

Microplasma effect on skin scaffold for melanoma cancer treatment

NASA Astrophysics Data System (ADS)

Abdullah, Zulaika; Zaaba, S. K.; Mustaffa, M. T.; Mohamad, C. W. S. R.; Zakaria, A.

2017-03-01

An atmospheric plasma system using Helium gas was developed. The effect of helium plasma treatment on skin scaffold surface was studied by scanning electron microscopy (SEM). The changes of skin scaffold surfaces before and after helium plasma treatment was recorded. The surface of skin scaffold changed with the prolonged of helium plasma treatment time. The depth of helium plasma penetration was studied using methylene blue dye staining method. The methylene blue will detect the presence or absence of an oxygen that was induced from plasma excitation. The presence of the oxygen indicated on the depth of helium plasma penetration. Results showed plasma are able to penetrate 4mm of skin scaffold after 1200 seconds of exposure.

Performance of zeolite ceramic membrane synthesized by wet mixing method as methylene blue dye wastewater filter

NASA Astrophysics Data System (ADS)

Masturi; Widodo, R. D.; Edie, S. S.; Amri, U.; Sidiq, A. L.; Alighiri, D.; Wulandari, N. A.; Susilawati; Amanah, S. N.

2018-03-01

Problem of pollution in water continues in Indonesia, with its manufacturing sector as biggest contributor to economic growth. One out of many technological solutions is post-treating industrial wastewater by membrane filtering technology. We presented a result of our fabrication of ceramic membrane made from zeolite with simple mixing and he. At 5% of (poring agent):(total weight), its permeability stays around 2.8 mD (10‑14m2) with slight variance around it, attributed to the mixture being in far below percolating threshold. All our membranes achieve remarkable above 90% rejection rate of methylene blue as solute waste in water solvent.

Attaching NorA efflux pump inhibitors to methylene blue enhances antimicrobial photodynamic inactivation of Escherichia coli and Acinetobacter baumannii in vitro and in vivo.

PubMed

Rineh, Ardeshir; Bremner, John B; Hamblin, Michael R; Ball, Anthony R; Tegos, George P; Kelso, Michael J

2018-02-24

Resistance of bacteria to antibiotics is a public health concern worldwide due to the increasing failure of standard antibiotic therapies. Antimicrobial photodynamic inactivation (aPDI) is a promising non-antibiotic alternative for treating localized bacterial infections that uses non-toxic photosensitizers and harmless visible light to produce reactive oxygen species and kill microbes. Phenothiazinium photosensitizers like methylene blue (MB) and toluidine blue O are hydrophobic cations that are naturally expelled from bacterial cells by multidrug efflux pumps, which reduces their effectiveness. We recently reported the discovery of a NorA efflux pump inhibitor-methylene blue (EPI-MB) hybrid compound INF55-(Ac)en-MB that shows enhanced photodynamic inactivation of the Gram-positive bacterium methicillin-resistant Staphylococcus aureus (MRSA) relative to MB, both in vitro and in vivo. Here, we report the surprising observation that INF55-(Ac)en-MB and two related hybrids bearing the NorA efflux pump inhibitors INF55 and INF271 also show enhanced aPDI activity in vitro (relative to MB) against the Gram-negative bacteria Escherichia coli and Acinetobacter baumannii, despite neither species expressing the NorA pump. Two of the hybrids showed superior effects to MB in murine aPDI infection models. The findings motivate wider exploration of aPDI with EPI-MB hybrids against Gram-negative pathogens and more detailed studies into the molecular mechanisms underpinning their activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Preparation and characterization of poly(AA co PVP)/PGS composite and its application for methylene blue adsorption.

PubMed

Yang, Cai-xia; Lei, Lei; Zhou, Peng-xin; Zhang, Zhe; Lei, Zi-qiang

2015-04-01

Poly (AA co PVP)/PGS (PAPP) composite adsorbent was prepared by radical polymerization from Acrylic acid (AA), Polyvinylpyrrolidone (PVP) and Palygorskite (PGS), using N,N-methylenebisacrylamide (MBA) as cross-linker and potassium persulfate (KPS) as initiator. The PAPP was characterized with Fourier transform infrared (FT-IR), thermogravimetric analysis (TG), scanning electron microscope (SEM) and transmission electron microscopy (TEM). PAPP was used as adsorbent for the removal of methylene blue from aqueous solutions. The influences of pH, adsorption temperature and adsorption time on the adsorption properties of the composite to the dye were also investigated. Meanwhile, the adsorption rate data and adsorption equilibrium date were analyzed based on the pseudo-first-order and pseudo-second-order kinetic model, Langmuir and Freundlich isotherm models, respectively. The results indicating that the kinetic behavior better fit with the pseudo-second-order kinetic model. The maximum equilibrium adsorption capacity (q(m)) is 1815 mg/g at 289 K. The isotherm behavior can be explained by the Langmuir isotherm models. The activation energy was also evaluated for the removal of methylene blue onto PAPP. These results demonstrate that this composite material could be used as a good adsorbent for the removal of cationic dyes from wastewater. Copyright © 2014 Elsevier Inc. All rights reserved.

3D Oxidized Graphene Frameworks: An Efficient Adsorbent for Methylene Blue

NASA Astrophysics Data System (ADS)

Pandey, Abhishek; Deb, Madhurima; Tiwari, Shreya; Pawar, Pranav Bhagwan; Saxena, Sumit; Shukla, Shobha

2018-04-01

Extraordinary properties of graphene and its derivatives have found application in varied areas such as energy, electronics, optical devices and sensors, to name a few. Large surface area along with specialized functional groups make these materials attractive for removal of dye molecules in solution via adsorption. Industrial effluents contain large amounts of toxic chemicals resulting in pollution of water bodies, which pose environmental hazards in general. Here we report application of 3D oxidized graphene frameworks in the efficient removal of cationic dye molecules such as methylene blue via adsorption. Systematic parametric studies investigating the effect of the initial dye concentration, pH and contact time have been performed. Spectroscopic analysis of the filtrate suggests that tortuous paths in 3D oxidized graphene frameworks result in efficient removal of dye molecules due to enhanced interaction. The hydroxyl groups retained in these 3D oxidized graphene frameworks facilitate adsorption of the dye molecules while passing through the adsorbent. pH studies suggest that maximum removal efficiency for methylene blue was achieved at pH value of 9. The results suggest that these 3D oxidized graphene frameworks can be used for purification of large volumes of contaminated water from cationic dyes in waste water treatment plants.

Enhanced photocatalytic activity of Te-doped Bi2MoO6 under visible light irradiation: Effective separation of photogenerated carriers resulted from inhomogeneous lattice distortion and improved electron capturing ability

NASA Astrophysics Data System (ADS)

Chen, Shuguang; Li, Yuhan; Wu, Zixu; Wu, Baoxin; Li, Haibin; Li, Fujin

2017-05-01

Te-doped Bi2MoO6 photocatalyst was hydrothermally synthesized, and nonmetal atoms Te were homogeneously incorporated into Bi2MoO6 lattice with the substitution of Te4+ to Mo6+. With increasing Te-doping concentration in Bi2MoO6, no detectable band-gap narrowing but more and more severe inhomogeneous lattice distortions were determined. The activity of Bi2MoO6 photocatalyst was evaluated through methylene blue degradation under visible light irradiation (λ>410 nm) and was greatly enhanced by Te-doping. When Te-doped Bi2MoO6 was synthesized at Te/Mo molar ratio of 7.5%, a maximum first-order rate constant of methylene blue degradation was obtained. The inhomogeneous lattice distortion generated an internal dipole moment, and the holes generated with the substitution of Te4+ to Mo6+ acted as the capturing centers of photogenerated electrons, thus the effective separation of photogenerated carriers was facilitated to result in a relatively high concentration of holes on the surface of Te-doped Bi2MoO6 to be favorable for the efficient methylene blue degradation.

A cadaveric study to determine the minimum volume of methylene blue to completely color the nerves of brachial plexus in cats. An update in forelimb and shoulder surgeries.

PubMed

Mencalha, Rodrigo; Fernandes, Neide; Sousa, Carlos Augusto dos Santos; Abidu-Figueiredo, Marcelo

2014-06-01

To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats. Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch. The measurement of the effective area was indicated by the impregnation of MB. Nerves were divided into four segments from the origin at the spinal level until the insertion into the thoracic limb muscles. The blocks were considered effective only when all the nerves were strongly or totally colored. Volumes of 2, 3 and 4 ml were considered insufficient suggesting a failed block, however, volumes of 5 and 6 ml were associated with a successful block. The injection of methylene blue, in a volume of 6 ml, completely colored the brachial plexus. At volumes of 5 and 6 ml the brachial plexus blocks were considered a successful regional block, however, volumes of 2, 3 and 4 ml were considered a failed regional block.

Linear and non-linear regression analysis for the sorption kinetics of methylene blue onto activated carbon.

PubMed

Kumar, K Vasanth

2006-10-11

Batch kinetic experiments were carried out for the sorption of methylene blue onto activated carbon. The experimental kinetics were fitted to the pseudo first-order and pseudo second-order kinetics by linear and a non-linear method. The five different types of Ho pseudo second-order expression have been discussed. A comparison of linear least-squares method and a trial and error non-linear method of estimating the pseudo second-order rate kinetic parameters were examined. The sorption process was found to follow a both pseudo first-order kinetic and pseudo second-order kinetic model. Present investigation showed that it is inappropriate to use a type 1 and type pseudo second-order expressions as proposed by Ho and Blanachard et al. respectively for predicting the kinetic rate constants and the initial sorption rate for the studied system. Three correct possible alternate linear expressions (type 2 to type 4) to better predict the initial sorption rate and kinetic rate constants for the studied system (methylene blue/activated carbon) was proposed. Linear method was found to check only the hypothesis instead of verifying the kinetic model. Non-linear regression method was found to be the more appropriate method to determine the rate kinetic parameters.

Potential Biosorbent Derived from Calligonum polygonoides for Removal of Methylene Blue Dye from Aqueous Solution

PubMed Central

Nasrullah, Asma; Khan, Hizbullah; Khan, Amir Sada; Man, Zakaria; Muhammad, Nawshad; Khan, Muhammad Irfan; Abd El-Salam, Naser M.

2015-01-01

The ash of C. polygonoides (locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R 2) of 0.999. The study revealed that C. polygonoides ash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution. PMID:25705714

Daylight photodynamic therapy with methylene blue in plane warts: a randomized double-blind placebo-controlled study.

PubMed

Fathy, Ghada; Asaad, Marwa Kamal; Rasheed, Haval Mohamad

2017-07-01

Conventional photodynamic therapy is associated with inconveniently long clinic visits and discomfort during therapy. Daylight-photodynamic therapy (DL-PDT) is an effective treatment, nearly pain free and more convenient for both the clinics and patients. There are no published studies of methylene blue (MB) as a photosensitizer (PS) used in DL-PDT. Forty patients had multiple plane warts; 20 patients were subjected to DL-PDT with topical 10% methylene blue gel, and 20 patients were subjected to DL-PDT with hematoxylin (placebo). Improvement was evaluated by change of the number of warts and the dermoscope picture. A total of 20 (100%) patients in group II showed no response to placebo, 13 patients (65%) in group I showed complete clearance, 2 (10%) patients showed a good response, and 5 (25%) patients had poor response to treatment (P < 0.01). No serious side effects and patients tolerated the pain well. No relapse was detected during the follow-up period (12 months). Daylight exposure was not monitored with a dosimeter. Daylight-PDT using MB is safe, easy to carry out, economic, effective, acceptable cosmetic results with no recurrence, convenient especially for children and nearly painless treatment. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Solvothermal synthesis of V{sub 4}O{sub 9} flake-like morphology and its photocatalytic application in the degradation of methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chine, M.K.; Sediri, F., E-mail: faouzi.sediri@ipeit.rnu.tn; Faculté des Sciences de Tunis, Université, Tunis-Elmanar, 2092 Elmanar, Tunis

2012-11-15

Highlights: ► Flake-like nanocrystalline V{sub 4}O{sub 9} was synthesized by a solvothermal route. ► Photocatalytic activity has been evaluated by the degradation of methylene blue under visible light irradiation. ► V{sub 4}O{sub 9} nanoflakes exhibited much higher photocatalytic activity two times higher than the bulk V{sub 2}O{sub 5}. -- Abstract: Flake-like nanocrystalline V{sub 4}O{sub 9} has been successfully synthesized by solvothermal process using V{sub 2}O{sub 5} as vanadium source and phenolphthalein as a reducing agent and a structure-directing template. Techniques X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and ultraviolet–visible (UV–vis) spectroscopy have been used tomore » characterize the structure, the morphology and the composition of the material. The photocatalytic activity of the material has been evaluated by the degradation of methylene blue under visible light irradiation. As a result, after the lapse of 150 min, around 93.54% bleaching was observed, with V{sub 4}O{sub 9} nanoflakes yielding more photodegradation compared to that of bulk V{sub 2}O{sub 5}. This presents a degradation percentage of about 44.67%.« less

Impedimetric genosensor for detection of hepatitis C virus (HCV1) DNA using viral probe on methylene blue doped silica nanoparticles.

PubMed

Singhal, Chaitali; Ingle, Aviraj; Chakraborty, Dhritiman; Pn, Anoop Krishna; Pundir, C S; Narang, Jagriti

2017-05-01

An impedimetric genosensor was fabricated for detection of hepatitis C virus (HCV) genotype 1 in serum, based on hybridization of the probe with complementary target cDNA from sample. To achieve it, probe DNA complementary to HCVgene was immobilized on the surface of methylene blue (MB) doped silica nanoparticles MB@SiNPs) modified fluorine doped tin oxide (FTO) electrode. The synthesized MB@SiNPs was characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) pattern. This modified electrode (ssDNA/MB@SiNPs/FTO) served both as a signal amplification platform (due to silica nanoparticles (SiNPs) as well as an electrochemical indicator (due to methylene blue (MB)) for the detection of the HCV DNA in patient serum sample. The genosensor was optimized and evaluated. The sensor showed a dynamic linear range 100-10 6 copies/mL, with a detection limit of 90 copies/mL. The sensor was applied for detection of HCV in sera of hepatitis patient and could be renewed. The half life of the sensor was 4 weeks. The MB@SiNPs/FTO electrode could be used for preparation of other gensensors also. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of eustachian tube function in tympanoplasty.

PubMed

Prasad, Kishore Chandra; Hegde, Mahesh Chandra; Prasad, Sampath Chandra; Meyappan, Hari

2009-06-01

A clinically useful test for eustachian tube function (ETF) is still lacking. Here we plan to evaluate the mucociliary function of the ET by saccharin and methylene blue test, and compare the outcome of surgery with normal and abnormal ET functions. Case series with planned data collection. Department of Otolaryngology-Head and Neck Surgery, Kasturba Medical College, Mangalore (Manipal University), a tertiary care center in South India. This study comprised 86 patients diagnosed with mucosal chronic otitis media in quiescent/inactive stage. All were subjected to a detailed clinical examination and investigations. Preoperative evaluation of ETF was compared with postoperative outcome of surgery, and the results were analyzed. The saccharin test and methylene blue dye test had a good correlation in evaluating ETF. The mean value for saccharin perception time and the clearance time for methylene blue were 17.5 and 8.1 minutes, respectively. ETF was best in anterior, worst among posterior, and intermediate in subtotal perforations. Type 1 tympanoplasty was successful in 94 percent with normal ETF and in 68 percent with partial dysfunction. The saccharin test is a simple, cost-effective, and valuable diagnostic tool to assess the mucociliary function of the ET. The outcome of middle ear surgery would be a success in normal ETF, whereas in partial dysfunction the outcome need not necessarily be a failure.

Use of one- and two-mediator systems for developing a BOD biosensor based on the yeast Debaryomyces hansenii.

PubMed

Zaitseva, A S; Arlyapov, V A; Yudina, N Yu; Alferov, S V; Reshetilov, A N

2017-03-01

We investigated the use of one- and two-mediator systems in amperometric BOD biosensors (BOD, biochemical oxygen demand) based on the yeast Debaryomyces hansenii. Screening of nine mediators potentially capable of electron transfer - ferrocene, 1,1'-dimethylferrocene, ferrocenecarboxaldehyde, ferroceneacetonitrile, neutral red, 2,6-dichlorophenolindophenol, thionine, methylene blue and potassium ferricyanide - showed only ferrocene and neutral red to be efficient electron carriers for the eukaryotes studied. Two-mediator systems based on combinations of the investigated compounds were used to increase the efficiency of electron transfer. The developed two-mediator biosensors exceeded their one-mediator analogs by their characteristics. The most preferable two-mediator system for developing a BOD biosensor was a ferrocene-methylene blue combination that ensured a satisfactory long-time stability (43 days), selectivity, sensitivity (the lower limit of the determined BOD 5 concentrations, 2.5mg О 2 /dm 3 ) and speed (assay time for one sample, not greater than 10min) of BOD determination. Analysis of water samples showed that the use of a ferrocene-methylene blue two-mediator system and the yeast D. hansenii enabled registration of data that highly correlated with the results of the standard method (R=0.9913). Copyright © 2017 Elsevier Inc. All rights reserved.

Comparing the Properties of Electrochemical-Based DNA Sensors Employing Different Redox Tags

PubMed Central

Kang, Di; Zuo, Xiaolei; Yang, Renqiang; Xia, Fan; Plaxco, Kevin W.; White, Ryan J.

2009-01-01

Many electrochemical biosensor approaches developed in recent years utilize redox labeled (most commonly methylene blue or ferrocene) oligonucleotide probes site-specifically attached to an interrogating electrode. Sensors in this class have been reported employing a range of probe architectures, including single- and double-stranded DNA, more complex DNA structures, DNA and RNA aptamers and, most recently, DNA-small molecule chimeras. Signaling in this class of sensors is generally predicated on binding-induced changes in the efficiency with which the covalently attached redox label transfers electrons with the interrogating electrode. Here we have investigated how the properties of the redox tag affect the performance of such sensors. Specifically, we compare the differences in signaling and stability of electrochemical DNA sensors (E-DNA sensors) fabricated using either ferrocene or methylene blue as the signaling redox moiety. We find that while both tags support efficient E-DNA signaling, ferrocene produces slightly improved signal gain and target affinity. These small advantages, however, come at a potentially significant price: the ferrocene-based sensors are far less stable than their methylene blue counterparts, particularly with regards to stability to long-term storage, repeated electrochemical interrogations, repeated sensing/regeneration iterations, and employment in complex sample matrices such as blood serum. PMID:19810694

Performance of photocatalyst based carbon nanodots from waste frying oil in water purification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aji, Mahardika Prasetya, E-mail: mahardika190@gmail.com; Wiguna, Pradita Ajeng; Susanto,

Carbon Nanodots (C-Dots) from waste frying oil could be used as a photocatalyst in water purification with solar light irradiation. Performance of C-Dots as a photocatalyst was tested in the process of water purification with a given synthetic sewage methylene blue. The tested was also conducted by comparing the performance C-Dots made from frying oil, waste fryng oil as a photocatalyst and solution of methylene blue without photocatalyst C-Dots. Performance of C-Dots from waste frying oil were estimated by the results of absorbance spectrum. The results of measurement absorbance spectrum from the process of water purification with photocatalyst C-Dots showedmore » that the highest intensity at a wavelength 664 nm of methylene blue decreased. The test results showed that the performance of photocatalyst C-Dots from waste frying oil was better in water purification. This estimated that number of particles C-dots is more in waste frying oil because have experieced repeated the heating process so that the higher particles concentration make the photocatalyst process more effective. The observation of the performance C-Dots from waste frying oil as a photocatalyst in the water purification processes become important invention for solving the problems of waste and water purification.« less

What Is Happening when the Blue Bottle Bleaches: An Investigation of the Methylene Blue-Catalyzed Air Oxidation of Glucose

ERIC Educational Resources Information Center

Anderson, Laurens; Wittkopp, Stacy M.; Painter, Christopher J.; Liegel, Jessica J.; Schreiner, Rodney; Bell, Jerry A.; Shakhashiri, Bassam Z.

2012-01-01

An investigation of the Blue Bottle Experiment, a well-known lecture demonstration reaction involving the dye-catalyzed air oxidation of a reducing sugar in alkaline solution, has delineated the sequence of reactions leading to the bleaching of the dye, the regeneration of color, and so forth. Enolization of the sugar is proposed as a key step in…

Submucosal tunneling endoscopic resection using methylene-blue guidance for cardial subepithelial tumors originating from the muscularis propria layer.

PubMed

Mao, X-L; Ye, L-P; Zheng, H-H; Zhou, X-B; Zhu, L-H; Zhang, Y

2017-04-01

Submucosal tunneling endoscopic resection (STER) of subepithelial tumors (SETs) originating from the muscularis propria (MP) layer in the cardia is rarely performed due to the difficulty of creating a submucosal tunnel for resection. The aim of this study is to evaluate the feasibility of STER using methylene-blue guidance for SETs originating from the MP layer in the cardia. From January 2012 to December 2014, 56 patients with SETs originating from the MP layer in the cardia were treated with STER using methylene-blue guidance. The complete resection rate and adverse event rate were the main outcome measurements. Successful complete resection by STER was achieved in all 56 cases (100%). The median size of the tumor was 1.8 cm. Nine patients (15.3%) had adverse events including subcutaneous emphysema, pneumoperitoneum, pneumothorax, and pleural effusion. These nine patients recovered successfully after conservative treatment without endoscopic or surgical intervention. No residual or recurrent tumors were detected in any patient during the follow-up period (median, 25 months). The adverse event rate was significantly higher for tumors originating in the deeper MP layers (46.7%) than in the superficial MP layers (4.9%) (P < 0.05), differed significantly according to tumor size (5.4% for tumors < 2.0 cm vs. 36.8% for tumors ≥ 2.0 cm; P < 0.05), and also differed significantly in relation to the tumor growth pattern (4.1% for the intraluminal growth vs. 100% for the extraluminal growth; P < 0.001). STER using methylene-blue guidance appears to be a feasible method for removing SETs originating from the MP layer in the cardia. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The Structural, Photocatalytic Property Characterization and Enhanced Photocatalytic Activities of Novel Photocatalysts Bi2GaSbO7 and Bi2InSbO7 during Visible Light Irradiation

PubMed Central

Luan, Jingfei; Shen, Yue; Li, Yanyan; Paz, Yaron

2016-01-01

In order to develop original and efficient visible light response photocatalysts for degrading organic pollutants in wastewater, new photocatalysts Bi2GaSbO7 and Bi2InSbO7 were firstly synthesized by a solid-state reaction method and their chemical, physical and structural properties were characterized. Bi2GaSbO7 and Bi2InSbO7 were crystallized with a pyrochlore-type structure and the lattice parameter of Bi2GaSbO7 or Bi2InSbO7 was 10.356497 Å or 10.666031 Å. The band gap of Bi2GaSbO7 or Bi2InSbO7 was estimated to be 2.59 eV or 2.54 eV. Compared with nitrogen doped TiO2, Bi2GaSbO7 and Bi2InSbO7, both showed excellent photocatalytic activities for degrading methylene blue during visible light irradiation due to their narrower band gaps and higher crystallization perfection. Bi2GaSbO7 showed higher catalytic activity compared with Bi2InSbO7. The photocatalytic degradation of methylene blue followed by the first-order reaction kinetics and the first-order rate constant was 0.01470 min−1, 0.00967 min−1 or 0.00259 min−1 with Bi2GaSbO7, Bi2InSbO7 or nitrogen doped TiO2 as a catalyst. The evolution of CO2 and the removal of total organic carbon were successfully measured and these results indicated continuous mineralization of methylene blue during the photocatalytic process. The possible degradation scheme and pathway of methylene blue was also analyzed. Bi2GaSbO7 and Bi2InSbO7 photocatalysts both had great potential to purify textile industry wastewater. PMID:28773922

Suppression of cucurbit scab on cucumber leaves by photodynamic dyes

USDA-ARS?s Scientific Manuscript database

The goal of this study was to test the ability of the photodynamic dyes bengal rose, toluidine blue, and methylene blue, to protect systemically cucumber plants from cucurbit scab. At the stage of one true leaf, water or aqueous solutions of the dyes were applied to the leaf as droplets. When the se...

Preparation of activated carbons from unburnt coal in bottom ash with KOH activation for liquid-phase adsorption.

PubMed

Wu, Feng-Chin; Wu, Pin-Hsueh; Tseng, Ru-Ling; Juang, Ruey-Shin

2010-05-01

In this work, unburnt coal (UC) in bottom ash from coal-fired power plants was soaked in KOH solution and activated for 1 h at 780 degrees C. The yield of activated carbons varied from 47.8 to 54.8% when the KOH/UC weight ratio changed from 2 to 4. Pore properties of these activated carbons including the BET surface area, pore volume, pore size distribution, and pore diameter were characterized based on N(2) adsorption isotherms. It was shown that the isotherms for the adsorption of methylene blue, acid blue 74, and 4-chlorophenol from aqueous solutions on these activated carbons at 30 degrees C were well fitted by the Langmuir equation (correlation coefficient r(2) > 0.9968). The adsorption capacities of methylene blue, acid blue 74, and 4-chlorophenol were obtained to be 2.40-2.88, 0.57-1.29, and 2.34-5.62 mmol/g, respectively. Moreover, the adsorption kinetics could be suitably described by the Elovich equation. Copyright 2010. Published by Elsevier Ltd.

Precursor effects on the morphology and crystallinity of manganese oxides and their catalytic application for methylene blue degradation

NASA Astrophysics Data System (ADS)

Awaluddin, Amir; Agustina, Mutia; Aulia, Rizki Rilda; Muhdarina

2017-03-01

The cryptomelane-type manganese oxide catalysts have been prepared by sol-gel method based on the redox reaction between potassium permanganate and glucose or oxalic acid. These catalysts belong to a class of porous manganese oxides known as octahedral molecular sieves (OMS). The SEM results indicated that the marked difference between the morphology of the cyptomelanes produced from glucose and oxalic acid. The glucose precursor produces cotton-shaped morphology, whereas the oxalic acid precursor leads to the formation of the disk-like appearances. The XRD results indicated that the glucose precursor produces more crystalline cryptomelane than that of oxalic acid. The effect of catalyst dosage on methyelene blue degradation was evaluated. Dye-decomposing activity was proportional to the amount of catalyst used, increasing of the catalyst amount leads to higher degradation of methyelene blue at short period of reaction. With different crystalline structures and morphology appearances of the cyptomelanes, however, the total degradation of methylene blue is relatively the same at 120 minute of reaction time with catalyst amount of 100 mg.

The affect of low-coherent light on microbial colony forming ability and morphology of some gram-positive and gram-negative bacteria

NASA Astrophysics Data System (ADS)

Popov, Denis E.; Tuchina, Elena S.; Chernova, Julia A.; Podshibyakin, Dmitry; Rudik, Dmitry V.; Samsonova, Maria; Gromov, Igor; Tuchin, Valery V.

2005-06-01

Gram-negative E. coli, gram-positive facultative anaerobe cocci Staphylococcus lugdensis, Micrococcus halobius, and Stomatococcus mucilaginosus as subjects of study were chosen. LEDs with spectrum maxima at 405 nm (without any exogenous sensitizer) and 660 nm (in conjunction with methylene blue) and power densities of 23 mW/cm2 and 5.7 mW/cm2 accordingly as continuous light sources were chosen. Photosensitized light's affect by methylene blue was studied on E. coli only. The original scheme of experiment set up was developed. It permits one to increase expositions quantity in each experiment for more certain trend's construction over dose curves and decrease parasite flora sowing. As a result of accomplished studies it was established that blue low-coherent light have unalike weak light's dose depending suppressing effect on cocci whereas red low-coherent light have a moderate dose-depended suppressing effect at low irradiation doses and a moderate dose-depended stimulating effect at high irradiation doses on sensitized by MeBlue E. coli. For all ofthis, but Staphylococcus morphology changes were observed.

Construction of High Activity Titanium Dioxide Crystal Surface Heterostructures and Characterization of Its Basic Properties

NASA Astrophysics Data System (ADS)

Wang, Chunxiao; Li, DanQi; Shen, Tingting; Lu, Cheng; Sun, Jing; Wang, Xikui

2018-01-01

Heterogeneous photocatalytic materials, which combine the advantages of photocatalytic materials and heterojunction, have been developed rapidly in the field of environmental pollution control. In this paper, TiO2 surface heterojunction catalysts with different catalytic activity were prepared by controlling the amount of HF, and their XRD characterization was also carried out. In addition, the optimum amount of HF was determined by photocatalytic degradation of simulated dye wastewater by methylene blue solution. And the optimal amount of catalyst and the optimal pH reaction conditions for degradation experiments were used to screen the highly reactive titania surface heterojunction system and its optimum application conditions. It provides the possibility of application in the degradation of industrial wastewater and environmental treatment.

Utilization of biogenic tea waste silver nanoparticles for the reduction of organic dyes

NASA Astrophysics Data System (ADS)

Kaur, H.; Jaryal, N.

2018-05-01

Eco-friendly synthesis of nanoparticles is the need of the society today. Present study has been undertaken to investigate the greener approach for the preparation of medicinally and chemically important nanoparticles. Tea waste has been taken to synthesis silver nanoparticles. The nanoparticles are characterized by x-ray Diffraction, and Transmission Emission Microscopy studies. The particle size varied from 2 to 34 nm. These silver nanoparticles were evaluated for their reducing activity against four organic dyes viz crystal violet, methylene blue, Congo red and brilliant green. The particles exhibited good catalytic activity against crystal violet, methylene blue and brilliant green but no activity was visible for Congo red. Furthermore, AgNPs shows very promising and prominent antioxidant activity.

Water Treatment Using Plasma Discharge with Variation of Electrode Materials

NASA Astrophysics Data System (ADS)

Chanan, N.; Kusumandari; Saraswati, T. E.

2018-03-01

This research studied water treatment using plasma discharge. Plasma generated in this study produced active species that played a role in organic compound decomposition. The plasma reactor consisted of two needle electrodes made from stainless steel, tungsten, aluminium and grafit. It placed approximately 2 mm above the solution and connected with high-AC voltage. A solution of methylene blue used as an organic solution model. Plasma treatment times were 2, 4, 6, 8 and 10 min. The absorbance, temperature and pH of the solution were measured before and after treatment using various electrodes. The best electrode used in plasma discharging for methylene blue absorbance reduction was the graphite electrode, which provided the highest degradation efficiency of 98% at 6 min of treatment time.

Optimization of methylene blue removal by stable emulsified liquid membrane using Plackett–Burman and Box–Behnken designs of experiments

PubMed Central

Djenouhat, Meriem; Bendebane, Farida; Bahloul, Lynda; Samar, Mohamed E. H.

2018-01-01

The stability of an emulsified liquid membrane composed of Span80 as a surfactant, D2EHPA as an extractant and sulfuric acid as an internal phase was first studied according to different diluents and many operating parameters using the Plackett–Burman design of experiments. Then the removal of methylene blue from an aqueous solution has been carried out using this emulsified liquid membrane at its stability conditions. The effects of operating parameters were analysed from the Box–Behnken design of experiments. The optimization of the extraction has been realized applying the response surface methodology and the results showed that the dye extraction yielding 98.72% was achieved at optimized conditions. PMID:29515841

Report of the M16 Rifle Review Panel. Volume 10, Appendix 9. Audit Trail of Chief of Staff, Army Actions and Decisions Concerning the M16

DTIC Science & Technology

1968-06-01

CHEMORECEPTORS CHEMOTAXIS CHEMOTHERAPEUTIC AGENTS CHEMOTHERAPY CHERRIES CHESAPEAKE BAY CHI SQUARE TEST CHICKENS CHIKUNGUNYA VIRUS CHILDREN CHILE...METHYL SULFOXIDE METHYLAL METHYLAMINE METHYLATION METHYLENE BLUE METHYLENES METRIC SYSTEM METROLOGY MEXICO MEXICO GULF MICA MICA CAPACITORS...NEUTRON TRANSPORT THEORY NEUTRONS NEVADA NEW BRUNSWICK NEW ENGLAND NEW GUINEA NEW HAMPSHIRE NEW JERSEY NEW MEXICO NEW YORK NEW YORK CITY

[Poisoning with "poppers", a rare cause of methemoglobinemia observed in emergency cases].

PubMed

Staïkowsky, F; Perret, A; Péviriéri, F; Zanker, C; Zerkak, D; Pelloux, P; Danhiez, F

1997-10-04

Methemoglobulinemia should be entertained as a differential diagnosis in patients with cyanosis. Recently in France there has been an increase in the number of cases of acquired methemoglobulinemia due to inhalation of poppers. Four patients were admitted to the emergency room of a Paris hospital in a state of unconsciousness with cyanosis. All four patients had inhaled poppers shortly before admission. The clinical course was rapidly favorable after intravenous infusion of methylene blue in 3 cases. Poppers are inorganic aliphatic nitrites used for their relaxing effect on smooth muscle and for their aphrodisiac effect. One poorly recognized effect is the development of methemoglobulinemia. Tissue hypoxia results because methemoglobulin cannot bind oxygen, leading to a brown or blue coloration of the blood. Methemoglobulin usually results from exposure to a wide variety of oxidizing compounds including certain drugs. Methylene blue is the specific treatment for symptomatic methemoglobulinemia. These four cases emphasize the toxic effect of products sold in sex shops and calls attention to the life-threatening risks involved.

Improving the performance of methylene blue sensitized photopolymer by doping with nickel ion

NASA Astrophysics Data System (ADS)

Aswathy, G.; Rajesh, C. S.; Sreekumar, K.; Joseph, R.; Kartha, C. Sudha

2016-05-01

Holographic performance of an economically cheap metal ion doped photopolymer material is presented. We investigated the effect of incorporation of nickel ion into the methylene blue sensitized poly (vinyl alcohol)/acrylamide (MBPVA/AA) photopolymer system. The composition and preliminary characterization of the developed photopolymer material is reported. The presence of nickel ion improves the diffraction efficiency, stability of the material and it operates in a wide range of spatial frequencies (550-2000 lines/mm) at exposure energy of 100 mJ/cm2. When nickel ion concentration was 0.01 mM, maximum diffraction efficiency of 84% at exposure energy of 100 mJ/cm2 with spatial frequency 1335 lines/mm could be achieved for gratings recorded using wavelength of 632.8 nm. The material showed panchromaticity with more than 70% diffraction efficiency in both blue and green regions. Effects of humidity and temperature on the stored gratings were studied by keeping films in different environmental conditions. Suitability of recording large area holograms was also explored.

Adsorption of Methylene Blue, Bromophenol Blue, and Coomassie Brilliant Blue by α-chitin nanoparticles

PubMed Central

Dhananasekaran, Solairaj; Palanivel, Rameshthangam; Pappu, Srinivasan

2015-01-01

Expelling of dyestuff into water resource system causes major thread to the environment. Adsorption is the cost effective and potential method to remove the dyes from the effluents. Therefore, an attempt was made to study the adsorption of dyestuff (Methylene Blue (MB), Bromophenol Blue (BPB) and Coomassie Brilliant Blue (CBB)) by α-chitin nanoparticles (CNP) prepared from Penaeus monodon (Fabricius, 1798) shell waste. On contrary to the most recognizable adsorption studies using chitin, this is the first study using unique nanoparticles of ⩽50 nm used for the dye adsorption process. The results showed that the adsorption process increased with increase in the concentration of CNP, contact time and temperature with the dyestuff, whereas the adsorption process decreased with increase in the initial dye concentration and strong acidic pH. The results from Fourier transform infrared (FTIR) spectroscopy confirmed that the interaction between dyestuff and CNP involved physical adsorption. The adsorption process obeys Langmuir isotherm (R2 values were 0.992, 0.999 and 0.992 for MB, BPB and CBB, and RL value lies between 0 and 1 for all the three dyes) and pseudo second order kinetics (R2 values were 0.996, 0.999 and 0.996 for MB, BPB and CBB) more effectively. The isotherm and kinetic models confirmed that CNP can be used as a suitable adsorbent material for the removal of dyestuff from effluents. PMID:26843977

Photochemical quenching of aqueous methylene blue by N, Nb co-doped TiO2 nanomaterials under visible light: a confirmatory UV/LC-MS study

NASA Astrophysics Data System (ADS)

Gupta, Kamini; Pandey, Ashutosh; Singh, R. P.

2017-12-01

Nanodimensional un-doped, Nb doped, N doped and N,Nb co-doped TiO2 particles have been prepared by the sol-gel procedure. Phase identification of the anatase particles was done by X-ray powder diffraction and Deby-Scherrer calculations revealed their particle sizes to range from 20 to 30 nm. The band gap energies of the samples were measured by UV-Vis-diffuse reflectance (UV-DRS) spectra. While un-doped TiO2 showed wide optical absorption in the UV region. The co-doped TiO2 particles exhibited narrow band gaps of ~2.7 eV, which showed absorption in the visible region. A decline in charge carrier recombination rates in the prepared samples was confirmed through photoluminescence (PL). The morphological appearances of the particles have been examined by scanning electron microscopy. X-ray photoelectron spectroscopy (XPS) of the samples confirmed the incorporations of N and Nb into the TiO2 matrices. The photocatalytic efficiencies of the prepared particles have been determined by the degradation of the non-biodegradable dye methylene blue (MB) under electromagnetic radiation. The co-doped sample showed superior photocatalytic activity under the visible light (λ  >  400) over the other samples. Photochemical quenching of aqueous MB was further analysed by UV/LC-MS which confirmed the attenuation of methylene blue.

Modeling methylene blue aggregation in acidic solution to the limits of factor analysis.

PubMed

Golz, Emily K; Vander Griend, Douglas A

2013-01-15

Methylene blue (MB(+)), a common cationic thiazine dye, aggregates in acidic solutions. Absorbance data for equilibrated solutions of the chloride salt were analyzed over a concentration range of 1.0 × 10(-3) to 2.6 × 10(-5) M, in both 0.1 M HCl and 0.1 M HNO(3). Factor analyses of the raw absorbance data sets (categorically a better choice than effective absorbance) definitively show there are at least three distinct molecular absorbers regardless of acid type. A model with monomer, dimer, and trimer works well, but extensive testing has resulted in several other good models, some with higher order aggregates and some with chloride anions. Good models were frequently indistinguishable from each other by quality of fit or reasonability of molar absorptivity curves. The modeling of simulated data sets demonstrates the cases and degrees to which signal noise in the original data obscure the true model. In particular, the more mathematically similar (less orthogonal) the molar absorptivity curves of the chemical species in a model are, the less signal noise it takes to obscure the true model from other potentially good models. Unfortunately, the molar absorptivity curves in dye aggregation systems like that of methylene blue tend to be sufficiently similar so as to lead to the obscuration of models even at the noise levels (0.0001 ABS) of typical benchtop spectrophotometers.

Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

PubMed Central

Felgenträger, Ariane; Maisch, Tim; Dobler, Daniel; Späth, Andreas

2013-01-01

Photodynamic inactivation of bacteria (PIB) by efficient singlet oxygen photosensitizers might be a beneficial alternative to antibiotics in the struggle against multiresistant bacteria. Phenothiazinium dyes belong to the most prominent classes of such sensitizers due to their intense absorption in the red-light region (λ abs, max ca. 600–680 nm, ε > 50000 L mol−1 cm−1), their low toxicity, and their attachment/penetration abilities. Except simple substituents like alkyl or hydroxyalkyl residues, nearly no modifications of the phenothiaziniums have been pursued at the auxochromic sites. By this, the properties of methylene blue derivatives and their fields of application are limited; it remains unclear if their potential antimicrobial efficacy may be enhanced, also to compete with porphyrins. We prepared a set of six mainly novel methylene blue derivatives with the ability of additional hydrogen bonding and/or additional cationic charges to study the substituents' effect on their activity/toxicity profiles and photophysical properties. Direct detection of singlet oxygen was performed at 1270 nm and the singlet oxygen quantum yields were determined. In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivate S. aureus and E. coli up to 7 log10 steps (99.99999%) without inherent toxicities in the nonirradiated state. PMID:23509728

Optimization of Trichomonas vaginalis Diagnosis during Pregnancy at a University Hospital, Argentina.

PubMed

Testardini, Pamela; Vaulet, María Lucía Gallo; Entrocassi, Andrea Carolina; Menghi, Claudia; Eliseht, Martha Cora; Gatta, Claudia; Losada, Mirta; Touzón, María Sol; Corominas, Ana; Vay, Carlos; Tatti, Silvio; Famiglietti, Angela; Fermepin, Marcelo Rodriguez; Perazzi, Beatriz

2016-04-01

The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) staining, and wet mount with sodium-acetate-formalin (SAF)/methylene blue method. PCR for 18S rRNA gene as well as culture in liquid medium were performed. The sensitivity and specificity of the microscopic examinations were evaluated considering the culture media positivity or the PCR techniques as gold standard. The frequency of T. vaginalis infection was 6.2% by culture and/or PCR, 5.2% by PCR, 4.7% by culture, 3.1% by SAF/methylene blue method and 2.8% by direct wet smear and prolonged MGG staining. The sensitivities were 83.3%, 75.0%, 50.0%, and 45.8% for PCR, culture, SAF/methylene blue method, and direct wet smear-prolonged MGG staining, respectively. The specificity was 100% for all the assessed methods. Microscopic examinations showed low sensitivity, mainly in asymptomatic pregnant patients. It is necessary to improve the detection of T. vaginalis using combined methods providing higher sensitivity, such as culture and PCR, mainly in asymptomatic pregnant patients, in order to prevent maternal and perinatal complications.

Comparison of Photocatalytic Performance of Different Types of Graphene in Fe3O4/SnO2 Composites

NASA Astrophysics Data System (ADS)

Paramarta, Valentinus; Taufik, Ardiansyah; Saleh, Rosari

2017-03-01

We have reported the role of annealing temperature Fe3O4/SnO2 nanocomposites as a photocatalyst for remove methylene blue (MB) dye from aqueous solution. However, how to enhanced the degradation performance of Fe3O4/SnO2 nanocomposites is important to its photocatalytic application. Therefore, in this work Fe3O4/SnO2 nanocomposites was combined with two different types of graphene materials (NGP and grahene) to improve the photocatalytic performance for remove methylene blue (MB) dye. Fe3O4/SnO2/NGP and Fe3O4/SnO2/graphene have been successfully synthesized by co-precipitation method. The influence of two types graphene on Fe3O4/SnO2 nanocomposites properties were systematically investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Thermal gravimetric analysis (TGA). Degradation of methylene Blue (MB) in aqueous solution was studied in detail under photocatalytic process. Effect of catalyst dosage (0.1-0.4 g/L) and scavengers on dye degradation were carried out to check the efficiency of photocatalyst. The results indicated Fe3O4/SnO2/graphene displayed higher photocatalytic activity than other catalyst. The reusability tests have also been done to ensure the stability of the used photocatalyst.

Determination of oestrous cycle of the rats by direct examination: how reliable?

PubMed

Yener, T; Turkkani Tunc, A; Aslan, H; Aytan, H; Cantug Caliskan, A

2007-02-01

For determination of the oestrous cycle in rats classical Papanicolaou technique has long been used successfully. Instead of using many stains in Papanicolaou, staining the vaginal secretions with only methylene blue has also been defined. Recently a new technique in which vaginal samples are directly examined under light microscope has been introduced. The aim of this study was to assess the reliability of this new technique by comparing it with the classical staining techniques. From 20 Wistar rats 60 vaginal samples were collected with a micropipette, three from each. Briefly, the vagina was flushed two to three times then the fluid was placed onto a glass slide. The fluid was equally distributed onto three glass slides. The glass slides were coded. Two samples were stained with Papanicolaou and methylene blue while the other one was examined directly. Determination of the phases of the oestrous cycle was made by the same histologist who was blinded to the groups and coding system. After determination of the oestrous phase in all samples, the results were compared and it was found that the results were matching. In conclusion, the same results can be obtained with the direct examination technique and this technique is reliable, so there is no need to use relatively time-consuming, less practical and more expensive techniques such as Papanicolaou or methylene blue.

Titanium dioxide-gold nanocomposite materials embedded in silicate sol-gel film catalyst for simultaneous photodegradation of hexavalent chromium and methylene blue.

PubMed

Pandikumar, Alagarsamy; Ramaraj, Ramasamy

2012-02-15

Aminosilicate sol-gel supported titanium dioxide-gold (EDAS/(TiO(2)-Au)(nps)) nanocomposite materials were synthesized by simple deposition-precipitation method and characterized. The photocatalytic oxidation and reduction activity of the EDAS/(TiO(2)-Au)(nps) film was evaluated using hexavalent chromium (Cr(VI)) and methylene blue (MB) dye under irradiation. The photocatalytic reduction of Cr(VI) to Cr(III) was studied in the presence of hole scavengers such as oxalic acid (OA) and methylene blue (MB). The photocatalytic degradation of MB was investigated in the presence and absence of Cr(VI). Presence of Au(nps) on the (TiO(2))(nps) surface and its dispersion in the silicate sol-gel film (EDAS/(TiO(2)-Au)(nps)) improved the photocatalytic reduction of Cr(VI) and oxidation of MB due to the effective interfacial electron transfer from the conduction band of the TiO(2) to Au(nps) by minimizing the charge recombination process when compared to the TiO(2) and (TiO(2)-Au)(nps) in the absence of EDAS. The EDAS/(TiO(2)-Au)(nps) nanocomposite materials provided beneficial role in the environmental remediation and purification process through synergistic photocatalytic activity by an advanced oxidation-reduction processes. Copyright © 2011 Elsevier B.V. All rights reserved.

Hydrothermal synthesis of graphene oxide/multiwalled carbon nanotube/Fe3O4 ternary nanocomposite for removal of Cu (II) and methylene blue

NASA Astrophysics Data System (ADS)

Long, Zhihang; Zhan, Yingqing; Li, Fei; Wan, Xinyi; He, Yi; Hou, Chunyan; Hu, Hai

2017-09-01

In this work, highly activated graphene oxide/multiwalled carbon nanotube/Fe3O4 ternary nanocomposite adsorbent was prepared from a simple hydrothermal route by using ferrous sulfate as precursor. For this purpose, the graphene oxide/multiwalled carbon nanotube architectures were formed through the π-π attractions between them, followed by attaching Fe3O4 nanoparticles onto their surface. The structure and composition of as-prepared ternary nanocomposite were characterized by XRD, FTIR, XPS, SEM, TEM, Raman, TGA, and BET. It was found that the resultant porous graphene oxide/multiwalled carbon nanotube/Fe3O4 ternary nanocomposite with large surface area could effectively prevent the π-π stacking interactions between graphene oxide nanosheets and greatly improve sorption sites on the surfaces. Thus, owing to the unique ternary nanocomposite architecture and synergistic effect among various components, as-prepared ternary nanocomposite exhibited high separation efficiency when they were used to remove the Cu (II) and methylene blue from aqueous solutions. Furthermore, the adsorption isotherms of ternary nanocomposite structures for Cu (II) and methylene blue removal fitted the Langmuir isotherm model. This work demonstrated that the graphene oxide/multiwalled carbon nanotube/Fe3O4 ternary nanocomposite was promising as an efficient adsorbent for heavy metal ions and organic dye removal from wastewater in low concentration.

Oxycodone

MedlinePlus

... this type of medication for at least one week. Oxycodone is in a class of medications called ... have stopped taking them within the past two weeks: isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), ...

Hydromorphone

MedlinePlus

... this type of medication for at least one week and should not be used to treat mild ... have stopped taking them within the past 2 weeks: isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), ...

Photooxidation of Methionine

ERIC Educational Resources Information Center

Lewis, Catherine; Scouten, William H.

1976-01-01

Describes an experiment in which the photooxidation of methionine using free methylene blue as the sensitizer is applied to the isolated amino acid or to the methionyl residues of a complex polypeptide. (MLH)

40 CFR 417.191 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... methylene blue active substances amenable to measurement by the method described in “Methods for Chemical Analysis of Water and Wastes,” 1971, Environmental Protection Agency, Analytical Quality Control Laboratory...

Sensitive flotation-spectrophotometric determination of gold, based on the gold(I)-iodide-methylene blue system.

PubMed

Marczenko, Z; Jankowski, K

1985-04-01

The gold(I)-iodide-Methylene Blue (MB) system is suitable for flotation separation and spectrophotometric determination of gold. Under the optimum conditions [(MB(+))(AuI(2)(-))].3[(MB(+))(I(3)(-))] is formed, and floated with cyclohexane. The product is dissolved in methanol and its absorbance measured. The molar absorptivity is 3.4 x 10(5)1.mole(-1).cm(-1) at 655 nm. The proposed method is more than three times as sensitive as the Rhodamine B method. Pt, Pd, Ag and Hg interfere seriously, and Ir, Rh, Bi and Cd to a smaller extent. Preliminary separation of gold by precipitation with tellurium as a collector is recommended. The method has been applied to determination of gold traces (about 1 x 10(-4)%) in a copper sample.

Benzocaine-induced methaemoglobinaemia: a case study.

PubMed

Bittmann, Stefan; Krüger, Carsten

Benzocaine is a widely used topical anaesthetic and has been reported to cause toxic methaemoglobinaemia in otherwise healthy individuals with no predisposing risk factors. This article reports on a rare case of benzocaine-induced methaemoglobinaemia following adenotonsillectomy in a 5-year-old girl. Topical benzocaine was applied orally for the relief of postoperative wound pain on the eighth postoperative day. Two hours after application, generalized cyanosis, mild dyspnoea and some degree of agitation developed. The methaemoglobin level was 38.5%. Treatment with methylene blue was initiated immediately. Symptoms completely disappeared 4 hours after initiation of methylene blue therapy. The further course was uneventful. Therefore, all health professionals should be aware that topical anaesthetics after surgery can induce methaemoglobinaemia in children, even after a prolonged interval, and especially when applied on wound surfaces.

A rare side effect of transesophageal echocardiography: methemoglobinemia from topical benzocaine anesthesia.

PubMed

Jaffery, Zehra; Ananthasubramaniam, Karthik

2008-03-01

Benzocaine induced methemoglobinemia is an uncommon, potentially fatal condition. A 44-year-old woman with a history of hepatitis C and intravenous drug use was referred for transesophageal echocardiography for bacteremia evaluation. During induction of topical anesthesia with benzocaine spray she became cyanotic. Pulse oximetry revealed marked desaturation (75%) but was discordant from arterial blood O(2) saturation (99%). Due to clinical suspicion, methemoglobin level was measured and noted to be 69%. The patient was treated with 2 mg/kg of methylene blue intravenously with resolution of her symptoms. Physicians using topical anesthesia in endoscopic suites should be aware of this rare, potentially life-threatening treatable condition. High clinical suspicion and availability of methylene blue in endoscopy suites will facilitate prompt diagnosis and treatment.

Hydrothermally synthesized flower like MoS2 microsphere: A highly efficient adsorbent for methylene blue dye removal

NASA Astrophysics Data System (ADS)

Panda, Jnanranjan; Tudu, Bharati

2018-05-01

Herein, a flower like MoS2 (M1) microsphere assembled by layered porous nanosheet was successfully prepared by facile hydrothermal synthesis procedure. The structural, chemical and morphological characterizations for the as synthesized sample (M1) were carried out by powder x-ray diffraction (PXRD), Fourier-transform infrared (FTIR) and Field Emission Scanning Electron microscope (FESEM) respectively and spectroscopic characterization was performed by UV-Vis absorption and photoluminescence emission spectroscopy. The photocatalytic activity of the product was evaluated through photocatalytic degradation of Methylene Blue under visible light irradiation. The results indicate that layered MoS2structures possess significant adsorption ability, which may be useful for further research and practical applications of the layered MoS2 adsorbent in wastewater treatment.

THE RELATION OF THE BACTERIOSTATIC ACTION OF CERTAIN DYES TO OXIDATION-REDUCTION PROCESSES

PubMed Central

Dubos, René

1929-01-01

Oxidized indophenols and methylene blue are bacteriostatic for Pneumococcus and hemolytic streptococci of human and bovine origin, while the indigoes, malachite green and litmus are not toxic. 2-Chloroindophenol, the most positive of the indicators of oxidation-reduction potentials used, is also the only one to have a bacteriostatic action on cheese strains of Streptococcus hæmolyticus. Methylene blue and the indophenols are no longer bacteriostatic when present in a reduced form in a medium capable of maintaining them in such a condition. A comparison of these results with the growth in plain broth of the organisms studied suggests that the "inhibiting" dyes "poise" the medium at an oxidation potential outside the range in which the inhibited organisms can grow. PMID:19869565

Simulation of methylene blue adsorption by salts-treated beech sawdust in batch and fixed-bed systems.

PubMed

Batzias, F A; Sidiras, D K

2007-10-01

Batch and column kinetics of methylene blue adsorption on calcium chloride, zinc chloride, magnesium chloride and sodium chloride treated beech sawdust were simulated, using untreated beech sawdust as control, in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. The adsorption capacity, estimated according to Freundlich's model, the Langmuir constant K(L) and the adsorption capacity coefficient values, determined using the Bohart and Adams' bed depth service model indicate that salts treatment enhanced the adsorption properties of the original material. Since sawdust is an industrial waste/byproduct and the salts used can be recovered as spent liquids from various chemical operations, this process of adsorbent upgrading/modification might be considered to take place within an 'Industrial Ecology' framework.

Preconcentration of Sn (II) using the methylene blue on the activated carbon and its determination by spectrophotometry method.

PubMed

Khodadoust, Saeid; Cham Kouri, Narges

2014-04-05

A simple and accurate spectrophotometric method for determination of trace amounts of Sn (II) ion in soil sample was developed by using the methylene blue (MB) in the presence of activated carbon (AC) as the adsorbent Solid Phase Extraction (SPE) of Sn (II) and then determined by UV-Vis. The Beer's law is obeyed over the concentration range of 1-80ngmL(-1) of Sn (II) with the detection limits of 0.34ngmL(-1). The influence of type and volume of eluent, concentration of MB, pH, and amount of AC on sensitivity of spectrophotometric method were optimized. The method has been successfully applied for Sn (II) ion determination in soil sample. Copyright © 2013 Elsevier B.V. All rights reserved.

Photodynamic characterization and optimization using multifunctional nanoparticles for brain cancer treatment

NASA Astrophysics Data System (ADS)

Herrmann, Kristen; Lee Koo, Yong-Eun; Orringer, Daniel A.; Sagher, Oren; Philbert, Martin; Kopelman, Raoul

2013-03-01

Photosensitizer-conjugated polyacrylamide nanoparticles were prepared for in vivo characterization of the minimally invasive and localized treatment of photodynamic therapy (PDT) on brain tumors. By incorporating a variety of nanoparticle matrixes, choosing methylene blue as a photosensitizer, and targeting the nanoparticle by the use of F3 peptide we have made nanoparticle-based PDT improvements to current PDT efficiency. Quantitative growth patterns were determined through visual observation of the tumorigenic response to various treatments by the use of an animal cranial window model. PDT treatments with methylene blue-polyacrylamide (MB-PAA) nanoparticles produced significant adjournment of tumor growth over control groups, clearly demonstrating the advantages of nanoparticle-based PDT agents for the eradication of local tumors, leading to the potential palliation of the advancing disease.

Blue dye for identification of sentinel nodes in breast cancer and malignant melanoma: a systematic review and meta-analysis.

PubMed

Peek, Mirjam Cl; Charalampoudis, Petros; Anninga, Bauke; Baker, Rose; Douek, Michael

2017-02-01

The combined technique (radioisotope and blue dye) is the gold standard for sentinel lymph node biopsy (SLNB) and there is wide variation in techniques and blue dyes used. We performed a systematic review and meta-analysis to assess the need for radioisotope and the optimal blue dye for SLNB. A total of 21 studies were included. The SLNB identification rates are high with all the commonly used blue dyes. Furthermore, methylene blue is superior to iso-sulfan blue and Patent Blue V with respect to false-negative rates. The combined technique remains the most accurate and effective technique for SLNB. In order to standardize the SLNB technique, comparative trials to determine the most effective blue dye and national guidelines are required.

A randomized, prospective cross-over trial comparing methylene blue-directed biopsy and conventional random biopsy for detecting intestinal metaplasia and dysplasia in Barrett's esophagus.

PubMed

Ragunath, K; Krasner, N; Raman, V S; Haqqani, M T; Cheung, W Y

2003-12-01

The value of methylene blue-directed biopsies (MBDB) in detecting specialized intestinal metaplasia and dysplasia in Barrett's esophagus remains unclear. The aim of this study was to compare the accuracy of MBDB with random biopsy in detecting intestinal metaplasia and dysplasia in patients with Barrett's esophagus. A prospective, randomized, cross-over trial was undertaken to compare MBDB with random biopsy in patients with Barrett's esophagus segments 3 cm or more in length without macroscopic evidence of dysplasia or cancer. Dysplasia was graded as: indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, or carcinoma, and was reported in a blinded fashion. Fifty-seven patients were recruited, 44 of whom were male. A total of 1,269 biopsies were taken (MBDB-651, random biopsie-618). Analysis of the results by per-biopsy protocol showed that the MBDB technique diagnosed significantly more specialized intestinal metaplasia (75 %) compared to the random biopsy technique (68 %; P = 0.032). The sensitivity and specificity rates of MBDB for diagnosing specialized intestinal metaplasia were 91 % (95 % CI, 88 - 93 %) and 43 % (95 % CI, 36 - 51 %), respectively. The sensitivity and specificity rates of MBDB for diagnosing dysplasia or carcinoma were 49 % (95 % CI, 38 - 61 %) and 85 % (95 % CI, 82 - 88 %), respectively. There were no significant differences in the diagnosis of dysplasia and carcinoma - MBDB 12 %, random biopsy 10 %. The methylene blue staining pattern appeared to have an influence on the detection of specialized intestinal metaplasia and dysplasia/carcinoma. Dark blue staining was associated with increased detection of specialized intestinal metaplasia (P < 0.0001), and heterogeneous staining (P = 0.137) or no staining (P = 0.005) were associated with dysplasia and/or carcinoma detection. The MBDB technique prolonged the endoscopy examination by an average of 6 min. The diagnostic accuracy of the MBDB technique was superior to that of the random biopsy technique for identifying specialized intestinal metaplasia, but not dysplasia or carcinoma. The intensity of methylene blue staining has an influence on the detection of specialized intestinal metaplasia and dysplasia or carcinoma, which may help in targeting the biopsies. Although MBDB prolongs the endoscopy procedure slightly, it is a safe and well-tolerated procedure. Further clinical studies on the MBDB technique exclusively in endoscopically normal dysplastic Barrett's esophagus are needed.

Unveiling One-Dimensional Supramolecular Structures Formed through π-π Stacking of Phenothiazines by Differential Pulse Voltammetry.

PubMed

Carvalho, Fernando R; Zampieri, Eduardo H; Caetano, Wilker; Silva, Rafael

2017-05-19

Organic-based nanomaterials can be self-assembled by strong and directional intermolecular forces such as π-π interactions. Experimental information about the stability, size, and geometry of the formed structures is very limited for species that easily aggregate, even at very low concentrations. Differential pulse voltammetry (DPV) can unveil the formation, growth, and also the stability window of ordered, one-dimensional, lamellar self-aggregates formed by supramolecular π stacking of phenothiazines at micromolar (10 -6  mol L -1 ) concentrations. The self-diffusion features of the species at different concentrations are determined by DPV and used to probe the π staking process through the concept of the frictional resistance. It is observed that toluidine blue and methylene blue start to self-aggregate around 9 μmol L -1 , and that the self-aggregation process occurs by one-dimensional growth as the concentration of the phenothiazines is increased up to around 170 μmol L -1 for toluidine blue and 200 μmol L -1 for methylene blue. At higher concentrations, the aggregation process leads to structures with lower anisometry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The photodynamic effect of methylene blue and toluidine blue on Candida albicans is dependent on medium conditions.

PubMed

Carvalho, Gabriela Guimarães; Felipe, Monalisa Poliana; Costa, Maricilia Silva

2009-10-01

Due to the increased number of immunocompromised patients, the infections associated with the pathogen of the genus Candida and other fungi have increased dramatically. Photodynamic antimicrobial chemotherapy (PACT) has been presented as a potential antimicrobial therapy, in a process that combines light and a photosensitizing drug, which promotes a phototoxic response by the treated cells. In this work, we studied the effects of the different medium conditions during PACT, using either methylene blue (MB) or toluidine blue (TB) on Candida albicans. The inhibition of the growth produced by PACT was decreased for different pH values (6.0, 7.0, and 8.0) in a buffered medium. The phototoxic effects were observed only in the presence of saline (not buffered medium). PACT was modulated by calcium in a different manner using either MB or TB. Also when using MB both verapamil or sodium azide were able to decrease the phototoxic effects on the C. albicans. These results show that PACT is presented as a new and promising antifungal therapy, however, new studies are necessary to understand the mechanism by which this event occurs.

In situ Fenton reagent generated from TiO2/Cu2O composite film: a new way to utilize TiO2 under visible light irradiation.

PubMed

Zhang, Yong-Gang; Ma, Li-Li; Li, Jia-Lin; Yu, Ying

2007-09-01

TiO2/Cu2O composite is prepared by a simple electrochemical method and coated on glass matrix through a spraying method. The obtained composite is characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of TiO2/Cu2O composite films with different ratio of TiO2 and Cu2O on photodegradation of the dye methylene blue under visible light is investigated in detail. It is found that the photocatalytic activity of TiO2/Cu2O composite film with the presence of FeSO4 and EDTA is much higher than that for the similar system with only TiO2 and Cu2O film respectively. Without the presence of FeSO4 and EDTA, there is no degradation for methylene blue. The exploration of the optimized parameters for the degradation of methylene blue by using TiO2/Cu2O composite film as catalyst under visible light was also carried out. The most significant factor is the amount of Ti02 in the composite, and the second significant factor is the concentration of FeSO4. During the degradation of methylene blue under visible light, TiO2/Cu2O composite film generates H202, and Fenton regent is formed with Fe2+ and EDTA, which is detected in this study. The mechanism for the great improvement of photocatalytic activity of TiO2/Cu2O composite film under visible light is proposed by the valence band theory. Electrons excitated from TiO2/Cu2O composite under visible light are transferred from the conduction band of Cu2O to that of Ti02. The formed intermediate state of Ti 3+ ion is observed by X-ray photoelectron spectroscopy (XPS) on the TiO/Cu2O composite film. Additionally, the accumulated electrons in the conduction band of TiO2 are transferred to oxygen on the TiO2 surface for the formation of O2- or O2(2-), which combines with H+ to form H2O2. The evolved H202 with FeSO4 and EDTA forms Fenton reagentto degrade methylene blue. Compared to the traditional Fenton reagent, this new kind of in situ Fenton reagent generated from TiO2/Cu2O composite film does not need to supply H202. It is expected to be easily recycled, which may reduce second pollution and the cost of wastewater treatment. Moreover, this TiO/Cu2O composite film with FeSO4 and EDTA provides a new way to take advantage of TiO2 under visible light.

HOST-PARASITE INTERACTIONS AND GENETICS OF ACTINOPHAGES

DTIC Science & Technology

A very brief summary is given of work involving the photoinactivation of actinophages by proflavin and methylene blue, and the synergistic toxicity of bacterial endotoxin and the antitumor antibiotic pactamycin.

Enhanced photocatalytic activity of Te-doped Bi{sub 2}MoO{sub 6} under visible light irradiation: Effective separation of photogenerated carriers resulted from inhomogeneous lattice distortion and improved electron capturing ability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Shuguang, E-mail: csustcsg@yahoo.com; Li, Yuhan; Wu, Zixu

Te-doped Bi{sub 2}MoO{sub 6} photocatalyst was hydrothermally synthesized, and nonmetal atoms Te were homogeneously incorporated into Bi{sub 2}MoO{sub 6} lattice with the substitution of Te{sup 4+} to Mo{sup 6+}. With increasing Te-doping concentration in Bi{sub 2}MoO{sub 6}, no detectable band-gap narrowing but more and more severe inhomogeneous lattice distortions were determined. The activity of Bi{sub 2}MoO{sub 6} photocatalyst was evaluated through methylene blue degradation under visible light irradiation (λ>410 nm) and was greatly enhanced by Te-doping. When Te-doped Bi{sub 2}MoO{sub 6} was synthesized at Te/Mo molar ratio of 7.5%, a maximum first-order rate constant of methylene blue degradation was obtained.more » The inhomogeneous lattice distortion generated an internal dipole moment, and the holes generated with the substitution of Te{sup 4+} to Mo{sup 6+} acted as the capturing centers of photogenerated electrons, thus the effective separation of photogenerated carriers was facilitated to result in a relatively high concentration of holes on the surface of Te-doped Bi{sub 2}MoO{sub 6} to be favorable for the efficient methylene blue degradation. - Graphical abstract: With the substitution of Te{sup 4+} to Mo{sup 6+}, effective separation of photogenerated carriers resulted from inhomogeneous lattice distortion and improved electron capturing ability is achieved to be responsible for enhanced photocatalytic activity of Te-doped Bi{sub 2}MoO{sub 6}. - Highlights: • Nonmetal Te is incorporated into Bi{sub 2}MoO{sub 6} with the substitution of Te{sup 4+} to Mo{sup 6+}. • Revealing inhomogeneous lattice distortion and improved electron capturing ability. • Effective separation of photogenerated carriers in Te-doped Bi{sub 2}MoO{sub 6} is achieved. • The mechanism of methylene blue degradation over Te-doped Bi{sub 2}MoO{sub 6} is proposed.« less

Methylene blue not ferrocene: Optimal reporters for electrochemical detection of protease activity.

PubMed

González-Fernández, Eva; Avlonitis, Nicolaos; Murray, Alan F; Mount, Andrew R; Bradley, Mark

2016-10-15

Electrochemical peptide-based biosensors are attracting significant attention for the detection and analysis of proteins. Here we report the optimisation and evaluation of an electrochemical biosensor for the detection of protease activity using self-assembled monolayers (SAMs) on gold surfaces, using trypsin as a model protease. The principle of detection was the specific proteolytic cleavage of redox-tagged peptides by trypsin, which causes the release of the redox reporter, resulting in a decrease of the peak current as measured by square wave voltammetry. A systematic enhancement of detection was achieved through optimisation of the properties of the redox-tagged peptide; this included for the first time a side-by-side study of the applicability of two of the most commonly applied redox reporters used for developing electrochemical biosensors, ferrocene and methylene blue, along with the effect of changing both the nature of the spacer and the composition of the SAM. Methylene blue-tagged peptides combined with a polyethylene-glycol (PEG) based spacer were shown to be the best platform for trypsin detection, leading to the highest fidelity signals (characterised by the highest sensitivity (signal gain) and a much more stable background than that registered when using ferrocene as a reporter). A ternary SAM (T-SAM) configuration, which included a PEG-based dithiol, minimised the non-specific adsorption of other proteins and was sensitive towards trypsin in the clinically relevant range, with a Limit of Detection (LoD) of 250pM. Kinetic analysis of the electrochemical response with time showed a good fit to a Michaelis-Menten surface cleavage model, enabling the extraction of values for kcat and KM. Fitting to this model enabled quantitative determination of the solution concentration of trypsin across the entire measurement range. Studies using an enzyme inhibitor and a range of real world possible interferents demonstrated a selective response to trypsin cleavage. This indicates that a PEG-based peptide, employing methylene blue as redox reporter, and deposited on an electrode as a ternary SAM configuration, is a suitable platform to develop clinically-relevant and quantitative electrochemical peptide-based protease biosensing. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

A novel bio-degradable polymer stabilized Ag/TiO2 nanocomposites and their catalytic activity on reduction of methylene blue under natural sun light.

PubMed

Geetha, D; Kavitha, S; Ramesh, P S

2015-11-01

In the present work we defined a novel method of TiO2 doped silver nanocomposite synthesis and stabilization using bio-degradable polymers viz., chitosan (Cts) and polyethylene glycol (PEG). These polymers are used as reducing agents. The instant formation of AgNPs was analyzed by visual observation and UV-visible spectrophotometer. TiO2 nanoparticles doped at different concentrations viz., 0.03, 0.06 and 0.09mM on PEG/Cts stabilized silver (0.04wt%) were successfully synthesized. This study presents a simple route for the in situ synthesis of both metal and polymer confined within the nanomaterial, producing ternary hybrid inorganic-organic nanomaterials. The results reveal that they have higher photocatalytic efficiencies under natural sun light. The synthesized TiO2 doped Ag nanocomposites (NCs) were characterized by SEM/EDS, TEM, XRD, FTIR and DLS with zeta potential. The stability of Ag/TiO2 nanocomposite is due to the high negative values of zeta potential and capping of constituents present in the biodegradable polymer which is evident from zeta potential and FT-IR studies. The XRD and EDS pattern of synthesized Ag/TiO2 NCs showed their crystalline structure, with face centered cubic geometry oriented in (111) plane. AFM and DLS studies revealed that the diameter of stable Ag/TiO2 NCs was approximately 35nm. Moreover the catalytic activity of synthesize Ag/TiO2 NCs in the reduction of methylene blue was studied by UV-visible spectrophotometer. The synthesized Ag/TiO2 NCs are observed to have a good catalytic activity on the reduction of methylene blue by bio-degradable which is confirmed by the decrease in absorbance maximum value of methylene blue with respect to time using UV-vis spectrophotometer. The significant enhancement in the photocatalytic activity of Ag/TiO2 nanocomposites under sun light irradiation can be ascribed to the effect of noble metal Ag by acting as electron traps in TiO2 band gap. Copyright © 2015. Published by Elsevier Inc.

Potential electron mediators to extract electron energies of RBC glycolysis for prolonged in vivo functional lifetime of hemoglobin vesicles.

PubMed

Kettisen, Karin; Bülow, Leif; Sakai, Hiromi

2015-04-15

Developing a functional blood substitute as an alternative to donated blood for clinical use is believed to relieve present and future blood shortages, and to reduce the risks of infection and blood type mismatching. Hemoglobin vesicle (HbV) encapsulates a purified and concentrated human-derived Hb solution in a phospholipid vesicle (liposome). The in vivo safety and efficacy of HbV as a transfusion alternative have been clarified. Auto-oxidation of ferrous Hb in HbV gradually increases the level of ferric methemoglobin (metHb) and impairs the oxygen transport capabilities. The extension of the functional half-life of HbV has recently been proposed using an electron mediator, methylene blue (MB), which acts as a shuttle between red blood cells (RBC) and HbV. MB transfers electron energies of NAD(P)H, produced by RBC glycolysis, to metHb in HbV. Work presented here focuses on screening of 15 potential electron mediators, with appropriate redox potential and water solubility, for electron transfer from RBC to HbV. The results are assessed with regard to the chemical properties of the candidates. The compounds examined in this study were dimethyl methylene blue (DMB), methylene green, azure A, azure B, azure C, toluidine blue (TDB), thionin acetate, phenazine methosulfate, brilliant cresyl blue, cresyl violet, gallocyanine, toluylene blue, indigo carmine, indigotetrasulfonate, and MB. Six candidates were found to be unsuitable because of their insufficient diffusion across membranes, or overly high or nonexistent reactivity with relevant biomolecules. However, 9 displayed favorable metHb reduction. Among the suitable candidates, phenothiazines DMB and TDB exhibited effectiveness like MB did. In comparison to MB, they showed faster reduction by electron-donating NAD(P)H, coupled with showing a lower rate of reoxidation in the presence of molecular oxygen. Ascertaining the best electron mediator can provide a pathway for extending the lifetime and efficiency of potential blood substitutes.

Acute Generalized Exanthematous Pustulosis Due to Oral Use of Blue Dyes

PubMed Central

Sener, Osman; Kose, Ösman; Safali, Mukerrem

2011-01-01

Acute generalized exanthematous pustulosis is a rare severe pustular cutaneous adverse reaction characterized by a rapid clinical course with typical histological findings. It is accompanied by fever and acute eruption of non-follicular pustules overlying erythrodermic skin. The causative agents are most frequently antibacterial drugs. We present a patient with acute generalized exanthematous pustulosis caused by methylene blue and indigotin dyes. PMID:22016599

Synthesis of gold nanochains via photoactivation technique and their catalytic applications.

PubMed

Sinha, Arun Kumar; Basu, Mrinmoyee; Sarkar, Sougata; Pradhan, Mukul; Pal, Tarasankar

2013-05-15

The article reports a simple photoactivation technique for the synthesis of chain like assembly of spherical Au nanocrystals using a nontoxic biochemical, β-cyclodextrin under ~365 nm UV-light irradiation. Under UV irradiation, β-cyclodextrin acts as a reducing as well as capping agent and eventually becomes a stabilizing linker for Au nanoparticles. The UV-visible spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopic techniques are employed to systematically characterize the Au nanochains. Additionally, it is shown that the Au nanocrystals act as an effective catalyst for the reduction in nitrobenzene to aniline and methylene blue to leuco methylene blue in presence of suitable reducing agent. The catalytic reduction reactions and kinetic parameters are evaluated from UV-visible spectroscopy. Copyright © 2013 Elsevier Inc. All rights reserved.

Reactive oxygen species generation in aqueous solutions containing GdVO4:Eu3+ nanoparticles and their complexes with methylene blue

NASA Astrophysics Data System (ADS)

Hubenko, Kateryna; Yefimova, Svetlana; Tkacheva, Tatyana; Maksimchuk, Pavel; Borovoy, Igor; Klochkov, Vladimir; Kavok, Nataliya; Opolonin, Oleksander; Malyukin, Yuri

2018-04-01

It this letter, we report the study of free radicals and reactive oxygen species (ROS) generation in water solutions containing gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) and their complexes with methylene blue (MB) photosensitizer. The catalytic activity was studied under UV-Vis and X-ray irradiation by three methods (conjugated dienes test, OH· radical, and singlet oxygen detection). It has been shown that the VNPs-MB complexes reveal high efficiency of ROS generation under UV-Vis irradiation associated with both high efficiency of OH· radicals generation by VNPs and singlet oxygen generation by MB due to nonradiative excitation energy transfer from VNPs to MB molecules. Contrary to that under X-ray irradiation, the strong OH . radicals scavenging by VNPs has been observed.

Reactive oxygen species generation in aqueous solutions containing GdVO4:Eu3+ nanoparticles and their complexes with methylene blue.

PubMed

Hubenko, Kateryna; Yefimova, Svetlana; Tkacheva, Tatyana; Maksimchuk, Pavel; Borovoy, Igor; Klochkov, Vladimir; Kavok, Nataliya; Opolonin, Oleksander; Malyukin, Yuri

2018-04-13

It this letter, we report the study of free radicals and reactive oxygen species (ROS) generation in water solutions containing gadolinium orthovanadate GdVO 4 :Eu 3+ nanoparticles (VNPs) and their complexes with methylene blue (MB) photosensitizer. The catalytic activity was studied under UV-Vis and X-ray irradiation by three methods (conjugated dienes test, OH· radical, and singlet oxygen detection). It has been shown that the VNPs-MB complexes reveal high efficiency of ROS generation under UV-Vis irradiation associated with both high efficiency of OH· radicals generation by VNPs and singlet oxygen generation by MB due to nonradiative excitation energy transfer from VNPs to MB molecules. Contrary to that under X-ray irradiation, the strong OH . radicals scavenging by VNPs has been observed.

Zirconium and silver co-doped TiO2 nanoparticles as visible light catalyst for reduction of 4-nitrophenol, degradation of methyl orange and methylene blue

NASA Astrophysics Data System (ADS)

Naraginti, Saraschandra; Stephen, Finian Bernard; Radhakrishnan, Adhithya; Sivakumar, A.

2015-01-01

Catalytic activity of Zr and Ag co-doped TiO2 nanoparticles on the reduction of 4-nitrophenol, degradation of methylene blue and methyl orange was studied using sodium borohydride as reducing agent. The nanoparticles were characterized using X-ray diffraction, energy dispersive X-ray, high resolution transmission electron microscopy, selected area electron diffraction and UV-Vis spectroscopy. The rate of the reduction/degradation was found to increase with increasing amount of the photocatalyst which could be attributed to higher dispersity and small size of the nanoparticles. The catalytic activity of Zr and Ag co-doped TiO2 nanoparticles showed no significant difference even after recycling the catalyst four times indicating a promising potential for industrial application of the prepared photocatalyst.

Nanostructure CdS/ZnO heterojunction configuration for photocatalytic degradation of Methylene blue

NASA Astrophysics Data System (ADS)

Velanganni, S.; Pravinraj, S.; Immanuel, P.; Thiruneelakandan, R.

2018-04-01

In the present manuscript, thin films of Zinc Oxide (ZnO) have been deposited on a FTO substrate using a simple successive ionic layer adsorption and reaction (SILAR) and chemical bath deposition (CBD) method. Cadmium Sulphide (CdS) nanoparticles are sensitized over ZnO thin films using SILAR method. The synthesized nanostructured CdS/ZnO heterojunction thin films was characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy and Raman spectroscopy techniques. The band gap of CdS nanoparticles over ZnO nanostructure was found to be about 3.20 eV. The photocatalytic activities of the deposited CdS/ZnO thin films were evaluated by the degradation of methylene blue (MB) in an aqueous solution under sun light irradiation.

Fabrication and characterization of nanowalls CdS/dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Abdulelah, Haider; Ali, Basil; Mahdi, M. A.; Hassan, J. J.; Al-Taay, H. F.; Jennings, P.

2017-06-01

A microwave assisted chemical bath deposition (MA-CBD) was adopted to fabricate nanowalls CdS nanocrystalline thin film. Nanomaterials (such as nanowalls structure) have attracted significant attention due to their fascinating properties and unique applications, especially in optoelectronic nanodevices. Here we describe the fabrication of dye sensitized solar cells (DSSCs) based nanowalls cadmium sulfide (CdS) nanocrystalline thin films. The surface morphology, crystalline structure, and optical properties of the prepared nanocrystalline thin films are investigated. Rhodamine B, Malachite green, Eosin methylene blue, and Cresyl violet perchlorate dyes are used to fabricate the DSSCS devices. Current-voltage (I-V) characteristics show that the nanowall CdS/Eosin methylene blue device is the highest conversion efficiency of 0.89% under 100 mW/cm2. However, heat treatment of the fabricated solar cells causes significant enhancement in the output of all devices.

Binding affinities of cationic dyes in the presence of activated charcoal and anionic surfactant in the premicellar region

NASA Astrophysics Data System (ADS)

Ali, Farman; Ibrahim, Muhammad; Khan, Fawad; Bibi, Iram; Shah, Syed W. H.

2018-03-01

Binding preferences of cationic dyes malachite green and methylene blue in a mixed charcoal-sodium dodecyl sulfate system have been investigated using UV-visible absorption spectroscopy. The dye adsorption shows surfactant-dependent patterns, indicating diverse modes of interactions. At low surfactant concentration, a direct binding to charcoal is preferred. Comparatively greater quantities of surfactant lead to attachment of dye-surfactant complex to charcoal through hydrophobic interactions. A simple model was employed for determination of equilibrium constant K eq and concentration of dye-surfactant ion pair N DS for both dyes. The values of binding parameters revealed that malachite green was directly adsorbed onto charcoal, whereas methylene blue was bound through surfactant monomers. The model is valid for low surfactant concentrations in the premicellar region. These findings have significance for material and environmental sciences.

Visible light driven photocatalytic degradation of methylene blue using novel camphor sulfonic acid doped polycarbazole/g-C3N4 nanocomposite

NASA Astrophysics Data System (ADS)

Praveena, P.; Dhanavel, S.; Sangamithirai, D.; Narayanan, V.; Stephen, A.

2018-04-01

A novel polycabazole(PCz)/graphitic carbon nitride(g-C3N4) nanocomposite was synthesized via chemical oxidative polymerization method. In the present work, camphor sulfonic acid (CSA) was used as a dopantand ammonium peroxydisulphate (APS) was used as an oxidizing agent. The PCz/g-C3N4 nanocompositewas characterizedusing X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and UV-Visible spectroscopy (UV-Vis). The obtained results confirm the successful formation of PCz/g-C3N4 nanocomposite. Visible light induced photocatalytic activity of the novel catalyst was demonstrated using methylene blue as a target pollutant. The results suggestthat PCz/g-C3N4 nanocomposite can be used as an effective catalyst for the degradation of organic pollutants from waste water.

Sensitizing of TiO2 with a merocyanine dye in the photocatalytic reduction of methylene blue

NASA Astrophysics Data System (ADS)

Kobasa, I. M.; Kondratyeva, I. V.; Kropelnytska, Yu. V.

Three merocyanine dyes (D) with various polymethine chain lengths were checked for their applicability as sensitizers for TiO2. Based on the absorption data and cyclic voltammetric redox potentials, the lower unoccupied molecular orbital (LUMO) energy was calculated. The LUMO energy was higher than the conductance band edge energy of the anatase-type TiO2 for all the dyes, meaning that they all can act as efficient sensitizers for various functional materials to be used in the wide-zone visible light solar cells, toxic wastes decontamination technologies and other similar applications. Merocyanines applicability as effective sensitizing agents was approved by construction of the heterostructures (HS) D/TiO2 consisting of the merocyanines and acting as photocatalysts in the test reaction of methylene blue (MB) reduction by formaldehyde.

In vivo and ex vivo sentinel node mapping does not identify the same lymph nodes in colon cancer.

PubMed

Andersen, Helene Schou; Bennedsen, Astrid Louise Bjørn; Burgdorf, Stefan Kobbelgaard; Eriksen, Jens Ravn; Eiholm, Susanne; Toxværd, Anders; Riis, Lene Buhl; Rosenberg, Jacob; Gögenur, Ismail

2017-07-01

Identification of lymph nodes and pathological analysis is crucial for the correct staging of colon cancer. Lymph nodes that drain directly from the tumor area are called "sentinel nodes" and are believed to be the first place for metastasis. The purpose of this study was to perform sentinel node mapping in vivo with indocyanine green and ex vivo with methylene blue in order to evaluate if the sentinel lymph nodes can be identified by both techniques. Patients with colon cancer UICC stage I-III were included from two institutions in Denmark from February 2015 to January 2016. In vivo sentinel node mapping with indocyanine green during laparoscopy and ex vivo sentinel node mapping with methylene blue were performed in all patients. Twenty-nine patients were included. The in vivo sentinel node mapping was successful in 19 cases, and ex vivo sentinel node mapping was successful in 13 cases. In seven cases, no sentinel nodes were identified. A total of 51 sentinel nodes were identified, only one of these where identified by both techniques (2.0%). In vivo sentinel node mapping identified 32 sentinel nodes, while 20 sentinel nodes were identified by ex vivo sentinel node mapping. Lymph node metastases were found in 10 patients, and only two had metastases in a sentinel node. Placing a deposit in relation to the tumor by indocyanine green in vivo or of methylene blue ex vivo could only identify sentinel lymph nodes in a small group of patients.

Use of a vessel sealant device for cystic duct ligation in the dog.

PubMed

Marvel, Sarah; Monnet, Eric

2014-11-01

To compare a vessel sealant device to hemostatic clips for cystic duct ligation in a canine cadaveric model. Experimental. Hepatobiliary systems were collected from normal dogs. A microtip pressure transducer was inserted into the common bile duct and a 20-24 g intravenous catheter was placed in a hepatic duct. The cystic duct was ligated with 1 of 3 techniques: vessel sealant device (VSD), 10 mm medium Endoclips™, or 10 mm large Endoclips™ with 6 specimens in each group. Methylene blue was infused until failure, which was recorded as seal/clip failure or retrograde movement of methylene blue into the liver. Mean failure pressure of the medium endoclip group was significantly lower than the large endoclip group (P = .014). There was no difference between the failure pressure of the VSD group and the medium and large endoclip groups (P = .097, P = .34, respectively). Failure by leakage at the cut surface of the cystic duct occurred in 2 specimens in the medium endoclip group while all others failed by retrograde flow of the methylene blue through the hepatic ducts. The vessel sealant device appears comparable to large endoclips for closure of the cystic duct in an acute cadaveric model, while medium endoclips may not fully compress or span the diameter of a cystic duct in large breed dogs and leak at lower pressures. © Copyright 2014 by The American College of Veterinary Surgeons.

Modified solvothermal synthesis of cobalt ferrite (CoFe2O4) magnetic nanoparticles photocatalysts for degradation of methylene blue with H2O2/visible light

NASA Astrophysics Data System (ADS)

Kalam, Abul; Al-Sehemi, Abdullah G.; Assiri, Mohammed; Du, Gaohui; Ahmad, Tokeer; Ahmad, Irfan; Pannipara, M.

2018-03-01

Different grads of magnetic nano-scaled cobalt ferrites (CoFe2O4) photocatalysts were synthesized by modified Solvothermal (MST) process with and without polysaccharide. The indigenously synthesized photocatalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TGA), Fourier transform infrared (FT-IR), UV-visible (UV-vis) spectroscopy and N2 adsorption-desorption isotherm method. The Fourier transform infrared spectroscopy study showed the Fe-O stretching vibration 590-619 cm-1, confirming the formation of metal oxide. The crystallite size of the synthesized photocatalysts was found in the range between 20.0 and 30.0 nm. The surface area of obtained magnetic nanoparticles is found to be reasonably high in the range of 63.0-76.0 m2/g. The results shown that only MST-2 is the most active catalyst for photo-Fenton like scheme for fast photodegradation action of methylene blue dye, this is possible due to optical band gap estimated of 2.65 eV. Captivatingly the percentage of degradation efficiency increases up to 80% after 140 min by using MST-2 photocatalyst. Photocatalytic degradation of methylene blue (MB) dye under visible light irradiation with cobalt ferrite magnetic nanoparticles followed first order kinetic constant and rate constant of MST-2 is almost 2.0 times greater than MST-1 photocatalyst.

Photocatalytic degradation of methylene blue dye by zinc oxide nanoparticles obtained from precipitation and sol-gel methods.

PubMed

Balcha, Abebe; Yadav, Om Prakash; Dey, Tania

2016-12-01

Zinc oxide (ZnO) nanoparticles were synthesized by precipitation and sol-gel methods. The aim of this study was to understand how different synthetic methods can affect the photocatalytic activity of ZnO nanoparticles. As-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD) and UV-Visible spectroscopic techniques. XRD patterns of ZnO powders synthesized by precipitation and sol-gel methods revealed their hexagonal wurtzite structure with crystallite sizes of 30 and 28 nm, respectively. Their photocatalytic activities were evaluated by photocatalytic degradation of methylene blue, a common water pollutant, under UV radiation. The effects of operational parameters such as photocatalyst load and initial concentration of the dye on photocatalytic degradation of methylene blue were investigated. While the degradation of dye decreased over the studied dye concentration range of 20 to 100 mg/L, an optimum photocatalyst load of 250 mg/L was needed to achieve dye degradation as high as 81 and 92.5 % for ZnO prepared by precipitation and sol-gel methods, respectively. Assuming pseudo first-order reaction kinetics, this corresponded to rate constants of 8.4 × 10 -3 and 12.4 × 10 -3  min -1 , respectively. Hence, sol-gel method is preferred over precipitation method in order to achieve higher photocatalytic activity of ZnO nanostructures. Photocatalytic activity is further augmented by better choice of capping ligand for colloidal stabilization, starch being more effective than polyethylene glycol (PEG).

Activated carbons from waste of oil-palm kernel shells, sawdust and tannery leather scraps and application to chromium(VI), phenol, and methylene blue dye adsorption.

PubMed

Montoya-Suarez, Sergio; Colpas-Castillo, Fredy; Meza-Fuentes, Edgardo; Rodríguez-Ruiz, Johana; Fernandez-Maestre, Roberto

2016-01-01

Phenol, chromium, and dyes are continuously dumped into water bodies; the adsorption of these contaminants on activated carbon is a low-cost alternative for water remediation. We synthesized activated carbons from industrial waste of palm oil seed husks (kernel shells), sawdust, and tannery leather scraps. These materials were heated for 24 h at 600, 700 or 800°C, activated at 900°C with CO2 and characterized by proximate analysis and measurement of specific surface area (Brunauer-Emmett-Teller (BET) and Langmuir), and microporosity (t-plot). Isotherms showed micropores and mesopores in activated carbons. Palm seed activated carbon showed the highest fixed carbon content (96%), and Langmuir specific surface areas up to 1,268 m2/g, higher than those from sawdust (581 m2/g) and leather scraps (400 m2/g). The carbons were applied to adsorption of Cr(VI), phenol, and methylene blue dye from aqueous solutions. Phenol adsorption on activated carbons was 78-82 mg/g; on palm seed activated carbons, Cr(VI) adsorption at pH 7 was 0.35-0.37 mg/g, and methylene blue adsorption was 40-110 mg/g, higher than those from sawdust and leather scraps. Activated carbons from palm seed are promising materials to remove contaminants from the environment and represent an alternative application for vegetal wastes instead of dumping into landfills.

Is routine postoperative gastrografin study needed after laparoscopic sleeve gastrectomy? Experience of 712 cases.

PubMed

Wahby, M; Salama, A F; Elezaby, A F; Belgrami, F; Abd Ellatif, M E; El-Kaffas, H F; Al-Katary, M

2013-11-01

The current standard of care is to perform a postoperative gastrografin study following laparoscopic sleeve gastrectomy (LSG) to detect leakage or obstruction. This study evaluated the usefulness of this routine procedure. A retrospective chart review was performed in December 2012. All patients had routine intraoperative methylene blue testing to check for possible leakage from the staple line, and any leaking points were oversewn. We also performed postoperative contrast study (gastrografin) routinely in the first 24-48 h for all patients. From June 2007 to December 2012, 712 cases underwent LSG during the study period. Patients included in this study were 556 women (78.1%) and 156 men (21.9%). The mean age was 35 years. The mean BMI was 48 kg/m2. The operative time was 107 ± 29 min, and there were no conversions to open surgery. Intraoperative methylene blue test detected leakage in 28 cases (3.93%). Postoperative contrast study (gastrografin) was negative for leakage in all cases. Computed tomography (CT) scan with oral contrast study detected leakage in 1.4% (ten cases); none of these cases were detected by regular contrast study. Our study showed that intraoperative methylene blue test for leakage is a very sensitive and effective method for detecting leakage during sleeve gastrectomy and should be done routinely in all cases. Routine postoperative contrast study is not needed to detect leakage unless clinically indicated in selected cases, and in such cases contrast-enhanced CT scans are the modality of choice.

Indocyanine green-enhanced fluorescence in laparoscopic sleeve gastrectomy.

PubMed

Frattini, Francesco; Lavazza, Matteo; Mangano, Alberto; Amico, Francesco; Rausei, Stefano; Rovera, Francesca; Boni, Luigi; Dionigi, Gianlorenzo

2015-05-01

The aim of this study is to present our preliminary experience with indocyanine green fluorescence (IGF) imaging in laparoscopic sleeve gastrectomy. After dissection of the greater curve sleeve, gastrectomy is performed using a linear articulated stapler. Once the stomach is resected, an indocyanine green solution is prepared and injected in a periferic vein. A laparoscopic system with a high-definition camera system connected to a laparoscope equipped with a specific filter for optimal detection of the near-infrared fluorescence was used at all times as previously reported in a paper of Boni et al. A methylene blue test is routinely performed after near-infrared fluorescence, and a routine gastrografin upper gastrointestinal study is performed on postoperative day 2. We retrospectively identified 15 patients undergoing laparoscopic sleeve gastrectomy between April and October 2014. IGF imaging was used for all patients. A regular and homogeneous perfusion was observed along the entire gastric sleeve including the esophago-gastric junction. On the contrary, the excised specimen appeared devascularized at IGF imaging as expected. Intraoperative methylene blue test was negative in all cases. The contrast swallow did not document any leak. Neither clinical leak nor other complications occurred postoperatively (minimum follow-up of 2 months). IGF is a recent development in minimally invasive surgery. In this preliminary experience, IGF results resemble to intraoperative methylene blue test and postoperative contrast swallow ones. IGF allows a real-time assessment and gives a direct image of tissue perfusion and vascularization. Moreover, IGF may be helpful to explain the exact pathogenesis of gastric leak.

Efficient degradation of Methylene Blue dye over highly reactive Cu doped strontium titanate (SrTiO3) nanoparticles photocatalyst under visible light.

PubMed

Rahman, Qazi Inamur; Ahmad, Musheer; Misra, Sunil Kumar; Lohani, Minaxi

2012-09-01

Visible light induced photocatalysts of Cu doped SrTiO3 (Cu/SrTiO3) nanoparticles with the size -60-75 nm were prepared via facile sol-gel method. The morphological, optical, crystalline properties and compositions of synthesized Cu/SrTiO3 nanoparticles were thoroughly characterized by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), ultra violet-visible spectroscopy (UV-Vis) and energy dispersive X-ray (EDX). A significant red shift in the UV-diffused reflectance spectrum was observed and the absorption edge shifted to visible region by the Cu doping. Surprisingly, the band gap of SrTiO3 was changed from 3.2 eV drop to 2.96 eV. The photocatalytic activity of the synthesized Cu/SrTiO3 nanoparticles was demonstrated for the degradation of Methylene Blue dye under visible light irradiation. The formation of new acceptor region in Cu/SrTiO3 was responsible for high photocatalytic activity of Cu/SrTiO3 nanoparticles. The results showed that the Methylene Blue dye was degraded by -66% within time span of 2 h over the Cu/SrTiO3 nanoparticles. This dye degradation reaction followed the Langmuir-Hinshelwood kinetics and also exhibited first order reaction rate. The calculated rate constant for the degradation reaction following first order kinetics was k = 0.0016 min(-1).

Aminothienopyridazines and Methylene Blue Affect Tau Fibrillization via Cysteine Oxidation*

PubMed Central

Crowe, Alex; James, Michael J.; Lee, Virginia M.-Y.; Smith, Amos B.; Trojanowski, John Q.; Ballatore, Carlo; Brunden, Kurt R.

2013-01-01

Alzheimer disease and several other neurodegenerative disorders are characterized by the accumulation of intraneuronal fibrils comprised of the protein Tau. Tau is normally a soluble protein that stabilizes microtubules, with splice isoforms that contain either three (3-R) or four (4-R) microtubule binding repeats. The formation of Tau fibrils is thought to result in neuronal damage, and inhibitors of Tau fibrillization may hold promise as therapeutic agents. The process of Tau fibrillization can be replicated in vitro, and a number of small molecules have been identified that inhibit Tau fibril formation. However, little is known about how these molecules affect Tau fibrillization. Here, we examined the mechanism by which the previously described aminothieno pyridazine (ATPZ) series of compounds inhibit Tau fibrillization. Active ATPZs were found to promote the oxidation of the two cysteine residues within 4-R Tau by a redox cycling mechanism, resulting in the formation of a disulfide-containing compact monomer that was refractory to fibrillization. Moreover, the ATPZs facilitated intermolecular disulfide formation between 3-R Tau monomers, leading to dimers that were capable of fibrillization. The ATPZs also caused cysteine oxidation in molecules unrelated to Tau. Interestingly, methylene blue, an inhibitor of Tau fibrillization under evaluation in Alzheimer disease clinical trials, caused a similar oxidation of cysteines in Tau and other molecules. These findings reveal that the ATPZs and methylene blue act by a mechanism that may affect their viability as potential therapeutic agents. PMID:23443659

Comparison on characteristic of Mesoparticle Graphene Sand Composite (MGSC) using different types of sugar to remove methylene blue

NASA Astrophysics Data System (ADS)

Zularisam, A. W.; Wahida, Norul; Alfian, Ahmad

2017-07-01

This paper presents the green method to synthesis two types of adsorbent called mesoparticle graphene sand composite (MGSC) by using table sugar (MGSCts) and arenga palm sugar (MGSCaps) as different carbon sources to remove methylene blue acted as a dye model. Immobilisations of these materials on sand were introduced by using pyrolysis method without binder usage. Sand was treated by removing deleterious materials before sieved. The solutions of sugar were prepared and heated to 95 °C. The sand and sugar solutions were mixed and constantly stirred before putting them in furnace with nitrogen environment to produce MGSCts and MGSCaps. The composites were activated by using concentrated sulphuric acid to open the pores and maximise the capacity of absorbency. The analyses on the characteristic of both MGSCts and MGSCaps were conducted through field emission scanning electron microscope (FESEM), elemental dispersive x-ray (EDX) and elemental mapping (EM). FESEM analyses exhibited that the coating process was done uniformly as there were layers of coating sheets formation on the sand particles surfaces. After conducting EDX and EM, there were major elements found in both MGSCts and MGSCaps which were carbon, oxygen and silica. EM exhibited the distribution of these elements were scattered on the MGSC’s surfaces. Removal of methylene blue was successfully carried out by using both MGSCts and MGSCaps, with maximum removal up to 40% at the first hour of contact time.

Tetramethylene glycol mediated hydrothermal synthesis of defect-rich SnO2 nanoparticles for fast adsorption and degradation of MB dye

NASA Astrophysics Data System (ADS)

Rani, Barkha; Jadhao, Charushila Vasant; Sahu, Niroj Kumar

2018-04-01

Defect-rich pristine tin oxide nanoparticles (SnO2 NPs) with high colloidal stability have been synthesized by tetramethylene glycol (TMG) mediated hydrothermal process and characterized by XRD, TEM, Zeta Potential, PL spectroscopy and porosity measurement techniques. XRD result suggests the formation of rutile phase of SnO2 with average crystallite size of 2.65 nm. TMG act as a structure directing agent assist in the formation of network like structure of SnO2 NPs as confirmed from TEM. Significant blue shifts in the UV absorption spectrum as that of the bulk and defect bands in the PL spectrum are observed. The nanomaterial possesses very high surface area of 263.102 m2/g and large pore volume. The above properties strongly influence the photocatalytic degradation of methylene blue dye. Very fast adsorption and 96% degradation (under UV irradiation) has been achieved when 10 ppm methylene blue solutions is catalysed by 20 mg SnO2 NPs which pave the way for potential environmental application.

Indocyanine green detects sentinel lymph nodes in early breast cancer.

PubMed

Liu, Jun; Huang, Linping; Wang, Ning; Chen, Ping

2017-04-01

Objective To explore the clinical value of indocyanine green (ICG) for the fluorescence-guided detection of sentinel lymph nodes (SLNs) during sentinel lymph node biopsy (SLNB) in patients with early breast cancer. Methods This retrospective study included female patients with breast cancer. Patients were administered methylene blue and ICG using standard techniques. All SLNs that were collected during surgery were submitted for pathological examination. SLNs were defined as those that were either fluorescent, blue, fluorescent and blue or palpably suspicious. Surgical complications, axillary recurrence, distant metastasis and overall survival rates were observed postoperatively. Results A total of 60 patients were enrolled in the study. The fluorescence detection rate of SLNs was 100% ( n = 177), with a mean of 2.95 SLNs per patient. The methylene blue staining rate was 88.3% ( n = 106), with a mean of 1.77 SLNs per patient. Pathological assessment of intraoperative frozen specimens revealed SLN metastases in 10 patients, who immediately underwent axillary lymph node dissection. No patient had axillary recurrence or distant metastases, with a survival rate of 100%. Patients who underwent SLNB showed good appearance in the axillary wound, with no limited shoulder joint abduction and upper limb oedema. Conclusion Fluorescence-guided SLNB has several advantages and is suitable for clinical application.

In vitro lethal photosensitization of S. mutans using methylene blue and toluidine blue O as photosensitizers.

PubMed

Araújo, Patrícia V; Teixeira, Karina I R; Lanza, Lincoln D; Cortes, Maria E; Poletto, Luiz T A

2009-01-01

The purpose of this in vitro study was to evaluate the antimicrobial effect of photodynamic therapy on Streptococcus mutans (A TCC 25175) suspensions, using a red laser for one minute in combination with toluidine blue O (TBO) or methylene blue (MB). Both photosensitizers were used in three concentrations (25, 10 and 5 mg/L). The activity ofphotosensitizers and laser irradiation were tested separately on the bacteria, as well as the irradiation of this light source in the presence of the TBO or MB. These groups were compared to a control group, in which the microorganism did not receive any treatment. The activity of both TBO and MB or laser irradiation, alone, were not able to reduce the number of S. mutans. In the groups of lethal photosensitization, a bacterial reduction of 70% for TBO and 73% for MB was observed when these photosensitizers were used at 25 mg/L and a reduction of 48% was observed for MB at 5mg/L. In other concentrations there were no significant differences in comparison to the control group. Both the TBO and the MB at 25 mg/L associated with a red laser had an excellent potential for use in PDT in lethal sensitization of S. mutans.

Experimental and theoretical study using DFT method for the competitive adsorption of two cationic dyes from wastewaters

NASA Astrophysics Data System (ADS)

Regti, Abdelmajid; Ayouchia, Hicham Ben El; Laamari, My Rachid; Stiriba, Salah Eddine; Anane, Hafid; Haddad, Mohammadine El

2016-12-01

The adsorption of cationic dyes, Basic Yellow (BY28) and Methylene Blue (MB) on a new activated carbon from medlar species were studied in both single and binary system. Some experimental parameters, namely, pH, amount of adsorbent and contact time are studied. Quantum chemical results indicate that the adsorption efficiency was directly related to the dye electrophilicity power. Some theorical parameters were calculated and proved that MB is more electrophilic than BY28, than greatest interaction with surface sites. Kinetic study showed that the adsorption follows the pseudo-second-order model and Freundlich was the best model to describe the phenomenon in the single and binary system. According to the local reactivity results using Parr functions, the sulphur and nitrogen atoms will be the main adsorption sites.

Genetics Home Reference: methemoglobinemia, beta-globin type

MedlinePlus

... American Society of Hematology Resource List from the University of Kansas Medical Center: ... Melarkode K, Prinzhausen H. Hemoglobin M variant and congenital methemoglobinemia: methylene blue will not be effective in the presence of hemoglobin M. Can J ...

Magnetic removal of dyes from aqueous solution using multi-walled carbon nanotubes filled with Fe2O3 particles.

PubMed

Qu, Song; Huang, Fei; Yu, Shaoning; Chen, Gang; Kong, Jilie

2008-12-30

The Fe2O3 nanoparticles have been introduced into the multi-walled carbon nanotubes (MWCNTs) via wet chemical method. The resulting products are characterized by TEM, EDX, XRD and VSM. The magnetic MWCNTs have been employed as adsorbent for the magnetic separation of dye contaminants from water. The adsorption test of dyes (Methylene Blue and Neutral Red) demonstrates that it only takes 60min to attain equilibrium and the adsorption capacities for Methylene Blue and Neutral Red in the concentration range studied are 42.3 and 77.5mg/g, respectively. The magnetic MWCNTs can be easily manipulated in magnetic field for desired separation, leading to the removal of dyes from polluted water. The integration of MWCNTs with Fe2O3 nanoparticles has great potential application to remove organic dyes from polluted water.

Methylene blue adsorption on a DMPA lipid langmuir monolayer.

PubMed

Giner Casares, Juan José; Camacho, Luis; Martín-Romero, Maria Teresa; López Cascales, José Javier

2010-07-12

Adsorption of methylene blue (MB) onto a dimyristoylphosphatidic acid (DMPA) Langmuir air/water monolayer is studied by molecular dynamics (MD) simulations, UV reflection spectroscopy and surface potential measurements. The free-energy profile associated with MB transfer from water to the lipid monolayer shows two minima of -66 and -60 kJ mol(-1) for its solid and gas phase, respectively, corresponding to a spontaneous thermodynamic process. From the position of the free-energy minima, it is possible to predict the precise location of MB in the interior of the DMPA monolayer. Thus, MB is accommodated in the phosphoryl or carbonyl region of the DMPA Langmuir air/water interface, depending on the isomorphic state (solid or gas phase, respectively). Reorientation of MB, measured from the bulk solution to the interior of the lipid monolayer, passes from a random orientation in bulk solution to an orientation parallel to the surface of the lipid monolayer when MB is absorbed.

Towards nonionizing photoacoustic cystography

NASA Astrophysics Data System (ADS)

Kim, Chulhong; Jeon, Mansik; Wang, Lihong V.

2012-02-01

Normally, urine flows down from kidneys to bladders. Vesicoureteral reflux (VUR) is the abnormal flow of urine from bladders back to kidneys. VUR commonly follows urinary tract infection and leads to renal infection. Fluoroscopic voiding cystourethrography and direct radionuclide voiding cystography have been clinical gold standards for VUR imaging, but these methods are ionizing. Here, we demonstrate the feasibility of a novel and nonionizing process for VUR mapping in vivo, called photoacoustic cystography (PAC). Using a photoacoustic (PA) imaging system, we have successfully imaged a rat bladder filled with clinically being used methylene blue dye. An image contrast of ~8 was achieved. Further, spectroscopic PAC confirmed the accumulation of methylene blue in the bladder. Using a laser pulse energy of less than 1 mJ/cm2, bladder was clearly visible in the PA image. Our results suggest that this technology would be a useful clinical tool, allowing clinicians to identify bladder noninvasively in vivo.

Synthesis of Ag-ZnO with multiple rods (multipods) morphology and its application in the simultaneous photo-catalytic degradation of methyl orange and methylene blue.

PubMed

Arab Chamjangali, M; Bagherian, G; Javid, A; Boroumand, S; Farzaneh, N

2015-11-05

In this study, the photo-decolorization of a mixture of methylene blue (MB) and methyl orange (MO) was investigated using Ag-ZnO multipods. The photo-catalyst used, ZnO multipods, was successfully synthesized. The surface of ZnO microstructure was modified by deposition of different amounts of Ag nanoparticles (Ag NPs) using the photo-reduction method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis and atomic absorption spectroscopy. The photo-catalytic efficiency of Ag-ZnO is mainly controlled by the amount of Ag NPs deposited on the ZnO surface. The results obtained suggest that Ag-ZnO containing 6.5% Ag NPs, has the highest photo-catalytic performance in the simultaneous photo-degradation of dyes at a shorter time. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison effects and dielectric properties of different dose methylene-blue-doped hydrogels.

PubMed

Yalçın, O; Coşkun, R; Okutan, M; Öztürk, M

2013-08-01

The dielectric properties of methylene blue (MB)-doped hydrogels were investigated by impedance spectroscopy. The real part (ε') and the imaginary part (ε") of the complex dielectric constant and the energy loss tangent/dissipation factor (tan δ) were measured in the frequency range of 10 Hz to 100 MHz at room temperature for pH 5.5 value. Frequency variations of the resistance, the reactance, and the impedance of the samples have also been investigated. The dielectric permittivity of the MB-doped hydrogels is sensitive to ionic conduction and electrode polarization in low frequency. Furthermore, the dielectric behavior in high-frequency parts was attributed to the Brownian motion of the hydrogen bonds. The ionic conduction for MB-doped samples was prevented for Cole-Cole plots, while the Cole-Cole plots for pure sample show equivalent electrical circuit. The alternative current (ac) conductivity increases with the increasing MB concentration and the frequency.

Study of multi-functionality of lanthanum ferrite (LaFeO{sub 3})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaikwad, Vishwajit M.; Uikey, Pankaj; Acharya, Smita A., E-mail: saha275@yahoo.com

2015-06-24

In the present work, multifunctional behaviors of LaFeO{sub 3} (LFO) are investigated by studying its dielectric and photocatalytic properties, respectively. LFO is synthesized by microwave-assisted co-precipitation route. Orthorhombic structure is confirmed by X-ray diffraction (XRD) and data is well fitted using Rietveld refinement by Full-Prof suite. Frequency and Temperature dependence dielectric behavior are systematically studied. The dielectric constant of LFO was found to be 2500 – 3000 with dissipation factor less than 5%. Photodegradation of toxic dye (Methylene Blue) using as-prepared LFO is also investigated. UV-visible absorption spectra are used to study the photodegradation behaviour. Photodegradation of methylene blue (MB)more » taken from textile industries by LFO are reported. The colossal value of dielectric constant of LFO exhibits high potential to use as room temperature capacitive component for device miniaturization in microelectronics as well as photodegradation ability shows good photocatalyst.« less

Green synthesis of ZnO nanoparticles via complex formation by using Curcuma longa extract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fatimah, Is, E-mail: isfatimah@uii.ac.id; Yudha, Septian P.; Mutiara, Nur Afisa Lintang

Synthesis of ZnO nanoparticles(NPs) were conducted via Zn(II) complex formation by using Curcuma longa extract as template. Curcuma longa extract has the ability to form zinc ions complex with curcumin as ligating agent. Study on synthesis was conducted by monitoring thermal degradation of the material. Successful formation of zinc oxide nanoparticles was confirmed by employing x-ray diffraction, surface area analysis and transmission electron microscopy(TEM) studies. From the XRD analysis it is denoted that ZnO in hexagonal wurtzite phase was formed and particle size was varied as varied temperature. The data are also confirmed by TEM analysis which shows the particlemore » sie at the range 20-80nm. The NPs exhibited excelent photocatalytic activity for methylene blue degradation and also significant antibacterial activity for Eschericia coli. The activity in methylene blue degradation was also confirmed from fast chemical oxygen demand (COD) reduction.« less

Non-metal doped TiO2 nanotube arrays for high efficiency photocatalytic decomposition of organic species in water

NASA Astrophysics Data System (ADS)

Szkoda, Mariusz; Siuzdak, Katarzyna; Lisowska-Oleksiak, Anna

2016-10-01

Titanium dioxide is a well-known photoactive semiconductor with a variety of possible applications. The procedure of pollutant degradation is mainly performed using TiO2 powder suspension. It can also be exploited an immobilized catalyst on a solid support. Morphology and chemical doping have a great influence on TiO2 activity under illumination. Here we compare photoactivity of titania nanotube arrays doped with non-metal atoms: nitrogen, iodine and boron applied for photodegradation of organic dye - methylene blue and terephtalic acid. The doped samples act as a much better photocatalyst in the degradation process of methylene blue and lead to the formation of much higher amount of hydroxyl radicals (•OH) than undoped TiO2 nanotube arrays. The use of a catalyst active under solar light illumination in the form of thin films on a stable substrate can be scaled up for an industrial application.

One-Pot Synthesis of Reduced Graphene Oxide/Anatase Titanium Dioxide Composites for Photocatalytic Degradation of Methylene Blue.

PubMed

Lee, Hyo In; Park, Soo-Jin

2018-09-01

In this work, highly ordered TiO2-reduced graphene oxide sheets (TGS) were successfully fabricated via a one-pot solvothermal method with different amounts of graphene oxide (0.01, 0.03, 0.05, and 0.07 g). This was achieved by reacting graphene oxide (GO) layers with titanium isopropoxide as the TiO2 precursor. The TGS exhibited superior efficiency compared to pristine TiO2 and the best results were recorded for the TGS-0.05 sample. The presence of the reduced graphene oxide (rGO) component was determined to be an important factor governing the separation of the photogenerated electron-hole pair via interfacial charge transfer. The significantly increased activity of the TGS under simulated solar light in the degradation of methylene blue (MB) indicates that these materials are promising photocatalysts for efficient water purification.

One-pot synthesis of MnO2-chitin hybrids for effective removal of methylene blue.

PubMed

Dassanayake, Rohan S; Rajakaruna, Erandathi; Moussa, Hanna; Abidi, Noureddine

2016-12-01

Manganese dioxide (MnO 2 )-chitin-hybrid material was prepared by a facile "one-pot" synthesis method. MnO 2 -chitin hybrid was used for the effective removal of methylene blue (MB) from liquid solution as model for wastewater treatment. The hybrid obtained was characterized by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. The effect of pH and temperature were studied. MnO 2 -chitin hybrid showed high performance for oxidative decolorization and removal of MB. Typically, 25mL of MB (20mg/L) can be completely decolorized in 2.5min with 8.5mg of the MnO 2 -chitin hybrid. The hybrid material exhibited excellent recyclability and durability with the degradation value of 99% for MB after ten consecutive cycles. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultrasound-guided percutaneous injection of methylene blue to identify nerve pathology and guide surgery.

PubMed

Osorio, Joseph A; Breshears, Jonathan D; Arnaout, Omar; Simon, Neil G; Hastings-Robinson, Ashley M; Aleshi, Pedram; Kliot, Michel

2015-09-01

OBJECT The objective of this study was to provide a technique that could be used in the preoperative period to facilitate the surgical exploration of peripheral nerve pathology. METHODS The authors describe a technique in which 1) ultrasonography is used in the immediate preoperative period to identify target peripheral nerves, 2) an ultrasound-guided needle electrode is used to stimulate peripheral nerves to confirm their position, and then 3) a methylene blue (MB) injection is performed to mark the peripheral nerve pathology to facilitate surgical exploration. RESULTS A cohort of 13 patients with varying indications for peripheral nerve surgery is presented in which ultrasound guidance, stimulation, and MB were used to localize and create a road map for surgeries. CONCLUSIONS Preoperative ultrasound-guided MB administration is a promising technique that peripheral nerve surgeons could use to plan and execute surgery.

Evaluation of methylene blue, pyrimethamine and its combination on an in vitro Neospora caninum model.

PubMed

Pereira, Luiz Miguel; Vigato-Ferreira, Isabel Cristina; DE Luca, Gabriela; Bronzon DA Costa, Cássia Mariana; Yatsuda, Ana Patrícia

2017-05-01

Neospora caninum is an apicomplexan parasite strongly related to reproductive problems in cattle. The neosporosis control is not well established and several fronts are under development, predominantly based on immune protection, immunomodulation and chemotherapy. The use of anti-malarial drugs as therapeutic sources has, in theory, considerable potential for any apicomplexan. Drugs such as methylene blue (MB) and pyrimethamine (Pyr) represent therapeutic options for malaria; thus, their use for neosporosis should be assessed. In this work, we tested the effects of MB and Pyr on N. caninum proliferation and clearance, using LacZ-tagged tachyzoites. The drugs inhibited at nanomolar dosages and its combination demonstrated an antagonistic interaction in proliferation assays, according to the Chou and Talalay method for drug combination index. However, the drug combination significantly improved the parasite in vitro clearance. The repositioning of well-established drugs opens a short-term strategy to obtain low-cost therapeutics approaches against neosporosis.

Synergic in vitro combinations of artemisinin, pyrimethamine and methylene blue against Neospora caninum.

PubMed

Pereira, Luiz Miguel; de Luca, Gabriela; Abichabki, Nathália de Lima Martins; Bronzon da Costa, Cássia Mariana; Yatsuda, Ana Patrícia

2018-01-15

Neospora caninum is a member of Apicomplexa phylum, the causative agent of neosporosis. The neosporosis combat is not well established and several strategies related to vaccine, chemotherapy and immune modulation are under development. In this work, we evaluated the effects of artemisinin (Art), methylene blue (MB) and pyrimethamine (Pyr) alone or associated, on N. caninum proliferation and elimination using LacZ tagged tachyzoites. The reactive oxygen species (ROS) production after incubation with Art were also performed. Our results indicate that combinations of classical antimalarial drugs improve the parasite control, allowing the use of three drugs in a single dose. Additionally, artemisinin demonstrated distinct ROS production patterns in intra and extracellular N. caninum forms. The drug repurposing appears as a suitable approach, allowing a fast and safe method to evaluate old drugs but novel candidates against neosporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Plasma Discharge with Different Electrode Diameters for Reducing Methylene Blue Concentration

NASA Astrophysics Data System (ADS)

Rasyidah, H.; Kusumandari; Saraswati, T. E.; Anwar, M.

2018-03-01

Recently, plasma technology has gained attention since it overcomes the shortcomings of water treatment. This research studies the effect of electrode diameter of plasma discharge reactors on the concentration reduction of methylene blue as an organic solution. The plasma discharge reactor was built from a pair of stainless needle electrodes connected with high-AC voltage. The electrodes were placed approximately 2 mm above the solution and stirred at 5.5 rpm. The diameters of the electrodes were 2, 3.2 and 4 mm. The times for plasma treatment were set at 2, 4, 6, 8 and 10 min. Absorbance, temperature and pH of the solution were measured to know the effects of electrode diameter of the plasma reactor. Absorbance and pH significantly decreased after plasma treatment. The best of the absorbance reduction were obtained when the sample was treated under plasma discharge using the smallest diameter electrodes for 8-10 min.

Methylene Blue Protects Astrocytes against Glucose Oxygen Deprivation by Improving Cellular Respiration

PubMed Central

Roy Choudhury, Gourav; Winters, Ali; Rich, Ryan M.; Ryou, Myoung-Gwi; Gryczynski, Zygmunt; Yuan, Fang; Yang, Shao-Hua; Liu, Ran

2015-01-01

Astrocytes outnumber neurons and serve many metabolic and trophic functions in the mammalian brain. Preserving astrocytes is critical for normal brain function as well as for protecting the brain against various insults. Our previous studies have indicated that methylene blue (MB) functions as an alternative electron carrier and enhances brain metabolism. In addition, MB has been shown to be protective against neurodegeneration and brain injury. In the current study, we investigated the protective role of MB in astrocytes. Cell viability assays showed that MB treatment significantly protected primary astrocytes from oxygen-glucose deprivation (OGD) & reoxygenation induced cell death. We also studied the effect of MB on cellular oxygen and glucose metabolism in primary astrocytes following OGD-reoxygenation injury. MB treatment significantly increased cellular oxygen consumption, glucose uptake and ATP production in primary astrocytes. In conclusion our study demonstrated that MB protects astrocytes against OGD-reoxygenation injury by improving astrocyte cellular respiration. PMID:25848957

A Silver Nanoparticle-Modified Evanescent Field Optical Fiber Sensor for Methylene Blue Detection

PubMed Central

Luo, Ji; Yao, Jun; Lu, Yonggang; Ma, Wenying; Zhuang, Xuye

2013-01-01

A silver nanoparticle-modified evanescent field optical fiber sensor based on a MEMS microchannel chip has been successfully fabricated. Experimental results show that the sensor response decreases linearly with increasing concentration of analyte. Over a range of methylene blue concentrations from 0 to 0.4 μmol/mL, the sensor response is linear (R = 0.9496). A concentration variation of 0.1 μmol/mL can cause an absorbance change of 0.402 dB. Moreover, the optical responses of the same sensing fiber without decoration and modified with silver nanoparticles have also been compared. It can be observed that the output intensity of the Ag nanoparticle-modified sensor is enhanced and the sensitivity is higher. Meanwhile, the absorbance spectra are found to be more sensitive to concentration changes compared to the spectra of the peak wavelength. PMID:23519353

Nanoscale zero-valent iron incorporated with nanomagnetic diatomite for catalytic degradation of methylene blue in heterogeneous Fenton system.

PubMed

Zha, Yiming; Zhou, Ziqing; He, Haibo; Wang, Tianlin; Luo, Liqiang

2016-01-01

Nanoscale zero-valent iron (nZVI) incorporated with nanomagnetic diatomite (DE) composite material was prepared for catalytic degradation of methylene blue (MB) in heterogeneous Fenton system. The material was constructed by two facile steps: Fe3O4 magnetic nanoparticles were supported on DE by chemical co-precipitation method, after which nZVI was incorporated into magnetic DE by liquid-phase chemical reduction strategy. The as-prepared catalyst was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, magnetic properties measurement and nitrogen adsorption-desorption isotherm measurement. The novel nZVI@Fe3O4-diatomite nanocomposites showed a distinct catalytic activity and a desirable effect for degradation of MB. MB could be completely decolorized within 8 min and the removal efficiency of total organic carbon could reach to 90% after reaction for 1 h.

Magnetic diatomite(Kieselguhr)/Fe2O3/TiO2 composite as an efficient photo-Fenton system for dye degradation

NASA Astrophysics Data System (ADS)

Barbosa, Isaltino A.; Zanatta, Lucas D.; Espimpolo, Daniela M.; da Silva, Douglas L.; Nascimento, Leandro F.; Zanardi, Fabrício B.; de Sousa Filho, Paulo C.; Serra, Osvaldo A.; Iamamoto, Yassuko

2017-10-01

We explored the potential use of diatomite/Fe2O3/TiO2 composites as catalysts for heterogeneous photo-Fenton degradation of methylene blue under neutral pH. Such system consists in magnetic solids synthesized by co-precipitation with Fe2+/Fe3+ in the presence of diatomite, followed by impregnation of TiO2. The results showed that the optimal amount of the catalyst was 2.0 g L-1, since aggregation phenomena become significant above this concentration, which decreases the photodegradation activity. The catalyst is highly efficient in the degradation of methylene blue and shows an easy recovery by an external magnetic field. This allows for an effective catalyst reuse without significant loss of activity in catalytic cycles, which is a highly interesting prospect for recyclable dye degradation systems.

Synthesis of mesoporous poly(melamine-formaldehyde) particles by inverse emulsion polymerization.

PubMed

Schwarz, Dana; Weber, Jens

2017-07-15

Mesoporous poly(melamine-formaldehyde) (MF) particles with surface areas of up to 200m 2 g -1 were synthesized by an inverse emulsion polymerization using dodecane and Span80® as continuous phase. The finer details of the shape control (using emulsion techniques) and the porosity control (using silica nanoparticles as hard-template) are discussed. The impact of phase-separation processes on the observable porosity of the 20-200µm sized spherical particles is analysed by gas sorption methods and electron microscopy. The high density of amine and triazine functional groups in the porous MF particles make the material a promising adsorber for heavy metal ions and methylene blue. In a preliminary column experiment, the synthesized material exhibited a total capacity of 2.54mmol/g (≙ 812.4mg/g) for the adsorption of methylene blue. Copyright © 2017 Elsevier Inc. All rights reserved.

Preparation of iron oxide-impregnated spherical granular activated carbon-carbon composite and its photocatalytic removal of methylene blue in the presence of oxalic acid.

PubMed

Kadirova, Zukhra C; Hojamberdiev, Mirabbos; Katsumata, Ken-Ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Sharipov, Khasan; Okada, Kiyoshi

2014-01-01

The spherical granular activated carbon-carbon composites (GAC-Fe) with different iron oxide contents (Fe mass% = 0.6-10) were prepared by a pore volume impregnation method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2-adsorption results confirm the presence of amorphous iron oxide, pyrolytic carbon, and graphitized globular carbon nanoparticles covered with amorphous carbon in the CAG-Fe. The rate of photodegradation of methylene blue (MB) in aqueous solution under UV light in the presence of oxalic acid correlates with porosity of the prepared materials. The total MB removal includes the combination of adsorption and photodegradation without the addition of H2O2. The results of total organic carbon (TOC) analysis reveal that the decolorization of MB in aqueous solution containing oxalic acid corresponds to the decomposition of organic compounds to CO2 and H2O.

Study on the inclusion interaction of p-sulfonated calix[ n]arenes with Vitamin K 3 using methylene blue as a spectral probe

NASA Astrophysics Data System (ADS)

Lu, Qin; Gu, Jiashan; Yu, Huapeng; Liu, Chun; Wang, Lun; Zhou, Yunyou

2007-09-01

The characteristics of host-guest complexation between p-sulfonated calix[ n]arene ( SCnA, n = 4, 6) and Vitamin K 3 ( VK3) were investigated by fluorescence spectrometry and absorption spectrometry using methylene blue ( MB) as a probe. Interaction with MB and SCnA led to an obvious decrease in fluorescence intensity of MB, accompanying with shifts of emission peaks. Absorption peaks also showed interesting changes; however, when VK3 was added, fluorescence intensity and absorbance recovered and a slight and slow red shift was observed. The obtained results showed that the inclusion ability of p-sulphonated calix[ n]arenes towards VK3 was the order: p-sulphonated calix[6]arene ( SC6A) > p-sulphonated calix[4]arene ( SC4A). Relative mechanism was proposed to explain the inclusion process.

Study on the inclusion interaction of p-sulfonated calix[n]arenes with Vitamin K3 using methylene blue as a spectral probe.

PubMed

Lu, Qin; Gu, Jiashan; Yu, Huapeng; Liu, Chun; Wang, Lun; Zhou, Yunyou

2007-09-01

The characteristics of host-guest complexation between p-sulfonated calix[n]arene (SCnA, n = 4, 6) and Vitamin K(3) (VK(3)) were investigated by fluorescence spectrometry and absorption spectrometry using methylene blue (MB) as a probe. Interaction with MB and SCnA led to an obvious decrease in fluorescence intensity of MB, accompanying with shifts of emission peaks. Absorption peaks also showed interesting changes; however, when VK(3) was added, fluorescence intensity and absorbance recovered and a slight and slow red shift was observed. The obtained results showed that the inclusion ability of p-sulphonated calix[n]arenes towards VK(3) was the order: p-sulphonated calix[6]arene (SC6A) >p-sulphonated calix[4]arene (SC4A). Relative mechanism was proposed to explain the inclusion process.

Application of Synthetic Layered Sodium Silicate Magadiite Nanosheets for Environmental Remediation of Methylene Blue Dye in Water

PubMed Central

2017-01-01

The removal of methylene blue (MB) dye from water was investigated using synthetic nano-clay magadiite (SNCM). SNCM was synthesized by a hydrothermal treatment under autogenous pressure. A rosette-shaped single mesoporous magadiite phase with 16.63 nm average crystallite size and 33 m2∙g−1 Braunauer-Emmet-Teller (BET)-surface area was recorded. The adsorption results indicated the pronounced affinity of the SNCM to the MB dye molecules, which reached an adsorption uptake of 20.0 mg MB dye/g of SNCM. The elimination of MB dye by the SNCM was kinetically and thermodynamically considered; a pseudo-second-order kinetic model was attained, and its spontaneous, chemical, and endothermic nature was verified. SNCM was shown to be robust without a detectable reduction in the adsorption capacity after up to four times re-use. PMID:28773120

P25-graphene hydrogels: room-temperature synthesis and application for removal of methylene blue from aqueous solution.

PubMed

Hou, Chengyi; Zhang, Qinghong; Li, Yaogang; Wang, Hongzhi

2012-02-29

Herein we report a room-temperature synthesis of chemically bonded TiO2 (P25)-graphene composite hydrogels and their use as high performance visible light photocatalysts. The three-dimensional (3D) TiO2-carbon composite exhibits a significant enhancement in the reaction rate in the decontamination of methylene blue, compared to the bare P25. The 3D P25-graphene hydrogel is much easier to prepare and apply as a macroscopic device, compared to the 2D P25-graphene sheets. This work could provide new insights into the room-temperature synthesis of graphene-based materials. As a kind of the novel 3D graphene-based composite, the obtained high performance P25-graphene gel could be widely used in the environmental protection issues. Copyright © 2012. Published by Elsevier B.V.

Multiple exciton dissociation in CdSe quantum dots by ultrafast electron transfer to adsorbed methylene blue.

PubMed

Huang, Jier; Huang, Zhuangqun; Yang, Ye; Zhu, Haiming; Lian, Tianquan

2010-04-07

Multiexciton generation in quantum dots (QDs) may provide a new approach for improving the solar-to-electric power conversion efficiency in QD-based solar cells. However, it remains unclear how to extract these excitons before the ultrafast exciton-exciton annihilation process. In this study we investigate multiexciton dissociation dynamics in CdSe QDs adsorbed with methylene blue (MB(+)) molecules by transient absorption spectroscopy. We show that excitons in QDs dissociate by ultrafast electron transfer to MB(+) with an average time constant of approximately 2 ps. The charge separated state is long-lived (>1 ns), and the charge recombination rate increases with the number of dissociated excitons. Up to three MB(+) molecules per QD can be reduced by exciton dissociation. Our result demonstrates that ultrafast interfacial charge separation can effectively compete with exciton-exciton annihilation, providing a viable approach for utilizing short-lived multiple excitons in QDs.

Adsorption characteristics of methylene blue onto agricultural wastes lotus leaf in bath and column modes.

PubMed

Han, Xiuli; Wang, Wei; Ma, Xiaojian

2011-01-01

The adsorption potential of lotus leaf to remove methylene blue (MB) from aqueous solution was investigated in batch and fixed-bed column experiments. Langmuir, Freundlich, Temkin and Koble-Corrigan isotherm models were employed to discuss the adsorption behavior. The results of analysis indicated that the equilibrium data were perfectly represented by Temkin isotherm and the Langmuir saturation adsorption capacity of lotus leaf was found to be 239.6 mg g(-1) at 303 K. In fixed-bed column experiments, the effects of flow rate, influent concentration and bed height on the breakthrough characteristics of adsorption were discussed. The Thomas and the bed-depth/service time (BDST) models were applied to the column experimental data to determine the characteristic parameters of the column adsorption. The two models were found to be suitable to describe the dynamic behavior of MB adsorbed onto the lotus leaf powder column.

Oxygen detection using evanescent fields

DOEpatents

Duan, Yixiang [Los Alamos, NM; Cao, Weenqing [Los Alamos, NM

2007-08-28

An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

Removal of Methylene Blue and Orange-G from Waste Water Using Magnetic Biochar

NASA Astrophysics Data System (ADS)

Mubarak, N. M.; Fo, Y. T.; Al-Salim, Hikmat Said; Sahu, J. N.; Abdullah, E. C.; Nizamuddin, S.; Jayakumar, N. S.; Ganesan, P.

2015-04-01

The study on the removal of methylene blue (MB) and orange-G dyes using magnetic biochar derived from the empty fruit bunch (EFB) was carried out. Process parameters such as pH, adsorbent dosage, agitation speed and contact time were optimized using Design-Expert Software v.6.0.8. The statistical analysis reveals that the optimum conditions for the maximum adsorption of MB are at pH 2 and pH 10, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. While for orange-G, at pH 2, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. The maximum adsorption capacity of 31.25 mg/g and 32.36 mg/g for MB and orange-G respectively. The adsorption kinetic for both dyes obeyed pseudo-second order.

Green synthesis of ZnO nanoparticles via complex formation by using Curcuma longa extract

NASA Astrophysics Data System (ADS)

Fatimah, Is; Yudha, Septian P.; Mutiara, Nur Afisa Lintang

2016-02-01

Synthesis of ZnO nanoparticles(NPs) were conducted via Zn(II) complex formation by using Curcuma longa extract as template. Curcuma longa extract has the ability to form zinc ions complex with curcumin as ligating agent. Study on synthesis was conducted by monitoring thermal degradation of the material. Successful formation of zinc oxide nanoparticles was confirmed by employing x-ray diffraction, surface area analysis and transmission electron microscopy(TEM) studies. From the XRD analysis it is denoted that ZnO in hexagonal wurtzite phase was formed and particle size was varied as varied temperature. The data are also confirmed by TEM analysis which shows the particle sie at the range 20-80nm. The NPs exhibited excelent photocatalytic activity for methylene blue degradation and also significant antibacterial activity for Eschericia coli. The activity in methylene blue degradation was also confirmed from fast chemical oxygen demand (COD) reduction.

Molecular mechanism of tau aggregation induced by anionic and cationic dyes.

PubMed

Lira-De León, Karla I; García-Gutiérrez, Ponciano; Serratos, Iris N; Palomera-Cárdenas, Marianela; Figueroa-Corona, María Del P; Campos-Peña, Victoria; Meraz-Ríos, Marco A

2013-01-01

Abnormal tau filaments are a hallmark of Alzheimer's disease. Anionic dyes such as Congo Red, Thiazine Red, and Thioflavin S are able to induce tau fibrillization in vitro. SH-SY5Y cells were incubated with each dye for seven days leading to intracellular aggregates of tau protein, with different morphological characteristics. Interestingly, these tau aggregates were not observed when the Methylene Blue dye was added to the cell culture. In order to investigate the molecular mechanisms underlying this phenomenon, we developed a computational model for the interaction of the tau paired helical filament (PHF) core with every dye by docking analysis. The polar/electrostatic and nonpolar contribution to the free binding energy in the tau PHF core-anionic dye interaction was determined. We found that the tau PHF core can generate a positive net charge within the binding site localized at residuesLys311 and Lys340 (numbering according to the longest isoform hTau40). These residues are important for the binding affinity of the negative charges present in the anionic dyes causing an electrostatic environment that stabilizes the complex. Tau PHF core protofibril-Congo Red interaction has a stronger binding affinity compared to Thiazine Red or Thioflavin S. By contrast, the cationic dye Methylene Blue does not bind to nor stabilize the tau PHF core protofibrils. These results characterize the driving forces responsible for the binding of tau to anionic dyes leading to their self-aggregation and suggest that Methylene Blue may act as a destabilizing agent of tau aggregates.

Sodium Hydroxide Activated Nanoporous Carbons Based on Lapsi Seed Stone.

PubMed

Joshi, Sahira; Shrestha, Lok Kumar; Kamachi, Yuichiro; Yamauchi, Yusuke; Pradhananga, Mandira Adhikari; Pokhrel, Bhadra Prasad; Ariga, Katsuhiko; Pradhananga, Raja Ram

2015-02-01

Nanoporous activated carbons (ACs) were prepared from Lapsi (Choerospondias axillaris) seed powder by chemical activation with sodium hydroxide (NaOH) at different NaOH impregnation ratios. The prepared ACs were characterized by Fourier transform-infrared (FTIR) spectroscopy, Raman scattering, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Semi-quantitative information on the surface properties was obtained by estimating iodine number. FTIR spectra showed the presence of oxygenated functional groups such as hydroxyl, carbonyl, and carboxyl in the prepared ACs. Raman scattering showed clear D and G bands in the spectra. The intensity ratio of G and D band peak intensity was ca. 1.39 at lowest NaOH and Lapsi seed powder ratio 0.25:1 showing high graphitic degree. This ratio decreased with increase in the NaOH impregnation ratio and reached minimum ca. 0.94 (comparable with commercial AC) at NaOH and Lapsi seed powder ratio 1:1 demonstrating that higher NaOH impregnation reduces the graphitic structure of the carbon. XRD patterns showed two broad peaks at diffraction angles of approximately 25 and 43 degrees indicating the amorphous structure. Surface properties of the ACs (BET surface area, pore volume, and pore size distributions) were evaluated by nitrogen adsorption-desorption isotherm. Our ACs showed strong methylene blue adsorption property (maximum methylene blue is ca. 200 mg/g). Judging from the iodine number and methylene blue values, structure, and surface areas, it can be concluded that NaOH impregnation ratio is one of the key parameters to tune the surface properties of Lapsi seed stone-based activated carbons.

Applications of Cu{sub 2}O octahedral particles on ITO glass in photocatalytic degradation of dye pollutants under a halogen tungsten lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhai, Wei; Sun, Fengqiang, E-mail: fqsun@scnu.edu.cn; Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University

2013-11-15

Graphical abstract: - Highlights: • Photocatalytic activity of Cu{sub 2}O octahedral microcrystals on ITO glass was studied. • They showed high abilities in degradation of methylene blue in the presence of H{sub 2}O{sub 2}. • H{sub 2}O{sub 2} amount could affect the degradation efficiency. • Such particles could be easily recycled and still kept high activity. • Many dye pollutants and their mixtures could be efficiently degraded. - Abstract: Cu{sub 2}O octahedral microcrystals were prepared on the ITO glass by galvanostatic electrodeposition in CuSO{sub 4} solution with poly(vinylpryrrolidone) as the surfactant. By controlling the electrodeposition time, the microcrystals could bemore » randomly distributed on the ITO glass and separated from each other, resulting in as many as possible (1 1 1) crystalline planes were exposed. Such microcrystals immobilized on ITO glass were employed in photodegradation of dye pollutants in the presence of H{sub 2}O{sub 2} under a 150 W halogen tungsten lamp. The photodegradation of methylene blue was taken as an example to evaluate the photocatalytic activities of the octahedral Cu{sub 2}O microcrystals. Effects of electrodeposition time and H{sub 2}O{sub 2} amount on the degradation efficiency was discussed, giving the optimum conditions and the corresponding degradation mechanism. The catalyst showed high ability in degradation of methylene blue, methyl orange, rhodamine B, eosin B and their mixtures under identical conditions.« less

Plasmon-assisted degradation of methylene blue with Ag/AgCl/montmorillonite nanocomposite under visible light.

PubMed

Sohrabnezhad, Sh; Zanjanchi, M A; Razavi, M

2014-09-15

Metal-semiconductor compounds, such as Ag/AgX (X=Cl, Br, I), enable visible light absorption and separation of photogenerated electron-hole through surface plasmon resonance (SPR) effect. However, the electron-hole generated and separated by light are vulnerable in Ag/AgX phase because of the occurrence of secondary recombined. In order to more effectively utilize the SPR photocatalytic effect, nanoparticles are located in a matrix. In this article, Ag/AgCl nanoparticles were synthesized in montmorillonite (MMT) matrix using dispersion method and light irradiation. The structure, composition and optical properties of such material were investigated by transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray diffraction (XRD) and FTIR. Powder X-ray diffraction showed intercalation of Ag/AgCl nanoparticles into the clay layers. The as-prepared plasmonic photocatalyst exhibited an enhanced and stable photoactivity for the degradation of methylene blue (MB) under visible light. The high activity was attributed to the surface plasmon resonance (SPR) exhibited by Ag nanoparticles on the surface of AgCl. The detection of reactive species by radical scavengers displays that O2- and OH- are the main reactive species for the degradation of MB under visible light irradiation. The studies showed that 20 min illumination under visible light can complete degradation of methylene blue (MB), and indicate a high stability of photocatalytic degradation. The mechanism of separation of the photo-generated electrons and holes at the Ag/AgCl-MMT nanocomposite was discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Acid-base treated vermiculite as high performance adsorbent: Insights into the mechanism of cationic dyes adsorption, regeneration, recyclability and stability studies.

PubMed

Stawiński, Wojciech; Węgrzyn, Agnieszka; Dańko, Tomasz; Freitas, Olga; Figueiredo, Sónia; Chmielarz, Lucjan

2017-04-01

Additional treatment with NaOH of acid activated vermiculite results in even higher increase in the adsorption capacity in comparison to samples modified only in acidic solution (first step of activation) with respect to raw material. Optimization of treatment conditions and adsorption capacity for two cationic dyes (methylene blue (MB) and astrazon red (AR)), also as binary mixture, was evaluated. The capacity, based on column studies, increased from 48 ± 2 to 203 ± 4 mg g -1 in the case of methylene blue and from 51 ± 1 to 127 ± 2 mg g -1 in the case of astrazon red on starting and acid-base treated material, respectively. It was shown that adsorption mechanism changes for both cationic dyes after NaOH treatment and it results in decrease of adsorption rate. In binary mixtures methylene blue is bound stronger by adsorbent and astrazon red may be removed in initial stage of adsorption. Extensive studies on desorption/regeneration process proved high efficiency in recyclable use of all materials. Although cation exchange capacity decreases due to acid treatment, after base treatment exchange properties are used more efficiently. On the other hand, increased specific surface area has less significant contribution into the adsorption potential of studied materials. Obtained adsorbents worked efficiently in 7 adsorption-regeneration cycles and loss of adsorption capacity was observed only in two first cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

The photocatalytic degradation of methylene blue by green semiconductor films that is induced by irradiation by a light-emitting diode and visible light.

PubMed

Yang, Chih-Chi; Doong, Ruey-An; Chen, Ku-Fan; Chen, Giin-Shan; Tsai, Yung-Pin

2018-01-01

This study develops a low-energy rotating photocatalytic contactor (LE-RPC) that has Cu-doped TiO 2 films coated on stainless-steel rotating disks, to experimentally evaluate the efficiency of the degradation and decolorization of methylene blue (MB) under irradiation from different light sources (visible 430 nm, light-emitting diode [LED] 460 nm, and LED 525 nm). The production of hydroxyl radicals is also examined. The experimental results show that the photocatalytic activity of TiO 2 that is doped with Cu 2+ is induced by illumination with visible light and an LED. More than 90% of methylene blue at a 10 mg/L concentration is degraded after illumination by visible light (430 nm) for 4 hr at 20 rpm. This study also demonstrates that the quantity of hydroxyl radicals produced is directly proportional to the light energy intensity. The greater the light energy intensity, the greater is the number of hydroxyl radicals produced. The CuO-doped anatase TiO 2 powder was successfully synthesized in this study by a sol-gel method. The catalytic abilities of the stainless-steel film were enhanced in the visible light regions. This study has successfully modified the nano-photocatalytic materials to drop band gap and has also successfully fixed the nano-photocatalytic materials on a substratum to effectively treat dye wastewater in the range of visible light. The results can be useful to the development of a low-energy rotating photocatalytic contactor for decontamination purposes.

Inspecting cracks in foam insulation

NASA Technical Reports Server (NTRS)

Cambell, L. W.; Jung, G. K.

1979-01-01

Dye solution indicates extent of cracking by penetrating crack and showing original crack depth clearly. Solution comprised of methylene blue in denatured ethyl alcohol penetrates cracks completely and evaporates quickly and is suitable technique for usage in environmental or structural tests.

Photocatalytic activity enhancement of anatase-graphene nanocomposite for methylene removal: Degradation and kinetics

NASA Astrophysics Data System (ADS)

Rezaei, Mostafa; Salem, Shiva

2016-10-01

In the present research, the TiO2-graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase-graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10 nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice.

Comparative performance evaluation of Aspergillus lentulus for dye removal through bioaccumulation and biosorption.

PubMed

Kaushik, Prachi; Malik, Anushree

2013-05-01

Dyes used in various industries are discharged into the environment and pose major environmental concern. In the present study, fungal isolate Aspergillus lentulus was utilized for the treatment of various dyes, dye mixtures and dye containing effluent in dual modes, bioaccumulation (employing growing biomass) and biosorption (employing pre-cultivated biomass). The effect of dye toxicity on the growth of the fungal isolate was studied through phase contrast and scanning electron microscopy. Dye biosorption was studied using first and second-order kinetic models. Effects of factors influencing adsorption and isotherm studies were also conducted. During bioaccumulation, good removal was obtained for anionic dyes (100 mg/l), viz. Acid Navy Blue, Fast Red A and Orange-HF dye (99.4 %, 98.8 % and 98.7 %, respectively) in 48 h. Cationic dyes (10 mg/l), viz. Rhodamine B and Methylene Blue, had low removal efficiency (80.3 % [48 h] and 92.7 % [144 h], respectively) as compared to anionic dyes. In addition to this, fungal isolate showed toxicity response towards Methylene Blue by producing larger aggregates of fungal pellets. To overcome the limitations of bioaccumulation, dye removal in biosorption mode was studied. In this mode, significant removal was observed for anionic (96.7-94.3 %) and cationic (35.4-90.9 %) dyes in 24 h. The removal of three anionic dyes and Rhodamine B followed first-order kinetic model whereas removal of Methylene Blue followed second-order kinetic model. Overall, fungal isolate could remove more than 90 % dye from different dye mixtures in bioaccumulation mode and more than 70 % dye in biosorption mode. Moreover, significant color removal from handmade paper unit effluent in bioaccumulation mode (86.4 %) as well as in biosorption mode (77.1 %) was obtained within 24 h. This study validates the potential of fungal isolate, A. lentulus, to be used as the primary organism for treating dye containing wastewater.

Effect of taxol from Pestalotiopsis mangiferae on A549 cells-In vitro study

PubMed Central

Kathiravan, Govindarajan; Sureban, Sripathi M.

2009-01-01

Pestalotiopsis mangiferae Coelomycete fungi were used to examine the production of taxol. The taxol isolated from this fungus is biologically active against cancer cell lines were investigated for its antiproliferative activity in human Non Small Cell Lung Cancer A549 cells. The results showed that the methylene chloride extraction of Pestalotiopsis mangiferae inhibited the proliferation of A 549 cells as measured by MTT and Trypan blue assay. Flow cytometric analysis showed that methylene chloride extraction of Pestalotiopsis mangiferae blocked cell cycle progression in G0/G1 phase. In addition fungal taxol induced A549 cell apoptosis as determined by propidium iodide staining. Further the percentage of LDH release was increased at increasing concentrations which is a measure of cell death. The levels of sialic acid levels and DNA, RNA and protein levels were decreased after treatment with methylene chloride extraction of Pestalotiopsis mangiferae. We suggests that methylene chloride extraction of Pestalotiopsis mangiferae might be considered for future therapeutic application with further studies against lung cancer. PMID:25206246

Effect of taxol from Pestalotiopsis mangiferae on A549 cells-In vitro study.

PubMed

Kathiravan, Govindarajan; Sureban, Sripathi M

2009-12-01

Pestalotiopsis mangiferae Coelomycete fungi were used to examine the production of taxol. The taxol isolated from this fungus is biologically active against cancer cell lines were investigated for its antiproliferative activity in human Non Small Cell Lung Cancer A549 cells. The results showed that the methylene chloride extraction of Pestalotiopsis mangiferae inhibited the proliferation of A 549 cells as measured by MTT and Trypan blue assay. Flow cytometric analysis showed that methylene chloride extraction of Pestalotiopsis mangiferae blocked cell cycle progression in G0/G1 phase. In addition fungal taxol induced A549 cell apoptosis as determined by propidium iodide staining. Further the percentage of LDH release was increased at increasing concentrations which is a measure of cell death. The levels of sialic acid levels and DNA, RNA and protein levels were decreased after treatment with methylene chloride extraction of Pestalotiopsis mangiferae. We suggests that methylene chloride extraction of Pestalotiopsis mangiferae might be considered for future therapeutic application with further studies against lung cancer.

Laparoscopic Filshie clip sterilization and selective use of the methylene blue dye test.

PubMed

Karoshi, Mahantesh; Yoong, Wai

2004-01-01

In laparoscopic Filshie clip sterilization, difficulties may arise in identifying the length of the fallopian tube, with the possibility of failure of sterilization. This article describes a novel intraoperative method of demonstrating adequate tubal closure.

Enhancement of anti-stokes sensitized luminescence in AgCl(I) crystals in the presence of silver nanoparticles

NASA Astrophysics Data System (ADS)

Chung, Nguyen Thi Kim; Egorushina, E. A.; Latyshev, A. N.; Ovchinnikov, O. V.; Smirnov, M. S.; Suvorova, T. I.

2012-01-01

We have observed a significant increase in the intensity with anti-Stokes excitation of recombination luminescence in AgCl(I) microcrystals sensitized by methylene blue molecules in the presence of silver nanoparticles.

Methylene Blue Facilitates Memory Retention in Zebrafish in a Dose-Dependent Manner.

PubMed

Echevarria, David J; Caramillo, Erika M; Gonzalez-Lima, Francisco

2016-12-01

Methylene blue (MB) is an FDA-grandfathered drug with memory-enhancing effects at low doses, but opposite effects at high doses. We investigated the effects of four MB doses (0.1, 0.5, 5.0, or 10.0 μM) on zebrafish memory retention in the T-maze task. After training fish to swim into a certain arm of the T-maze, the fish were placed into a tank containing one of the four MB doses or a control tank containing blue food dye. Subsequently, fish were placed into the T-maze for memory retention testing. Results indicated that MB produced hormetic dose-response effects on memory. Fish that received the 0.5 μM dose performed significantly better at the T-maze than those that received higher doses. Fish who received 5.0 μM did not exhibit a significant difference in performance from control fish, and the fish that received the 10.0 μM dose performed significantly worse than lower doses. These findings support the utility of zebrafish in comparative research and their potential value for testing of MB and other neuropsychopharmacological treatments in animal models of memory disorders.

DNA Electrochemistry with Tethered Methylene Blue

PubMed Central

Pheeney, Catrina G.

2012-01-01

Methylene blue (MB′), covalently attached to DNA through a flexible C12 alkyl linker, provides a sensitive redox reporter in DNA electrochemistry measurements. Tethered, intercalated MB′ is reduced through DNA-mediated charge transport; the incorporation of a single base mismatch at position 3, 10, or 14 of a 17-mer causes an attenuation of the signal to 62 ± 3% of the well-matched DNA, irrespective of position in the duplex. The redox signal intensity for MB′–DNA is found to be least 3-fold larger than that of Nile blue (NB)–DNA, indicating that MB′ is even more strongly coupled to the π-stack. The signal attenuation due to an intervening mismatch does, however, depend on DNA film density and the backfilling agent used to passivate the surface. These results highlight two mechanisms for reduction of MB′ on the DNA-modified electrode: reduction mediated by the DNA base pair stack and direct surface reduction of MB′ at the electrode. These two mechanisms are distinguished by their rates of electron transfer that differ by 20-fold. The extent of direct reduction at the surface can be controlled by assembly and buffer conditions. PMID:22512327

Textile Dye Removal from Aqueous Solution using Modified Graphite Waste/Lanthanum/Chitosan Composite

NASA Astrophysics Data System (ADS)

Kusrini, E.; Wicaksono, B.; Yulizar, Y.; Prasetyanto, EA; Gunawan, C.

2018-03-01

We investigated various pre-treatment processes of graphite waste using thermal, mechanical and chemical methods. The aim of this work is to study the performance of modified graphite waste/lanthanum/chitosan composite (MG) as adsorbent for textile dye removal from aqueous solution. Effect of graphite waste resources, adsorbent size and lanthanum concentration on the dye removal were studied in batch experiments. Selectivity of MG was also investigated. Pre-heated graphite waste (NMG) was conducted at 80°C for 1 h, followed by mechanical crushing of the resultant graphite to 75 μm particle size, giving adsorption performance of ˜58%, ˜67%, ˜93% and ˜98% of the model dye rhodamine B (concentration determined by UV-vis spectroscopy at 554 nm), methyl orange (464 nm), methylene blue (664 nm) and methyl violet (580 nm), respectively from aqueous solution. For this process, the system required less than ˜5 min for adsorbent material to be completely saturated with the adsorbate. Further chemical modification of the pre-treated graphite waste (MG) with lanthanum (0.01 – V 0.03 M) and chitosan (0.5% w/w) did not improve the performance of dye adsorption. Under comparable experimental conditions, as those of the ‘thermal-mechanical-pre-treated-only’ (NMG), modification of graphite waste (MG) with 0.03 M lanthanum and 0.5% w/w chitosan resulted in ˜14%, ˜47%, ˜72% and ˜85% adsorption of rhodamine B, methyl orange, methylene blue and methyl violet, respectively. Selective adsorption of methylene blue at most to ˜79%, followed by methyl orange, methyl violet and rhodamine B with adsorption efficiency ˜67, ˜38, and ˜9% sequentially using MG with 0.03 M lanthanum and 0.5% w/w chitosan.

Experimental and kinetic studies on methylene blue adsorption by coir pith carbon.

PubMed

Kavitha, D; Namasivayam, C

2007-01-01

Varying the parameters such as agitation time, dye concentration, adsorbent dose, pH and temperature carried out the potential feasibility of thermally activated coir pith carbon prepared from coconut husk for removal of methylene blue. Greater percentage of dye was removed with decrease in the initial concentration of dye and increase in amount of adsorbent used. Kinetic study showed that the adsorption of dye on coir pith carbon was a gradual process. Lagergren first-order, second-order, intra particle diffusion model and Bangham were used to fit the experimental data. Equilibrium isotherms were analysed by Langmuir, Freundlich, Dubnin-Radushkevich, and Tempkin isotherm. The adsorption capacity was found to be 5.87 mg/g by Langmuir isotherm for the particle size 250-500 microm. The equilibrium time was found to be 30 and 60 min for 10 and 20 mg/L and 100 min for 30, 40 mg/L dye concentrations, respectively. A maximum removal of 97% was obtained at natural pH 6.9 for an adsorbent dose of 100 mg/50 mL and 100% removal was obtained for an adsorbent dose of 600 mg/50 mL of 10 mg/L dye concentration. The pH effect and desorption studies suggest that chemisorption might be the major mode of the adsorption process. The change in entropy (DeltaS0) and heat of adsorption (DeltaH0) of coir pith carbon was estimated as 117.20 J/mol/K and 30.88 kJ/mol, respectively. The high negative value of change in Gibbs free energy indicates the feasible and spontaneous adsorption of methylene blue on coir pith carbon.

Methylene Blue Partially Rescues Heart Defects in a Drosophila Model of Huntington's Disease.

PubMed

Heidari, Raheleh; Monnier, Véronique; Martin, Elodie; Tricoire, Hervé

2015-01-01

Huntington's disease (HD) is a Polyglutamine disease caused by the presence of CAG repeats in the first exon of Huntingtin (Htt), a large protein with multiple functions. In addition to neurodegeneration of specific brain regions, notably the striatum, HD also shows alterations in peripheral tissues, such as the heart, skeletal muscles or peripheral endocrine glands. Mutant Huntingtin (mHtt)-driven mitochondrial impairment may underlie some of the CNS and peripheral tissues dysfunctions, especially in tissues with high energy demand such as the heart. The aim of this study is to characterize two new inducible Drosophila HD heart models and to assay the therapeutic potential of methylene blue in these HD models. We report the construction of inducible Drosophila HD heart models, expressing two Nter fragments of the protein encompassing either exon 1 or the first 171 amino acids and the characterization of heart phenotypes in vivo. We show that both mHtt fragments are able to impair fly cardiac function with different characteristics. Additionally, expression of mHtt, which was limited to adulthood only, leads to mild heart impairment, as opposed to a strong and age-dependent phenotype observed when mHtt expression was driven during both developmental and adult stages. We report that treatment with methylene blue (MB), a protective compound in mitochondria-related diseases, partially protects the fly's heart against mHtt-induced toxicity, but does not rescue neuronal or glial phenotypes in other fly models of HD. This may be linked to its low penetration through the fly's blood-brain barrier. Our data suggest that improvement of mitochondrial function by MB, or related compounds, could be an efficient therapeutic strategy to prevent cardiac failure in HD patients.

A hydrothermal peroxo method for preparation of highly crystalline silica-titania photocatalysts.

PubMed

Krivtsov, Igor; Ilkaeva, Marina; Avdin, Viacheslav; Khainakov, Sergei; Garcìa, Jose R; Ordòñez, Salvador; Dìaz, Eva; Faba, Laura

2015-04-15

A new completely inorganic method of preparation of silica-titania photocatalyst has been described. It has been established that the addition of silica promotes crystallinity of TiO2 anatase phase. Relative crystallinity and TiO2 crystal size in the silica-titania particles increase with the silica content until SiO2/TiO2 molar ratio of 0.9, but at higher molar ratios they start to decrease. The single-source precursor containing peroxo titanic (PTA) and silicic acids has been proved to be responsible for high crystallinity of TiO2 encapsulated into amorphous silica. It has been proposed that peroxo groups enhance rapid formation of crystalline titania seeds, while silica controls their growth. It has been concluded from the TEM that the most morphologically uniform anatase crystallites covered with SiO2 particles are prepared at SiO2/TiO2 molar ratio of 0.4. This sample, according to (29)Si NMR, also shows the high content of hydroxylated silica Q(3) and Q(2) groups, and it is the most photocatalytically active in UV-assisted decomposition of methylene blue among the tested materials. It has been determined that the increase in the amount of the condensed Q(4) silica in the mixed oxides leads to the decrease in photocatalytic performance of the material, despite its better crystallinity. High crystallinity, low degree of incorporation of Ti atoms in SiO2 in the mixed oxide and adsorption of methylene blue in the vicinity of photoactive sites on the hydroxylated silica have been considered as the main factors determining the high degradation degree of methylene blue in the presence of silica-titania. Copyright © 2014 Elsevier Inc. All rights reserved.

Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

NASA Astrophysics Data System (ADS)

Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

2016-04-01

In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

Novel electrochemical immunoassay for quantitative monitoring of biotoxin using target-responsive cargo release from mesoporous silica nanocontainers.

PubMed

Zhang, Bing; Liu, Bingqian; Liao, Jiayao; Chen, Guonan; Tang, Dianping

2013-10-01

A novel homogeneous immunoassay protocol was designed for quantitative monitoring of small molecular biotoxin (brevetoxin B, PbTx-2, as a model) by using target-responsive cargo release from polystyrene microsphere-gated mesoporous silica nanocontainer (MSN). Initially, monoclonal mouse anti-PbTx-2 capture antibody was covalently conjugated onto the surface of MSN (mAb-MSN), and the electroactive cargo (methylene blue, MB) was then trapped in the pores of mAb-MSN by using aminated polystyrene microspheres (APSM) based on the electrostatic interaction. Upon addition of target PbTx-2, the positively charged APSM was displaced from the negatively charged mAb-MSN because of the specific antigen-antibody reaction. Thereafter, the molecular gate was opened, and the trapped methylene blue was released from the pores. The released methylene blue could be monitored by using a square wave voltammetry (SWV) in a homemade microelectrochemical detection cell. Under optimal conditions, the SWV peak current increased with the increasing of PbTx-2 concentration in the range from 0.01 to 3.5 ng mL(-1) with a detection limit (LOD) of 6 pg mL(-1) PbTx-2 at the 3Sblank criterion. Intra- and interassay coefficients of variation with identical batches were ≤6% and 9.5%, respectively. The specificity and sample matrix interfering effects were acceptable. The analysis in 12 spiked seafood samples showed good accordance between results obtained by the developed immunoassay and a commercialized enzyme-linked immunosorbent assay (ELISA) method. Importantly, the target-responsive controlled release system-based electrochemical immunoassay (CRECIA) offers a promising scheme for the development of advanced homogeneous immunoassay without the sample separation and washing procedure.

Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

PubMed

Skucha-Nowak, Małgorzata; Machorowska-Pieniążek, Agnieszka; Tanasiewicz, Marta

2016-01-01

The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

Nanomolar determination of 4-nitrophenol based on a poly(methylene blue)-modified glassy carbon electrode.

PubMed

Giribabu, Krishnamoorthy; Suresh, Ranganathan; Manigandan, Ramadoss; Munusamy, Settu; Kumar, Sivakumar Praveen; Muthamizh, Selvamani; Narayanan, Vengidusamy

2013-10-07

A poly(methylene blue)-modified glassy carbon electrode (PMB/GCE) was fabricated by electropolymerisation of methylene blue on a GCE and further utilized to investigate the electrochemical determination of 4-nitrophenol (4-NP) by cyclic voltammetry (CV), differential pulse voltammetry and chronocoulometry. The morphology of the PMB on GCE was examined using a scanning electron microscope (SEM). An oxidation peak of 4-NP at the PMB modified electrode was observed at 0.28 V, and in the case of bare GCE, no oxidation peak was observed, which indicates that PMB/GCE exhibits a remarkable effect on the electrochemical determination of 4-NP. Due to this remarkable effect of PMB/GCE, a sensitive and simple electrochemical method was proposed for the determination of 4-NP. The effect of the scan rate and pH was investigated to determine the optimum conditions at which the PMB/GCE exhibits a higher sensitivity with a lower detection limit. Moreover, kinetic parameters such as the electron transfer number, proton transfer number and standard heterogeneous rate constant were calculated. Under optimum conditions, the oxidation current of 4-NP is proportional to its concentration in the range of 15-250 nM with a correlation coefficient of 0.9963. The detection limit was found to be 90 nM (S/N = 3). The proposed method based on PMB/GCE is simple, easy and cost effective. To further confirm its possible application, the proposed method was successfully used for the determination of 4-NP in real water samples with recoveries ranging from 97% to 101.6%. The interference due to sodium, potassium, calcium, magnesium, copper, zinc, iron, sulphate, carbonate, chloride, nitrate and phosphate was found to be almost negligible.

N-acetylcysteine, Ascorbic Acid, and Methylene Blue for the Treatment of Aluminium Phosphide Poisoning: Still Beneficial?

PubMed Central

Gheshlaghi, Farzad; Lavasanijou, Mohamad Reza; Moghaddam, Noushin Afshar; Khazaei, Majid; Behjati, Mohaddeseh; Farajzadegan, Ziba; Sabzghabaee, Ali Mohammad

2015-01-01

Objectives: Intentional and accidental intoxication with aluminium phosphide (ALP) remains a clinical problem, especially in the Middle East region. Considering the high mortality rate besides lack of any recommended first option drug for its treatment, this study was aimed to compare the therapeutic effects of N-acetylcysteine (NAC), vitamin C (Vit C), and methylene blue; both in isolate and also in combination, for the treatment of ALP intoxication in a rat model. Materials and Methods: In this experimental animal study, 80 male Wistar rats in eight groups were intoxicated with ALP (12.5 mg/kg) and treated with a single dose of NAC (100 mg/kg) or Vit C (500–1,000 mg/kg) or methylene blue (1 mg/kg/5 min, 0.1%) or two of these agents or all three of them (controls were not treated). Rats were monitored regarding the parameters of drug efficacy as increased survival time and reduced morbidity and mortality rate for 3 consecutive days to ensure toxin neutralization. Macroscopic changes were recorded and biopsy sections were taken from brain, cerebellum, kidney, liver, and heart for microscopic evaluation regarding cellular hypoxia. Results: The mean survival times of rats exposed to ALP and treated with VitC + NAC was 210.55±236.22 minutes. In analysis of survival times, there was a significant difference between Group 5 which received VitC + NAC and the other groups (P < 0.01). Serum magnesium levels after death were higher than normal (P = 0.01). Conclusions: Despite the higher survival rate of antioxidant-treated rats compared with controls, this difference was not statistically significant. PMID:26862259

In vitro modulation of cytochrome P450 reductase supported indoleamine 2,3-dioxygenase activity by allosteric effectors cytochrome b(5) and methylene blue.

PubMed

Pearson, Josh T; Siu, Sophia; Meininger, David P; Wienkers, Larry C; Rock, Dan A

2010-03-30

Indoleamine 2,3-dioxygenase (IDO) is a heme-containing dioxygenase involved in the degradation of several indoleamine derivatives and has been indicated as an immunosuppressive. IDO is an attractive target for therapeutic intervention in diseases which are known to capitalize on immune suppression, including cancer, HIV, and inflammatory diseases. Conventionally, IDO activity is measured through chemical reduction by the addition of ascorbate and methylene blue. Identification of potential coenzymes involved in the reduction of IDO in vivo should improve in vitro reconstitution systems used to identify potential IDO inhibitors. In this study we show that NADPH-cytochrome P450 reductase (CPR) is capable of supporting IDO activity in vitro and that oxidation of l-Trp follows substrate inhibition kinetics (k(cat) = 0.89 +/- 0.04 s(-1), K(m) = 0.72 +/- 0.15 microM, and K(i) = 9.4 +/- 2.0 microM). Addition of cytochrome b(5) to CPR-supported l-Trp incubations results in modulation from substrate inhibition to sigmoidal kinetics (k(cat) = 1.7 +/- 0.3 s(-1), K(m) = 1.5 +/- 0.9 microM, and K(i) = 1.9 +/- 0.3). CPR-supported d-Trp oxidations (+/-cytochrome b(5)) exhibit Michaelis-Menten kinetics. Addition of methylene blue (minus ascorbate) to CPR-supported reactions resulted in inhibition of d-Trp turnover and modulation of l-Trp kinetics from allosteric to Michaelis-Menten with a concurrent decrease in substrate affinity for IDO. Our data indicate that CPR is capable of supporting IDO activity in vitro and oxidation of tryptophan by IDO displays substrate stereochemistry dependent atypical kinetics which can be modulated by the addition of cytochrome b(5).

The effect of titanium dioxide (TiO2) nano-objects, and their aggregates and agglomerates greater than 100nm (NOAA) on microbes under UV irradiation.

PubMed

Yamada, Ikuho; Nomura, Kazuki; Iwahashi, Hitoshi; Horie, Masanori

2016-01-01

Today, nanoparticles are used in many products. One of the most common nanoparticles is titanium dioxide (TiO2). These particles generate reactive oxygen species (ROS) upon UV irradiation. Although nanoparticles are very useful in many products, there are concerns about their biological and ecological effects when released into the environment. Thus, it was assessed that the effect of TiO2 nano-objects, and their aggregates and agglomerates greater than 100nm (NOAA) on microbes under UV irradiation by using Escherichia coli and Saccharomyces cerevisiae. ROS generation was evaluated by adding TiO2 nanoparticles and methylene blue to distilled water. We also assessed growth inhibition by adding TiO2 nanoparticles and microbes in minimal agar medium. Moreover, microbial inactivation was assessed by adding TiO2 nanoparticles and microbes to PBS. Upon UV irradiation, TiO2-NOAAs decomposed methylene blue and generated ROS. TiO2-NOAAs also decomposed methylene blue in minimal agar medium under UV irradiation; however, they did not inhibit microbial growth. Surprisingly, TiO2-NOAAs in the medium protect microbes from UV irradiation as colony formation was observed only near TiO2-NOAAs. In PBS, TiO2-NOAAs did not inactivate microbes but instead protected microbes from lethal UV irradiation. These results suggest that the amount of ROS generated by TiO2-NOAAs is not enough to inactivate microbes. In fact, our results suggest that TiO2-NOAAs may protect microbes from UV irradiations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Target-regulated proximity hybridization with three-way DNA junction for in situ enhanced electronic detection of marine biotoxin based on isothermal cycling signal amplification strategy.

PubMed

Liu, Bingqian; Chen, Jinfeng; Wei, Qiaohua; Zhang, Bing; Zhang, Lan; Tang, Dianping

2015-07-15

A new signal amplification strategy based on target-regulated DNA proximity hybridization (TRPH) reaction accompanying formation of three-way DNA junction was designed for electronic detection of Microcystin-LR (MC-LR used in this case), coupling with junction-induced isothermal cycling signal amplification. Initially, a sandwiched-type immunoreaction was carried out in a low-cost PCR tube between anti-MC-LR mAb1 antibody-labeled DNA1 (mAb1-DNA1) and anti-MC-LR mAb2-labeled DNA2 (mAb2-DNA2) in the presence of target to form a three-way DNA junction. Then, the junction could undergo an unbiased strand displacement reaction on an h-like DNA nanostructure-modified electrode (labeled with methylene blue redox tag on the short DNA strand), thereby resulting in the dissociation of methylene blue-labeled signal DNA from the electrode. The newly formed double-stranded DNA could be cleaved again by exonuclease III, and the released three-way DNA junction retriggered the strand-displacement reaction with h-like DNA nanostructures for junction recycling. During the strand-displacement reaction, numerous methylene blue-labeled DNA strands were far away from the electrode, thus decreasing the detectable electrochemical signal within the applied potentials. Under optimal conditions, the TRPH-based immunosensing system exhibited good electrochemical responses for detecting target MC-LR at a concentration as low as 1.0ngkg(-1) (1.0ppt). Additionally, the precision, reproducibility, specificity and method accuracy were also investigated with acceptable results. Copyright © 2015 Elsevier B.V. All rights reserved.

Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

NASA Astrophysics Data System (ADS)

Darmawan, A.; Widiarsih

2018-04-01

The manufacture of membrane support from cobalt aluminium pillared clay has been conducted. This research was conducted by mixing a clay suspension with pillared solution prepared from the mixture of Co(NO3)2.6H2O and AlCl3.6H2O. The molar ratio between Al and Co was 75:25 and the ratio of [OH-]/[metal] was 2. The clay suspension was stirred for 24 hours at room temperature, filtered and dried. The dried clay was then calcined at 200°C, 300°C and 400°C with a ramp rate of 2°C/min. Aluminium-cobalt-pillared clay was then characterized by XRD and GSA and moulded become a membrane support for subsequent tests on dye filtration. The XRD analysis showed that basal spacing (d 001) value of aluminium cobalt was 19.49 Å, which was higher than the natural clay of 15.08Å however, the basal spacing decreased with increasing calcination temperature. The result of the GSA analysis showed that the pore diameter of the aluminium cobalt pillared clay membrane was almost the same as that of natural clay that were 34.5Å and 34.2Å, respectively. Nevertheless, the pillared clay has a more uniform pore size distribution. The results of methylene blue filtration measurements demonstrated that the membrane filter support could well which shown by a clear filtrate at all concentrations tested. The value of rejection and flux decreased with the increasing concentration of methylene blue. The values of dye rejection and water flux reached 99.89% and 5. 80 x 10-6 kg min-1, respectively but they decreased with increasing concentration of methylene blue. The results of this study indicates that the aluminium-pillared clay cobalt could be used as membrane materials especially for ultrafiltration.

Comparison of Hydrogen Sulfide Analysis Techniques

ERIC Educational Resources Information Center

Bethea, Robert M.

1973-01-01

A summary and critique of common methods of hydrogen sulfide analysis is presented. Procedures described are: reflectance from silver plates and lead acetate-coated tiles, lead acetate and mercuric chloride paper tapes, sodium nitroprusside and methylene blue wet chemical methods, infrared spectrophotometry, and gas chromatography. (BL)

Systemic reduction of rice blast by means of photosensitizers

USDA-ARS?s Scientific Manuscript database

Acquired disease resistance of plants may be induced by exogenous reactive oxygen species or their sources. Certain compounds (photosensitizers) produce ROS at the expense of light energy. This study used photodynamic dyes bengal rose and methylene blue, which yield singlet oxygen, and mercaptopyrid...

Adsorption studies of methylene blue and gentian violet on sugarcane bagasse modified with EDTA dianhydride (EDTAD) in aqueous solutions: kinetic and equilibrium aspects.

PubMed

Gusmão, Karla Aparecida Guimarães; Gurgel, Leandro Vinícius Alves; Melo, Tânia Márcia Sacramento; Gil, Laurent Frédéric

2013-03-30

In this study the adsorption of cationic dyes by modified sugarcane bagasse with EDTA dianhydride (EB) was examined using methylene blue (MB) and gentian violet (GV) as model compounds in aqueous single solutions. The synthesized adsorbent (EB) was characterized by FTIR, elemental analysis, and BET. The capacity of EB to adsorb dyes was evaluated at different contact times, pH values, and initial dye concentrations. According to the obtained results, the adsorption processes could be described by a pseudo-second-order kinetic model. The adsorption isotherms were well fitted by the Langmuir model. Maximum adsorption capacities for MB and GV on EB were found to be 202.43 and 327.83 mg/g, respectively. The free energy change during adsorption of MB and GV was found to be -22.50 and -24.21 kJ/mol, respectively, suggesting that chemisorption is the main mechanism controlling the adsorption process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution.

PubMed

Sajab, Mohd Shaiful; Chia, Chin Hua; Zakaria, Sarani; Jani, Saad Mohd; Ayob, Mohd Khan; Chee, Kah Leong; Khiew, Poi Sim; Chiu, Wee Siong

2011-08-01

Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characteristics of low-slope streams that affect O2 transfer rates

USGS Publications Warehouse

Parker, Gene W.; Desimone, Leslie A.

1991-01-01

Multiple-regression techniques were used to derive the reaeration coefficients estimating equation for low sloped streams: K2 = 3.83 MBAS-0.41 SL0.20 H-0.76, where K2 is the reaeration coefficient in base e units per day; MBAS is the methylene blue active substances concentration in milligrams per liter; SL is the water-surface slope in foot per foot; and H is the mean-flow depth in feet. Fourteen hydraulic, physical, and water-quality characteristics were regressed against 29 measured-reaeration coefficients for low-sloped (water surface slopes less than 0.002 foot per foot) streams in Massachusetts and New York. Reaeration coefficients measured from May 1985 to October 1988 ranged from 0.2 to 11.0 base e units per day for 29 low-sloped tracer studies. Concentration of methylene blue active substances is significant because it is thought to be an indicator of concentration of surfactants which could change the surface tension at the air-water interface.

Modified microwave method for the synthesis of visible light-responsive TiO2/MWCNTs nanocatalysts

PubMed Central

2013-01-01

Recently, TiO2/multi-walled carbon nanotube (MWCNT) hybrid nanocatalysts have been a subject of high interest due to their excellent structures, large surface areas and peculiar optical properties, which enhance their photocatalytic performance. In this work, a modified microwave technique was used to rapidly synthesise a TiO2/MWCNT nanocatalyst with a large surface area. X-ray powder diffraction, field-emission scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller measurements were used to characterise the structure, morphology and the surface area of the sample. The photocatalytic activity of the hybrid nanocatalysts was evaluated through a comparison of the degradation of methylene blue dye under irradiation with ultraviolet and visible light. The results showed that the TiO2/MWCNT hybrid nanocatalysts degraded 34.9% of the methylene blue (MB) under irradiation with ultraviolet light, whereas 96.3% of the MB was degraded under irradiation with visible light. PMID:23919496

Nitric oxide synthase and soluble guanylate cyclase are involved in spinal cord wind-up activity of monoarthritic, but not of normal rats.

PubMed

Laurido, Claudio; Hernández, Alejandro; Constandil, Luis; Pelissier, Teresa

2003-11-27

While increasing evidence points to a role for the nitric oxide (NO)/cyclic guanosine 3,5-monophosphate (GMPc) cascade in hyperalgesia and allodynia, participation of the NO/GMPc pathway in synaptic processing in the spinal cord, i.e. wind-up activity, is less clear. We studied the effects of intrathecal administration of Nomega-nitro-L-arginine methyl ester (L-NAME) and methylene blue, inhibitors of NO synthase and guanylate cyclase respectively, on wind-up activity developed in a C-fiber reflex response paradigm. 5, 10 and 20 microg i.t. of L-NAME or methylene blue did not modify spinal wind-up in normal rats, while a dose-dependent inhibition of wind-up was observed in monoarthritic rats. Results suggest that the NO/GMPc pathway plays a non-significant role in wind-up activity evoked in normal animals, while it may be essential in chronic pain processing.

Effect of CO₂ flow rate on the Pinang frond-based activated carbon for methylene blue removal.

PubMed

Herawan, S G; Ahmad, M A; Putra, A; Yusof, A A

2013-01-01

Activated carbons are regularly used the treatment of dye wastewater. They can be produced from various organics materials having high level of carbon content. In this study, a novel Pinang frond activated carbon (PFAC) was produced at various CO₂ flow rates in the range of 150-600 mL/min at activation temperature of 800°C for 3 hours. The optimum PFAC sample is found on CO₂ flow rate of 300 mL/min which gives the highest BET surface area and pore volume of 958 m²/g and 0.5469 mL/g, respectively. This sample shows well-developed pore structure with high fixed carbon content of 79.74%. The removal of methylene blue (MB) by 95.8% for initial MB concentration of 50 mg/L and 72.6% for 500 mg/L is achieved via this sample. The PFAC is thus identified to be a suitable adsorbent for removing MB from aqueous solution.

Removal of methylene blue by invasive marine seaweed: Caulerpa racemosa var. cylindracea.

PubMed

Cengiz, Sevilay; Cavas, Levent

2008-05-01

Caulerpa racemosa var. cylindracea is one of the well-known invasive species in the Mediterranean Sea. In the present study, dried biomass of C. racemosa var. cylindracea was shown to have adsorption capacity for methylene blue. The adsorption reached equilibrium at 90 min for all studied concentrations (5-100mg/L). The pseudo-second-order model is well in line with our experimental results. There was a sharp increase in the adsorbed dye amount per adsorbent amount from 3.3 to 16.7 g/L, then a slight increase up to 66.7 g/L was observed. Langmuir and Freundlich's models were applied to the data related to adsorption isotherm. According to Langmuir's model data, the observed maximum adsorption capacity (qm) was 5.23 mg/g at 18 degrees C. The enthalpy of adsorption was found to be 33 kJ/mol, which indicated a chemical adsorption between dye molecules and C. racemosa var. cylindracea functional groups.

Cr(OH)3-NPs-CNC hybrid nanocomposite: a sorbent for adsorptive removal of methylene blue and malachite green from solutions.

PubMed

Nekouei, Farzin; Nekouei, Shahram; Keshtpour, Farzaneh; Noorizadeh, Hossein; Wang, Shaobin

2017-11-01

In this article, Cr(OH) 3 nanoparticle-modified cellulose nanocrystal (CNC) as a novel hybrid nanocomposite (Cr(OH) 3 -NPs-CNC) was prepared by a simple procedure and used as a sorbent for adsorptive removal of methylene blue (MB) and malachite green (MG) from aqueous solution. Different kinetic models were tested, and the pseudo-second-order kinetic model was found more suitable for the MB and MG adsorption processes. The BET and Langmuir models were more suitable for the adsorption processes of MB and MG. Thermodynamic studies suggested that the adsorption of MB and MG onto Cr(OH) 3 -NPs-CNC nanocomposite was a spontaneous and endothermic process. The maximum adsorption capacities for MB and MG were reached 106 and 104 mg/g, respectively, which were almost two times higher than unmodified CNC. The chemical stability and leaching tests of the Cr(OH) 3 -NPs-CNC hybrid nanocomposite showed that only small amounts of chromium were leached into the solution.

Studies on hydrothermal synthesis of photolumniscent rare earth (Eu3+ & Tb3+) doped NG@FeMoO4 for enhanced visible light photodegradation of methylene blue dye

NASA Astrophysics Data System (ADS)

Singh, R.; Kumar, M.; Khajuria, H.; Sharma, S.; Sheikh, H. Nawaz

2018-02-01

FeMoO4 nanorods and their rare earth (Eu3+ and Tb3+) doped composites with nitrogen doped graphene (NG) were synthesized by facile hydrothermal method in aqueous medium. X-ray diffraction (XRD) analysis of the as-synthesized samples was done to study the phase purity and crystalline nature. FTIR and Raman Spectroscopy have been studied for investigating the bonding in nanostructures. The surface morphology of the samples was investigated with field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The photolumniscent nature of the samples was investigated by the using the fluorescence spectrophotometer. The photocatalytic degradation efficiency of the prepared pure FeMoO4 and its rare earth doped composites with nitrogen doped graphene was evaluated as function of visible light irradiation versus concentration of methylene blue (MB dye). The prepared nanocomposites show enhanced photocatalytic efficiency as compared to the bare FeMoO4 nanorods.

Synthesis of ZnO/Zn nano photocatalyst using modified polysaccharides for photodegradation of dyes.

PubMed

Lin, Shi-Tsung; Thirumavalavan, Munusamy; Jiang, Ting-Yan; Lee, Jiunn-Fwu

2014-05-25

A complete set of experiments in two aspects of studies combining the various factors affecting both the preparation and photocatalytic activity of ZnO/Zn nanocomposite obtained using corn starch and cellulose (native and modified) as chelating agents for the photodegradation of methylene blue, and congo red was carried out and discussed. The resulting ZnO/Zn nanoparticles obtained using modified polysaccharides exhibited super catalytic capability. The ZnO/Zn nanoparticles possessed favored surface area (11.8443-15.7100m(2)/g) and pore size (12.3473-13.7453nm). The photocatalytic degradation of nano ZnO/Zn was directly proportional to the surface area of nano ZnO/Zn. Regardless of the dye pollutants, nano ZnO/Zn obtained using modified corn starch showed enhanced catalytic activity than that of cellulose and methylene blue had comparatively faster degradation rate. Our findings shed light on the optimization of both preparation conditions of photocatalysts and their photocatalytic experimental conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cellular and Molecular Actions of Methylene Blue in the Nervous System

PubMed Central

Oz, Murat; Lorke, Dietrich E.; Hasan, Mohammed; Petroianu, George A.

2010-01-01

Methylene Blue (MB), following its introduction to biology in the 19th century by Ehrlich, has found uses in various areas of medicine and biology. At present, MB is the first line of treatment in methemoglobinemias, is used frequently in the treatment of ifosfamide-induced encephalopathy, and is routinely employed as a diagnostic tool in surgical procedures. Furthermore, recent studies suggest that MB has beneficial effects in Alzheimer's disease and memory improvement. Although the modulation of the cGMP pathway is considered the most significant effect of MB, mediating its pharmacological actions, recent studies indicate that it has multiple cellular and molecular targets. In the majority of cases, biological effects and clinical applications of MB are dictated by its unique physicochemical properties including its planar structure, redox chemistry, ionic charges, and light spectrum characteristics. In this review article, these physicochemical features and the actions of MB on multiple cellular and molecular targets are discussed with regard to their relevance to the nervous system. PMID:19760660

A novel management of streptococcal pharyngotonsillar infections by laser-activated silver nanoparticles and methylene blue conjugate, in vitro study.

PubMed

Kassab, Ahmed; Dabous, Ola; Morsy, Mona

2017-09-01

Species of Streptococcus are classified based on their hemolytic properties into alpha and beta types. And, since antimicrobial drug resistance is an increasingly problematic issue, the efforts to develop modalities that would overcome this obstacle and avoid antibiotic side effects is an ongoing challenge. 20 patients from both sexes were selected. The isolated organisms were identified according to standard laboratory methods. Bacterial Cultures were subjected to the low-level diode laser (660 nm), methylene blue (MB) as a photosensitizing agent and for silver nanoparticles. All the experimental groups showed statistically lower values of CFU/ml than the positive control group. The photoactivated MB, silver nanoparticles conjugate showed the maximum inhibitory effect on Streptococci, which opens a gate to further investigation of such a promising protocol to establish a safe and efficient method of management for resistant cases of streptococcal tonsillar infections. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of the surface modification of silver nanoparticles on the surface-enhanced Raman spectroscopy of methylene blue for borohydride-reduced silver colloid

NASA Astrophysics Data System (ADS)

Dong, Xiao; Gu, Huaimin; Kang, Jian; Yuan, Xiaojuan; Wu, Jiwei

2010-12-01

The paper further investigated the relationship between the modification of the surface chemistry and the enhancement mechanisms of borohydride-reduced silver particles (BRSC). The bands of residual ions die down while the anomalous bands increase gradually with the increasing of the concentration of Cl - and Br -. It means the residual ions are displaced gradually by the added Cl - or Br - and the two halides can lead to the aggregation of the BRSC to a certain extent. However, the most strongly binding anions - I -, cannot cause any aggregation of silver particles. From the detection of methylene blue (MB), the relationship between the modification of silver surface chemistry and the enhancement mechanisms was discussed. Chloride gives the greatest enhancement while the iodide gives the lowest enhancement among the different kinds of anions. There are also some anomalous bands in the SERS spectra of MB, and these anomalous bands were given rational explanation in this paper.

Growth and photocatalytic properties of Sb-doped ZnO nanoneedles by hydrothermal process

NASA Astrophysics Data System (ADS)

Abaker, M.; Umar, Ahmad; Al-Sayari, S. A.; Dar, G. N.; Faisal, M.; Kim, S. H.; Hwang, S. W.

2011-10-01

This paper reports a facile hydrothermal synthesis of Sb-doped ZnO nanoneedles by using aqueous mixtures of zinc chloride, antimony (Sb) chloride, hexamethylenetetramine (HMTA) and ammonium hydroxide at low temperature of 110 °C. The morphological characterizations of as-synthesized nanoneedles were done by field emission scanning electron microscopy (FESEM) which reveals that the nanoneedles are grown in large-quantity and arranged in such a special manner that they made flower-like morphologies. The structural characterization of as-synthesized nanoneedles was investigated by X-ray diffraction (XRD) pattern which confirm the well-crystalline and wurtzite hexagonal phase of as-synthesized products. The compositional characterization of as-synthesized nanoneedles was characterized by energy dispersive spectroscopy (EDS), which verify that the synthesized nanoneedles are composed of zinc, Sb and oxygen. For application point of view, the synthesized nanoneedles were used as photocatalyst for photocatalytic degradation of methylene blue (MBB) and it was found that it exhibit good photocatalytic properties towards the photocatalytic degradation of methylene blue.

Degradation of methylene blue using pillared TiO2 on de-oiled spent bleaching clay

NASA Astrophysics Data System (ADS)

Hindryawati, N.; Panggabean, A. S.; Fadillah, N. D.; Erwin; Daniel

2018-04-01

Degradation of methylene blue (MB) using pillared TiO2 onto spent bleaching clay has been conducted. Activation of deoiled spent bleaching clay (DSBC) has been done using acid, followed by pillarization with TiO2 using rarasaponin from Klerak fruit as surfactant. From the X-ray diffraction results show the mineral on DSBC is rectorite with dioctahedral mica layer and dioctahedral smectite with ratio 2:1. This molecule have formula Na.Al4(Si, Al)8.O20.(OH)4. H2O and after calcinations the pattern TiO2 was appearance at 2θ: 27.4460°, 36.0850°, 54.3216° and 56.6403°. In order to test the catalytic performance of Ti-DSBC for photodegradation of MB under UV light was conducted under several reaction conditions. The highest degradation of MB was 90 % within 50 minutes and Ti-DSBC can be reused until 5 cycles with percent degradation MB was 84 %.

Peach gum for efficient removal of methylene blue and methyl violet dyes from aqueous solution.

PubMed

Zhou, Li; Huang, Jiachang; He, Benzhao; Zhang, Faai; Li, Huabin

2014-01-30

This study investigated the potential use of natural peach gum (PG) as alternative adsorbent for the removal of dyes from aqueous solutions. The PG showed high adsorption capacities and selectivity for cationic dyes (e.g., methylene blue (MB) and methyl violet (MV)) in the pH range 6-10. 98% of MB and MV could be adsorbed within 5 min, and both of the adsorptions reached equilibrium within 30 min. The dye uptake process followed the pseudo-second-order kinetic model. The intraparticle diffusion was not the sole rate controlling step. Equilibrium adsorption isotherm data indicated a good fit to the Langmuir isotherm model. Regeneration study revealed that PG could be well regenerated in acid solution. The recovered PG still exhibited high adsorption capacity even after five cycles of desorption-adsorption. On the basis of its excellent adsorption performance and facile availability, PG can be employed as an efficient low cost adsorbent for environmental cleanup. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fluorescence tissue distribution of methylene blue used for photodynamic therapy of Helicobacter Pylori

NASA Astrophysics Data System (ADS)

Millson, Charles E.; Buonaccorsi, Giovanni A.; MacRobert, Alexander J.; Mlkvy, Peter; Bown, Stephen G.

1995-03-01

Helicobacter pylori is associated with a wide range of pathologies in the upper gastrointestinal tract. Current treatments employing antibiotics are disappointing, and an endoscopic PDT might offer a better alternative. Methylene blue is a widely known histological dye and has been in use for photodynamic therapy experimentally for some years. A prospective application of MB is photosensitization of Helicobacter pylori, but little is known about its effect with light on normal mucosa of the stomach. We studied the fluorescence microscopy of the stomachs of 3 ferrets which had been sensitized by oral route with three different concentrations of MB 1 hour prior to sacrifice. MB at all doses was seen to concentrate on the surface of the mucosa and shows little deeper penetration. As Helicobacter lie on the superficial mucosa, this study suggests that oral dosing with MB should sensitize these bacteria. These findings are an important preliminary to an in vivo trial of PDT for the treatment of H pylori.

Fenton-like degradation of Methylene Blue using paper mill sludge-derived magnetically separable heterogeneous catalyst: Characterization and mechanism.

PubMed

Zhou, Guoqiang; Chen, Ziwen; Fang, Fei; He, Yuefeng; Sun, Haili; Shi, Huixiang

2015-09-01

For the paper industry, the disposal and management of the yielded sludge are a considerable challenge. In our work, the paper mill sludge-derived magnetically separable heterogeneous catalyst (PMS-Fe-380) was prepared easily through a facile synthesis method. The morphology and structure of PMS-Fe-380 were fully characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmet-Teller analysis. The catalytic activity of PMS-Fe-380 was evaluated by degradation of Methylene Blue (MB). The reusability and stability of PMS-Fe-380 were evaluated in five repeated runs, which suggested that PMS-Fe-380 manifested excellent stability of catalytic activity. Moreover, leaching tests indicated that the leached iron is negligible (<0.5mg/L). This study provides an alternative environmentally friendly reuse method for paper mill sludge and a novel catalyst PMS-Fe-380 that can be considered as a promising heterogeneous Fenton-like catalyst. Copyright © 2015. Published by Elsevier B.V.

Methylene Blue (Tetramethylthionine Chloride) Influences the Mobility of Adult Neural Stem Cells: A Potentially Novel Therapeutic Mechanism of a Therapeutic Approach in the Treatment of Alzheimer's Disease.

PubMed

van der Ven, Amelie T; Pape, Julius C; Hermann, Dirk; Schloesser, Robert; Genius, Just; Fischer, Nadine; Mößner, Rainald; Scherbaum, Norbert; Wiltfang, Jens; Rujescu, Dan; Benninghoff, Jens

2017-01-01

An interest in neurogenesis in the adult human brain as a relevant and targetable process has emerged as a potential treatment option for Alzheimer's disease and other neurodegenerative conditions. The aim of this study was to investigate the effects of tetramethylthionine chloride (methylene blue, MB) on properties of adult murine neural stem cells. Based on recent clinical studies, MB has increasingly been discussed as a potential treatment for Alzheimer's disease. While no differences in the proliferative capacity were identified, a general potential of MB in modulating the migratory capacity of adult neural stem cells was indicated in a cell mobility assay. To our knowledge, this is the first time that MB could be associated with neural mobility. The results of this study add insight to the spectrum of features of MB within the central nervous system and may be helpful for understanding the molecular mechanisms underlying a potential therapeutic effect of MB.

Green Synthesis of ZnO Nanoparticles by an Alginate Mediated Ion-Exchange Process and a case study for Photocatalysis of Methylene Blue Dye

NASA Astrophysics Data System (ADS)

Keong, Choo Cheng; Sunitha Vivek, Yamini; Salamatinia, Babak; Amini Horri, Bahman

2017-04-01

In this study, zinc oxide (ZnO) was prepared via extrusion-dripping method through an ion exchange mediated process using sodium alginate. The samples were synthesized at 500 °C and 600 °C to study the effect of calcination temperature. The morphology, microstructure and optical activity of the calcined ZnO nanoparticles were analyzed by TGA, FESEM and XRD. It was found that ZnO nanoparticles synthesized at 600 °C was of higher purity with high crystallinity. To enhance the photocatalytic efficiency of zinc oxide, ZnO/NCC films were synthesized at varying ZnO loading fractions of 10 wt%, 15 wt%, 20 wt% and 25 wt% and were evaluated by photodegradation of Methylene blue dye and the highest dye percentage removal is found to be 96% which is obtained at ZnO loadings of 25 wt%. The usage of ion-exchange process has shown promising results in producing ZnO of desirable characteristics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yunping; Zheng, Ran; Han, Zhangang, E-mail: hanzg116@126.com

Two supramolecular hybrids [Ni(mbpy){sub 3}]{sub 2}[V{sub 2}W{sub 4}O{sub 19}]·6H{sub 2}O (1) and [Ni(mbpy){sub 3}]{sub 2}[VW{sub 12}O{sub 40}] (2) (mbpy=4,4′-dimethyl-2,2′-bipyridyl) had been synthesized and characterized. Single crystal X-ray diffraction analyses revealed that the anionic moieties in two hybrids belong to typical Lindqvist and α-Keggin-type structures, respectively. The counter ion [Ni(mbpy){sub 3}]{sup 2+} units were anchored to the polyanions via non-covalent intermolecular interactions. These supramolecular hybrids exhibit reversible adsorption–desorption performance for organic dye methylene blue (MB). Hybrid 2 shows a fast adsorption behavior towards MB and a relatively high value can be reached within 5 min in dark. Both 1 and 2more » are structurally stable and can be easily separated from the reaction system for reuse. - Graphical abstract: Supramolecular hybrids of polytungstates have been synthesized and characterized, which exhibit the reversible adsorption–desorption performance for organic dye methylene blue.« less

Mesoporous-activated carbon prepared from chitosan flakes via single-step sodium hydroxide activation for the adsorption of methylene blue.

PubMed

Marrakchi, F; Ahmed, M J; Khanday, W A; Asif, M; Hameed, B H

2017-05-01

In this work, mesoporous-activated carbon (CSAC) was prepared from chitosan flakes (CS) via single-step sodium hydroxide activation for the adsorption of methylene blue (MB). CSAC was prepared using different impregnation ratios of NaOH:CS (1:1, 2:1, 3:1, and 4:1) at 800°C for 90min. The adsorption performance of CSAC was evaluated for MB at different adsorption variables, such MB initial concentrations (25-400mg/L), solution pH (3-11), and temperature (30-50°C). The adsorption isotherm data of CSAC-MB were well fitted to Langmuir model with a maximum adsorption capacity 143.53mg/g at 50°C. Best representation of kinetic data was obtained by the pseudo-second order model. CSAC exhibited excellent adsorption uptake for MB and can potentially be used for other cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Facile decolorization of methylene blue by morphology-dependence δ-MnO2 nanosheets -modified diatomite

NASA Astrophysics Data System (ADS)

Yu, Ting Ting; Li, Kai Lin; Guo, Xiao Long; Li, Fei; Huang, Jia Mu; Zhang, Yu Xin

2015-12-01

In this work, coscinodiscus-diatomite and melosira-diatomite have been decorated by ultrathin birnessite MnO2 (δ-MnO2) nanosheets through a one-pot hydrothermal method without using any surfactants. The δ-MnO2 nanosheets are observed to grow vertically on the purified melosira-diatomite as well as coscinodiscus-diatomite. Moreover, the two composites exhibit high efficiency for decomposing methylene blue (MB) in the presence of H2O2. The coscinodiscus-diatmite@MnO2 achieves a removal rate of 81.8% (2 h), and yet melosira-diatomite@MnO2 reaches a higher degradation rate of 91.3% in 2 h. Additionally, the effects of catalyst amount, catalysis reaction temperature, preparing time have also been investigated. In principle, the diverse diatomite@MnO2 nanostructures not only present an environmentally friendly and low cost with a good cycling stability, but also offer a simple way for the catalytic degradation of dye waste water in practical applications.

An amperometric new methylene blue N-mediating sensor for hydrogen peroxide based on regenerated silk fibroin as an immobilization matrix for peroxidase.

PubMed

Qian, J; Liu, Y; Liu, H; Yu, T; Deng, J

1996-05-01

A simple and effective procedure was described for the immobilization of peroxidase in regenerated silk fibroin membrane prepared from waste silk. The membranes of regenerated silk fibroin with or without peroxidase, before or after the ethanol treatment, were characterized by ir spectra. An amperometric H202 sensor, based on the immobilized peroxidase in regenerated silk fibroin membrane, in the use of new methylene blue N as an electron transfer mediator, was fabricated. The characteristics of the sensor with respect to linearity, response time, effect of pH and temperature, stability, and reproducibility were investigated. Dependences of Michaelis-Menten constant KMapp on the concentration of the mediator, and the applied potential were also studied and the results were presented. The sensor was highly sensitive to H2O2 with a detection limit of 1.0 x 10(-7)M and with response time of less than 40 s.

Well-ordered structure of methylene blue monolayers on Au(111) surface: electrochemical scanning tunneling microscopy studies.

PubMed

Song, Yonghai; Wang, Li

2009-02-01

Well-ordered structure of methylene blue (MB) monolayers on Au(111) surface has been successfully obtained by controlling the substrate potential. Electrochemical scanning tunneling microscopy (ECSTM) examined the monolayers of MB on Au(111) in 0.1 M HClO(4) and showed long-range ordered, interweaved arrays of MB with quadratic symmetry on the substrate in the potential range of double-layer charging. High-resolution ECSTM image further revealed the details of the MB monolayers structure of c(5 x 5 radical 3)rect and the flat-lying orientation of ad-molecules. The dependence of molecular organization on the substrate potential and the formation mechanism of well-ordered structure on Au(111) surface were investigated in detail. The obtained well-ordered structure at the interface between a metal and an aqueous electrolyte might possibly be used as high-density device for signal memory and templates for the advanced nanopatterning of surfaces. (c) 2008 Wiley-Liss, Inc.

Ultra-thin layer chromatography and surface enhanced Raman spectroscopy on silver nanorod array substrates prepared by oblique angle deposition

NASA Astrophysics Data System (ADS)

Chen, Jing; Abell, Justin; Huang, Yao-wen; Zhao, Yiping

2012-06-01

We demonstrate the potential use of silver nanorod (AgNR) array substrates for on-chip separation and detection of chemical mixtures by ultra-thin layer chromatography (UTLC) and surface enhanced Raman spectroscopy (SERS). The capability of the AgNR substrates to separate different compounds in a mixture was explored using a mixture of the food colorant Brilliant Blue FCF and lactic acid, and the mixtures of Methylene Violet and BSA at various concentrations. After the UTLC process, spatially-resolved SERS spectra were collected along the mobile phase development direction and the intensities of specific SERS peaks from each component were used to generate chromatograms. The AgNR substrates demonstrate the capability of separating Brilliant Blue from lactic acid, as well as revealing the SERS signal of Methylene Violet from the massive BSA background after a simple UTLC step. This technique may have significant practical implications in actual detection of small molecules from complex food or clinical backgrounds.

Application of anaerobic granular sludge for competitive biosorption of methylene blue and Pb(II): Fluorescence and response surface methodology.

PubMed

Shi, Li; Wei, Dong; Ngo, Huu Hao; Guo, Wenshan; Du, Bin; Wei, Qin

2015-10-01

This study assessed the biosorption of anaerobic granular sludge (AGS) and its capacity as a biosorbent to remove Pb(II) and methylene blue (MB) from multi-components aqueous solution. It emerged that the biosorption data fitted well to the pseudo-second-order and Langmuir adsorption isotherm models in both single and binary systems. In competitive biosorption systems, Pb(II) and MB will suppress each other's biosorption capacity. Spectroscopic analysis, including Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy were integrated to explain this interaction. Hydroxyl and amine groups in AGS were the key functional groups for sorption. Three-dimensional excitation-emission matrix (3D-EEM) implied that two main protein-like substances were identified and quenched when Pb(II) or MB were present. Response surface methodology (RSM) confirmed that the removal efficiency of Pb(II) and MB reached its peak when the concentration ratios of Pb(II) and MB achieved a constant value of 1. Copyright © 2015 Elsevier Ltd. All rights reserved.

Facile one-pot synthesis of gold and silver nanocatalysts using edible coconut oil

NASA Astrophysics Data System (ADS)

Meena Kumari, M.; Philip, Daizy

2013-07-01

The use of edible oil for the synthesis of metal nanoparticles by wet chemical method is reported for the first time. The paper presents an environmentally benign bottom up approach for the synthesis of gold and silver nanoparticles using edible coconut oil at 373 K. The formation of silver nanoparticles is signaled by the brownish yellow color and that of gold nanoparticles by the purple color. Fine control over the nanoparticle size and shape from triangular to nearly spherical is achieved by varying the quantity of coconut oil. The nanoparticles have been characterized by UV-Visible, Transmission Electron Microscopy and X-ray Diffraction. The chemical interaction of capping agents with metal nanoparticles is manifested using Fourier Transform Infrared Spectroscopy. The stable and crystalline nanoparticles obtained using this simple method show remarkable size-dependent catalytic activity in the reduction of the cationic dye methylene blue (MB) to leuco methylene blue (LMB). The first order rate constants calculated uphold the size dependent catalytic activity of the synthesized nanoparticles.

Altering the axial light gradient affects photomorphogenesis in emerging seedlings of Zea mays L

NASA Technical Reports Server (NTRS)

Parks, B. M.; Poff, K. L.

1986-01-01

The axial (longitudinal) red light gradient (632 nanometers) of 4 day old dark-grown maize seedlings is increased by staining the peripheral cells of the coleoptile. The magnitude of increase in the light gradient is dependent solely on the light-absorbing qualities of the stain used. Metanil yellow has no effect on the axial red-light gradient, while methylene blue causes a large increase in this light gradient. These stains did not affect growth in darkness or the sensitivity of mesocotyl elongation to red light. However, mesocotyl elongation was altered for the dark-grown seedlings stained with methylene blue when these seedlings were transplanted, covered with soil, and permitted to emerge under natural lighting conditions. These observations are consistent with the idea that there is a single perceptive site below the coleoptilar node, and suggest that this perceptive site gives the actinic light which has traveled downward through the length of the shoot from an entry point in the plant tip region.

Breakdown of methylene blue and methyl orange by pulsed corona discharge

NASA Astrophysics Data System (ADS)

Grabowski, L. R.; van Veldhuizen, E. M.; Pemen, A. J. M.; Rutgers, W. R.

2007-05-01

The recently developed corona above water technique is applied to water containing 10 mg l-1 methylene blue (MB) or methyl orange (MO). The corona discharge pulses are created with a spark gap switched capacitor followed by a transmission line transformer. The pulse amplitude is 40 kV; its duration is 50 ns. At a pulse repetition rate of 10 Hz this leads to an average power of 0.6 W into the discharge. MB and MO are completely decolourized in ~20 min. This corresponds to a yield of ~4.5 gr kW-1h-1, which is much higher than obtained with other discharge techniques or sonoluminescence. The high yield is reflected in the observed temperature increase of only ~1 K. Tests with additional chemicals show that the initial speed of the conversion can be influenced but the total time required for total decolourization is constant. Further, it follows that the main oxidation path of the dyes is by direct ozone attack and the conversion products are strong acids.

Removal of methyl orange and methylene blue dyes from aqueous solution using lala clam (Orbicularia orbiculata) shell

NASA Astrophysics Data System (ADS)

Eljiedi, Arwa Alseddig Ahmed; Kamari, Azlan

2017-05-01

Textile effluents are considered as potential sources of water pollution because they contain toxic dyes. In the present study, lala clam shell was used as an alternative low-cost adsorbent for the removal of two harmful dyes, namely methyl orange (MO) and methylene blue (MB) from aqueous solution. Batch adsorption studies were carried out by varying experimental parameters such as solution pH, initial concentration and adsorbent dosage. The optimum pH values for MO and MB removal were pH 2.0 and pH 8.0, respectively. At an initial MO and MB concentration of 20 mg/L, the maximum removal percentage of MO and MB were 18.9 % and 81.3 %, respectively. The adsorption equilibrium data were correlated with both Langmuir and Freundlich isotherm models. The biomass adsorbent was characterised using Field Emission Scanning Electron Microscope (FESEM) and Fourier Transform Infrared Spectrometer (FTIR). Results from this study suggest that lala clam shell, a fishery waste, can be beneficial for water treatment.

Photocatalytic activity enhancement of anatase-graphene nanocomposite for methylene removal: Degradation and kinetics.

PubMed

Rezaei, Mostafa; Salem, Shiva

2016-10-05

In the present research, the TiO2-graphene nanocomposite was synthesized by an eco-friendly method. The blackberry juice was introduced to graphene oxide (GO) as a reducing agent to produce the graphene nano-sheets. The nanocomposite of anatase-graphene was developed as a photocatalyst for the degradation of methylene blue, owing to the larger specific surface area and synergistic effect of reduced graphene oxide (RGO). The UV spectroscopy measurements showed that the prepared nanocomposite exhibited an excellent photocatalytic activity toward the methylene blue degradation. The rate of electron transfer of redox sheets is much higher than that observed on GO, indicating the applicability of proposed method for the production of anatase-RGO nanocomposite for treatment of water contaminated by cationic dye. The prepared materials were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller surface area measurement, scanning electron microscopy and transmission electron microscopy. A facile and rapid route was applied for the uniform deposition of anatase nanoparticles on the sheets. The resulting nanocomposite contained nanoparticles with a mean diameter of 10nm. A mechanism for the photocatalytic activity of nanocomposite was suggested and the degradation reaction obeyed the second-order kinetics. It was concluded that the degradation kinetics is changed due to the reduction of GO in the presence of blackberry juice. Copyright © 2016 Elsevier B.V. All rights reserved.

Holographic interferometry imaging monitoring of photodynamic (PDT) reactions in gelatin biophantom

NASA Astrophysics Data System (ADS)

Davidenko, N.; Mahdi, H.; Zheng, X.; Davidenko, I.; Pavlov, V.; Kuranda, N.; Chuprina, N.; Studzinsky, S.; Pandya, A.; Karia, H.; Tajouri, S.; Dervenis, M.; Gergely, C.; Douplik, A.

2018-01-01

Heat and photochemical reactions with human hemoglobin and photosensitizer were monitored by holography interference method in gelatin phantom. The method has successfully facilitated monitoring the reactions as a highresolution refraction index mapping in real time video regime. Methylene Blue was exploited as a photosensitizer.

Suitability of the methylene blue test for determination of cation exchange capacity of clay minerals related to ammonium acetate method

NASA Astrophysics Data System (ADS)

Milošević, Maja; Logar, Mihovil; Dojčinović, Biljana; Erić, Suzana

2015-04-01

Cation exchange capacity (CEC) represents one of the most important parameters of clay minerals which reflects their ability to exchange cations with liquid phases in near contact. Measurement of CEC is used for characterizing sample plasticity, adsorbing and swelling properties which later define their usage in industrial purposes. Several methods have been developed over the years for determination of layer charge, charge density, charge distribution, etc. and have been published in numerous papers (Czimerova et al., 2006; Yukselen and Kaya, 2008). The main goal of present study is comparison of suitability of more recent method - methylene blue test in regard to older method - ammonium acetate for determination of CEC. For this study, we selected one montmorillonite clay (Bogovina, Serbia) and two mainly kaolinite clays (Miličinica, Serbia). Chemicals used for CEC determinations were solution of methylene blue (MB)(14*10-6M/ml) and ammonium acetate (AA) solution (1M). The obtained results are showing generally lower values in case of MB method. The main difference is due to molecular aggregation of MB on the clay surface. AA method is highly sensitive to the presence of CaO. Release of Ca ion from the sample into the solution can limit the saturation of exchange sites by the ammonium ion. This is clearly visible in case of montmorillonite clay. Fe2+ and Mg ions are difficult to move by the ammonium ion because of their ion radius, but in case of MB molecule there is no such restriction in removing them from the exchange sites. MB solution, even in a low concentration (2*10-6M/ml), is showing preferable results in moving the ions from their positions which is already visible after adding a small quantity of solution (25cm3). Both MB-titration and MB-spot test yield similar results and are much simpler methods than AA and they also give other information such as specific surface area (external and internal) whereas AA method only provides information about cations in exchangeable positions. Both methods, methylene blue test and ammonium acetate method, have advantages and disadvantages and differ in their requirements for the sample preparations but in general method selection is depending on the specific application of the given sample. References: - Yukselen, Y. and Kaya, A., Engineering Geology 102 (2008) 38-45 - Czimerova, A., Bujdak, J. and Dohrmann, R., Applied Clay Science 34 (2006) 2-13

In vivo photoacoustic and ultrasonic mapping of rat sentinel lymph nodes with a modified commercial ultrasound imaging system

NASA Astrophysics Data System (ADS)

Erpelding, Todd N.; Kim, Chulhong; Pramanik, Manojit; Guo, Zijian; Dean, John; Jankovic, Ladislav; Maslov, Konstantin; Wang, Lihong V.

2010-02-01

Sentinel lymph node biopsy (SLNB) has become the standard method for axillary staging in breast cancer patients, relying on invasive identification of sentinel lymph nodes (SLNs) following injection of blue dye and radioactive tracers. While SLNB achieves a low false negative rate (5-10%), it is an invasive procedure requiring ionizing radiation. As an alternative to SLNB, ultrasound-guided fine needle aspiration biopsy has been tested clinically. However, ultrasound alone is unable to accurately identify which lymph nodes are sentinel. Therefore, a non-ionizing and noninvasive detection method for accurate SLN mapping is needed. In this study, we successfully imaged methylene blue dye accumulation in vivo in rat axillary lymph nodes using a Phillips iU22 ultrasound imaging system adapted for photoacoustic imaging with an Nd:YAG pumped, tunable dye laser. Photoacoustic images of rat SLNs clearly identify methylene blue dye accumulation within minutes following intradermal dye injection and co-registered photoacoustic/ultrasound images illustrate lymph node position relative to surrounding anatomy. To investigate clinical translation, the imaging depth was extended up to 2.5 cm by adding chicken breast tissue on top of the rat skin surface. These results raise confidence that photoacoustic imaging can be used clinically for accurate, noninvasive SLN mapping.

Textile dyes removal from aqueous solution using Opuntia ficus-indica fruit waste as adsorbent and its characterization.

PubMed

Peláez-Cid, A A; Velázquez-Ugalde, I; Herrera-González, A M; García-Serrano, J

2013-11-30

For this research, three different adsorbents, one untreated and two chemically activated, were prepared from Opuntia ficus-indica fruit waste. By the construction of adsorption isotherms, its adsorption capabilities and the viability of its use in the removal of textile basic and direct type dyes were determined. It was found that the adsorbent with the most adsorption capacity for basic dyes was the one activated with NaClO, and, for direct dyes, it was the one activated with NaOH. Langmuir and Freundlich equations isotherms were applied for the analysis of the experimental data. It was found that the Freundlich model best described the adsorption behavior. The adsorption capacity was improved when the pH of the dye solution had an acid value. The specific surface area of the adsorbents was calculated by means of methylene blue adsorption at 298 K to stay within a range between 348 and 643 m(2) g(-1). The FTIR spectroscopic characterization technique, the SEM, the point of zero charge, and the elemental analysis show the chemical and physical characteristics of the studied adsorbents, which confirm the adsorption results obtained. Copyright © 2013 Elsevier Ltd. All rights reserved.

Kinetic and calorimetric study of the adsorption of dyes on mesoporous activated carbon prepared from coconut coir dust.

PubMed

Macedo, Jeremias de Souza; da Costa Júnior, Nivan Bezerra; Almeida, Luis Eduardo; Vieira, Eunice Fragoso da Silva; Cestari, Antonio Reinaldo; Gimenez, Iara de Fátima; Villarreal Carreño, Neftali Lênin; Barreto, Ledjane Silva

2006-06-15

Mesoporous activated carbon has been prepared from coconut coir dust as support for adsorption of some model dye molecules from aqueous solutions. The methylene blue (MB) and remazol yellow (RY) molecules were chosen for study of the adsorption capacity of cationic and anionic dyes onto prepared activated carbon. The adsorption kinetics was studied with the Lagergren first- and pseudo-second-order kinetic models as well as the intraparticle diffusion model. The results for both dyes suggested a multimechanism sorption process. The adsorption mechanisms in the systems dyes/AC follow pseudo-second-order kinetics with a significant contribution of intraparticle diffusion. The samples simultaneously present acidic and basic sites able to act as anchoring sites for basic and acidic dyes, respectively. Calorimetric studies reveal that dyes/AC interaction forces are correlated with the pH of the solution, which can be related to the charge distribution on the AC surface. These AC samples also exhibited very short equilibrium times for the adsorption of both dyes, which is an economically favorable requisite for the activated carbon described in this work, in addition to the local abundance of the raw material.

Novel Claycunbic to Eliminate Micropollutants and Vibrio fischeri from Water

EPA Science Inventory

Montmorillonite clay (K10) was used as a precursor for the synthesis of a catalytic adsorbent, Claycunbic (Bi/Cu-pillared K10), which was characterized by SEM (EDS), TEM, XRD, BET, TGA and XPS analysis. The catalytic adsorption of cationic dye methylene blue (MB), anionic dye met...

Understanding wood chemistry changes during biopulping

Treesearch

Chris Hunt; William Kenealy; Carl Houtman

2003-01-01

Biopulping is the process of pretreating chips with fungus before mechanical pulping, resulting in significant energy savings and sheet strength improvements. This work presents sugar analysis, methylene blue adsorption, and titration data suggesting an increase in acid group content in wood is common with biopulping treatment. Some discussion of possible mechanisms of...

Low-intensity LED (625 and 405 nm) and laser (805 nm) killing of Propionibacterium acnes and Staphylococcus epidermidis

NASA Astrophysics Data System (ADS)

Tuchina, Elena S.; Tuchin, Valery V.

2009-02-01

In the present work we have investigated in vitro sensitivity of microorganisms P. acnes and S. epidermidis to action of red (625 nm and 405 nm) and infrared (805 nm) radiations in combination with photosensitizes Methylene Blue and Indocyanine Green.

New Electrorelease Systems Based on Microporous Membranes

DTIC Science & Technology

1990-08-02

correspondence (6) we demonstrated the validity of the concept by showing that insulin and vitamin B-12 can be electroreleased from a composite membrane...applied to the membrane. The dye reservoir contained an aqueous solution of either methylene blue dye (Aldrich), K3 Fe(CN)6 (Baker), or bovine insulin

Changes In Arterial Hemoglobin Oxygen Saturation During Transport From the Operating Room to the Postanesthesia Care Unit In Healthy Patients Breathing Room Air

DTIC Science & Technology

1998-12-16

motion artifact, electrical noise from the electrocautery, intravenous dyes such as methylene blue and indocyanine green, carboxyhemoglobin and... carboxyhemoglobin because the oximeter fails to distinguish between oxyhemoglobin and carboxyhemoglobin (Patel, Norden, & Hannallah, 1988) . Thus

SUBNANOMOLAR DETECTION OF ACID-LABILE SULFIDES BY THE CLASSICAL METHYLENE BLUE METHOD COUPLED TO HPLC. (R825395)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Porcine Intestinal Mast Cells. Evaluation of Different Fixatives for Histochemical Staining Techniques Considering Tissue Shrinkage

PubMed Central

Rieger, J.; Twardziok, S.; Huenigen, H.; Hirschberg, R.M.; Plendl, J.

2013-01-01

Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkagedifferences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different fixation techniques can only be compared if the respective studyimmanent shrinkage factor has been determined and quantification results are adjusted accordingly. PMID:24085270

SERS detection of indirect viral DNA capture using colloidal gold and methylene blue as a Raman label

USDA-ARS?s Scientific Manuscript database

An indirect capture model assay using colloidal Au nanoparticles is demonstrated for surface enhanced Raman scattering (SERS) spectroscopy detection of DNA. The sequence targeted for capture is derived from the West Nile Virus (WNV) RNA genome and was selected on the basis of exhibiting minimal seco...

Biodegradation of Methylene Blue Dye by Sequential Treatment Using Anaerobic Hybrid Reactor and Submerged Aerobic Fixed Film Bioreactor

NASA Astrophysics Data System (ADS)

Farooqi, Izharul H.; Basheer, Farrukh; Tiwari, Pradeepika

2017-12-01

Laboratory scale experiments were carried out to access the feasibility of sequential anaerobic/aerobic biological treatment for the biodegradation of Methylene Blue (MB) dye. Anaerobic studies were performed using anaerobic hybrid reactor (consisting of UASB and Anaerobic filter) whereas submerged aerobic fixed film reactor was used as aerobic reactor. Degradation of MB dye was attempted using neutralized acetic acid (1000 mg/L) as co-substrate. MB dye concentration was stepwise increased from 10 to 70 mg/L after reaching steady state in each dye concentration. Such a gradual increase in the dye concentration helps in the proper acclimatization of the sludge to dyes thereby avoiding the possible inhibitory effects to biological activities at high dye concentrations. The overall treatment efficiency of MB through sequential anaerobic-aerobic reactor operation was 90% at maximum attempted dye concentration of 70 mg/L. The effluent from anaerobic reactor was analysed for intermediate biodegradation products through HPLC. It was observed that catechol, quinone, amino pyrine, 1,4 diamino benzene were present. However they were absent in final effluent.

Engineering birnessite-type MnO2 nanosheets on fiberglass for pH-dependent degradation of methylene blue

NASA Astrophysics Data System (ADS)

Xin Zhang, Yu; Long Guo, Xiao; Huang, Ming; Dong Hao, Xiao; Yuan, Yuan; Hua, Chao

2015-08-01

We construct hierarchical MnO2 nanosheets @ fiberglass nanostructures via one-pot hydrothermal method without any surfactants. The morphology and structure of MnO2-modified fiberglass composites are examined by focus ion beam scanning electron microscopy (FIB/SEM), X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The birnessite-type MnO2 nanosheets are observed to grow vertically on the surface of fiberglass. Furthermore, the birnessite-type MnO2-fiberglass composites exhibit good ability for degradation of methylene blue (MB) in different pH levels. In neutral solution (pH 6.5-7.0), it achieves a high removal rate of 96.1% (2 h, at 60 °C) in the presence of H2O2; and in acidic environment (pH 1.5), 96.8% of MB solution (20 mg/L, 100 mL) is decomposed by oxidation within only 5 min. In principles, the rational design of MnO2 nanosheets-decorated fiberglass architectures demonstrated the suitability of the low-cost MnO2-modified fiberglass nanostructure for water treatment.

Titania modified activated carbon prepared from sugarcane bagasse: adsorption and photocatalytic degradation of methylene blue under visible light irradiation.

PubMed

El-Salamony, R A; Amdeha, E; Ghoneim, S A; Badawy, N A; Salem, K M; Al-Sabagh, A M

2017-12-01

Activated carbon (AC), prepared from sugarcane bagasse waste through a low-temperature chemical carbonization treatment, was used as a support for nano-TiO 2 . TiO 2 supported on AC (xTiO 2 -AC) catalysts (x = 10, 20, 50, and 70 wt.%) were prepared through a mechano-mixing method. The photocatalysts were characterized by Raman, X-ray diffraction analysis, FTIR, S BET , field emission scanning electron microscope, and optical technique. The adsorption and photo-activity of the prepared catalysts (xTiO 2 -AC) were evaluated using methylene blue (MB) dye. The photocatalytic degradation of MB was evaluated under UVC irradiation and visible light. The degradation percentage of the 100 ppm MB at neutral pH using 20TiO 2 -AC reaches 96 and 91 after 180 min under visible light and UV irradiation, respectively. In other words, these catalysts are more active under visible light than under UV light irradiation, opening the possibility of using solar light for this application.

Photodegradation of methylene blue with PVA/PVP blend under UV light irradiation

NASA Astrophysics Data System (ADS)

Zidan, H. M.; El-Ghamaz, N. A.; Abdelghany, A. M.; Waly, A. L.

2018-06-01

Homogenous films of PVA/PVP blend (1:1) doped with different levels of methylene blue dye (MB) were prepared using the casting technique. The absorption spectra of doped PVA/PVP blend showed two absorption peaks due to the chromophor groups of MB while the pure PVA/PVP blend does not. The UV irradiation causes photodegradation of MB dye. The recovery of photodegraded MB is observed after keeping the sample 3 h in atmospheric air. The value of the optical energy gap (Eg) decreases with increasing the doping levels with MB. The spectral distribution of absorption index (k) and refractive index (n) are determined from the reflection and transmission spectra in the spectral range 200-2500 nm. The dependence of both n and k on wavelength of the incident light and the wt% content of MB in PVA/PVP blend is discussed. A normal dispersion observed at wavelength λ > 370 nm for pure PVA/PVP blend and λ > 800 nm for MB doped samples. The obtained results suggest the possible use of the studied system in many applications.

[Effects of the adsorbent CAA for hemopurification on normal components of human plasma in removing methylene blue].

PubMed

Ma, Yu; Xia, Yun; Yang, Xiaolan; Yu, Ming'an

2003-06-01

Virus inactivation of plasma can be achieved by phototreatment with methylene blue (MB). Subsequently, elimination of MB may reduce the adverse effects of MB. This study examined the effects of adsorbing MB with the use of cross-linked agar bead entrapped attapulgite clay (CAA) on normal ingredients in MB-treated plasma units. The biomedical characteristics of CAA were assessed by determination of partial biochemical indexes, coagulation potency and some cationic concentration in a control sample and the MB-treated plasma eluted from CAA column. The biochemistry indexes or K+, Na+ in plasma were almost unaltered before and after CAA adsorption. In contrast, the concentrations of CA2+ and Mg2+ increased and the blood ammonium decreased obviously. The activated partial thromboplastin time (APTT) was prolonged from 42 s to 53 s, and prothrombin time (PT) from 13 s to 14 s. The result indicates that CAA as an adsorbent for hemopurification retains the most important characters of human plasma. CAA can be useful for the elimination of MB in MB-treated plasma and does not bring on harmful alteration in clinical significance.

Mathematical modelling of metabolic pathways affected by an enzyme deficiency. Energy and redox metabolism of glucose-6-phosphate-dehydrogenase-deficient erythrocytes.

PubMed

Schuster, R; Jacobasch, G; Holzhütter, H G

1989-07-01

The effects of various forms of glucose-6-phosphate dehydrogenase deficiency on erythrocyte metabolism have been studied on the basis of a complex mathematical model which comprises the main pathways of this cell: glycolysis, pentose pathway, reactions of the glutathione and adenine nucleotide metabolism. The calculated flux rates through the oxidative pentose pathway with and without methylene blue are in good accord with experimental results. The degree of deficiency as predicted by the model on the basis of calculated upper oxidative load boundaries, as well as of maximal methylene blue stimulation, correlates with the individual clinical manifestation of the metabolic disease. Therefore, the model allows one to judge the degree of metabolic disorder in the presence of glucose-6-phosphate dehydrogenase enzymopathies if the kinetic properties of the defect enzyme are known. Experimentally accessible parameters for an assessment of the oxidative load capacity of cells in vivo are proposed. It is pointed out that the threshold of tolerance as to energetic load is drastically reduced in the case of severe glucose-6-phosphate dehydrogenase deficiency.

Removal of anionic and cationic dyes with bioadsorbent oxidized chitosans.

PubMed

León, Orietta; Muñoz-Bonilla, Alexandra; Soto, Diana; Pérez, Daniela; Rangel, Medarda; Colina, Marinela; Fernández-García, Marta

2018-08-15

Different oxidized chitosans were prepared following various approaches, by thermo-acid oxidation or by using KMnO 4 /NaHSO 3 , (NH 4 ) 2 S 2 O 8 /NaHSO 3 and K 2 Cr 2 O 7 /NaHSO 3 redox pairs added sequentially or simultaneously. All these reactions pursue the formation of carboxylic groups which enhance their capability to remove model cationic and anionic dyes such as methylene blue and methyl orange, respectively. The resulting oxidized chitosans were structurally and thermally characterized by elemental analysis, infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy and thermogravimetry. The swelling capacity of these hydrogels was also determined as well as the remediation ability of dyes in different conditions. The results showed that the adsorption of methylene blue followed a pseudo second-order kinetics model, while the adsorption behavior was in agreement with the Langmuir isotherm model. Remarkably, the oxidized chitosans showed removal ability for both dyes cationic and anionic, which of great importance for application of these materials as versatile bioadsorbents. Copyright © 2018 Elsevier Ltd. All rights reserved.

NIR-light-induced surface-enhanced Raman scattering for detection and photothermal/photodynamic therapy of cancer cells using methylene blue-embedded gold nanorod@SiO2 nanocomposites

PubMed Central

Seo, Sun-Hwa; Kim, Bo-Mi; Joe, Ara; Han, Hyo-Won; Chen, Xiaoyuan; Cheng, Zhen; Jang, Eue-Soon

2015-01-01

Methylene blue-loaded gold nanorod@SiO2 (MB-GNR@SiO2) core@shell nanoparticles are synthesized for use in cancer imaging and photothermal/photodynamic dual therapy. For the preparation of GNR@SiO2 nanoparticles, we found that the silica coating rate of hexadecylcetyltrimethylammonium bromide (CTAB)-capped GNRs is much slower than that of PEGylated GNRs due to the densely coated CTAB bilayer. Encapsulated MB molecules have both monomer and dimer forms that result in an increase in the photosensitizing effect through different photochemical pathways. As a consequence of the excellent plasmonic properties of GNRs at near-infrared (NIR) light, the embedded MB molecules showed NIR light-induced SERS performance with a Raman enhancement factor of 3.0 × 1010, which is enough for the detection of a single cancer cell. Moreover, the MB-GNR@SiO2 nanoparticles exhibit a synergistic effect of photodynamic and photothermal therapies of cancer under single-wavelength NIR laser irradiation. PMID:24424205

Heterogeneous photodegradation of methylene blue with iron and tea or coffee polyphenols in aqueous solutions.

PubMed

Morikawa, Claudio Kendi; Shinohara, Makoto

2016-01-01

Recently, we developed two new Fenton catalysts using iron (Fe) and spent tea leaves or coffee grounds as raw material. In this study, Fe-to-tea or Fe-to-coffee polyphenol complexes were successfully tested as heterogeneous photo-Fenton catalysts. The photodegradation efficiency of methylene blue solutions with Fe-to-polyphenol complexes was higher than that of homogeneous iron salts in the photo-Fenton process. Furthermore, the tested Fe-to-polyphenol complexes could be reused by simply adding H2O2 to the solutions. After three sequential additions of H2O2, the conventional catalysts FeCl2·4H2O and FeCl3 removed only 16.6% and 53.6% of the dye, while the catalysts made using spent coffee grounds and tea leaves removed 94.4% and 96.0% of the dye, respectively. These results showed that the complexes formed between Fe and chlorogenic acid, caffeic acid, gallic acid and catechin, which are the main polyphenols in tea and coffee, can be used to improve the photo-Fenton process.

Application of response surface methodology (RSM) for the removal of methylene blue dye from water by nano zero-valent iron (NZVI).

PubMed

Khosravi, Morteza; Arabi, Simin

In this study, iron zero-valent nanoparticles were synthesized, characterized and studied for removal of methylene blue dye in water solution. The reactions were mathematically described as the function of parameters such as nano zero-valent iron (NZVI) dose, pH, contact time and initial dye concentration, and were modeled by the use of response surface methodology. These experiments were carried out as a central composite design consisting of 30 experiments determined by the 2(4) full factorial designs with eight axial points and six center points. The results revealed that the optimal conditions for dye removal were NZVI dose 0.1-0.9 g/L, pH 3-11, contact time 20-100 s, and initial dye concentration 10-50 mg/L, respectively. Under these optimal values of process parameters, the dye removal efficiency of 92.87% was observed, which very close to the experimental value (92.21%) in batch experiment. In the optimization, R(2) and R(2)adj correlation coefficients for the model were evaluated as 0.96 and 0.93, respectively.

Synthesis of ZnO/CuO and TiO{sub 2}/CuO nanocomposites for light and ultrasound assisted degradation of a textile dye in aqueous solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muzakki, Afifah; Shabrany, Hesni; Saleh, Rosari, E-mail: rosari.saleh@gmail.com, E-mail: rosari.saleh@ui.ac.id

2016-04-19

ZnO/CuO and TiO2/CuO nanocomposites with different Zn/Cu and Ti/Cu ratios were prepared using sol-gel method. The obtained composite samples were used as catalyst. Methylene blue was used as a model of textile dye to evaluate their photocatalytic, sonocatalytic and photosonocatalytic activities. X-ray diffraction and energy dispersive X- ray analysis confirmed that only monoclinic CuO and hexagonal wurtzite ZnO structures are present in ZnO/CuO nanocomposites, while in TiO2/CuO nanocomposites monoclinic CuO and anatase TiO2 structures were observed. The degradation of methylene blue indicated that the incorporation of CuO in ZnO/CuO and TiO2/CuO nanocomposites exhibited an appreciable higher photocatalytic activity, which wasmore » mainly attributed to the extended photoresponding range and more light energy could be utilized than pure ZnO and TiO2.« less

NIR-light-induced surface-enhanced Raman scattering for detection and photothermal/photodynamic therapy of cancer cells using methylene blue-embedded gold nanorod@SiO2 nanocomposites.

PubMed

Seo, Sun-Hwa; Kim, Bo-Mi; Joe, Ara; Han, Hyo-Won; Chen, Xiaoyuan; Cheng, Zhen; Jang, Eue-Soon

2014-03-01

Methylene blue-loaded gold nanorod@SiO2 (MB-GNR@SiO2) core@shell nanoparticles are synthesized for use in cancer imaging and photothermal/photodynamic dual therapy. For the preparation of GNR@SiO2 nanoparticles, we found that the silica coating rate of hexadecylcetyltrimethylammonium bromide (CTAB)-capped GNRs is much slower than that of PEGylated GNRs due to the densely coated CTAB bilayer. Encapsulated MB molecules have both monomer and dimer forms that result in an increase in the photosensitizing effect through different photochemical pathways. As a consequence of the excellent plasmonic properties of GNRs at near-infrared (NIR) light, the embedded MB molecules showed NIR light-induced SERS performance with a Raman enhancement factor of 3.0 × 10(10), which is enough for the detection of a single cancer cell. Moreover, the MB-GNR@SiO2 nanoparticles exhibit a synergistic effect of photodynamic and photothermal therapies of cancer under single-wavelength NIR laser irradiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polydopamine-based functional composite particles for tumor cell targeting and dual-mode cellular imaging.

PubMed

Zhou, Yalei; Zhou, Jie; Wang, Feng; Yang, Haifeng

2018-05-01

Particles which bear tumor cell targeting and multimode imaging capabilities are promising in tumor diagnosis and cancer therapy. A simple and versatile method to fabricate gold/polydopamine-Methylene Blue@Bovine Serum Albumin-glutaraldehyde-Transferrin composite particles (Au/PDA-MB@BSA-GA-Tf NPs) for tumor cell targeting and fluorescence (FL) / surface-enhanced Raman scattering (SERS) dual-modal imaging were reported in this work. Polydopamine (PDA) spheres played an important role in gold ion reduction, gold nanoparticle (Au NPs) binding and methylene blue (MB) adsorption, MB were employed as both fluorescence label and Raman reporter. In addition, glutaraldehyde (GA) crosslinked bovine serum albumin (BSA) in the outer layer of Au/PDA-MB nanoparticles can prevent MB from dissociation and leakage. The composite nanoparticles were further conjugated with transferrin (Tf) to target transferrin receptor (TfR)-overexpressed cancer cells. The targeting ability as well as the intracellular location of the probe was investigated through SERS mapping and fluorescence imaging. Their excellent biocompatibility was demonstrated by low cytotoxicity against breast cancer cell (4T1 cell). Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation of modified semi-coke by microwave heating and adsorption kinetics of methylene blue.

PubMed

Wang, Xin; Peng, Jin-Hui; Duan, Xin-Hui; Srinivasakannan, Chandrasekar

2013-01-01

Preparation of modified semi-coke has been achieved, using phosphoric acid as the modifying agent, by microwave heating from virgin semi-coke. Process optimization using a Central Composite Design (CCD) design of Response Surface Methodology (RSM) technique for the preparation of modifies semi-coke is presented in this paper. The optimum conditions for producing modified semi-coke were: concentration of phosphoric acid 2.04, heating time 20 minutes and temperature 587 degrees C, with the optimum iodine of 862 mg/g and yield of 47.48%. The textural characteristics of modified semi-coke were analyzed using scanning electron microscopy (SEM) and nitrogen adsorption isotherm. The BET surface area of modified semi-coke was estimated to be 989.60 m2/g, with the pore volume of 0.74 cm3/g and a pore diameter of 3.009 nm, with micro-pore volume contributing to 62.44%. The Methylene Blue monolayer adsorption capacity was found to be mg/g at K. The adsorption capacity of the modified semi-coke highlights its suitability for liquid phase adsorption application with a potential usage in waste water treatment.

Inactivation of Ebola virus and Middle East respiratory syndrome coronavirus in platelet concentrates and plasma by ultraviolet C light and methylene blue plus visible light, respectively.

PubMed

Eickmann, Markus; Gravemann, Ute; Handke, Wiebke; Tolksdorf, Frank; Reichenberg, Stefan; Müller, Thomas H; Seltsam, Axel

2018-05-06

Ebola virus (EBOV) and Middle East respiratory syndrome coronavirus (MERS-CoV) have been identified as potential threats to blood safety. This study investigated the efficacy of the THERAFLEX UV-Platelets and THERAFLEX MB-Plasma pathogen inactivation systems to inactivate EBOV and MERS-CoV in platelet concentrates (PCs) and plasma, respectively. PCs and plasma were spiked with high titers of cell culture-derived EBOV and MERS-CoV, treated with various light doses of ultraviolet C (UVC; THERAFLEX UV-Platelets) or methylene blue (MB) plus visible light (MB/light; THERAFLEX MB-Plasma), and assessed for residual viral infectivity. UVC reduced EBOV (≥4.5 log) and MERS-CoV (≥3.7 log) infectivity in PCs to the limit of detection, and MB/light decreased EBOV (≥4.6 log) and MERS-CoV (≥3.3 log) titers in plasma to nondetectable levels. Both THERAFLEX UV-Platelets (UVC) and THERAFLEX MB-Plasma (MB/light) effectively reduce EBOV and MERS-CoV infectivity in platelets and plasma, respectively. © 2018 AABB.

Fabrication of cellulose nanocrystal from Carex meyeriana Kunth and its application in the adsorption of methylene blue.

PubMed

Yang, Xue; Liu, Hui; Han, Fuyi; Jiang, Shuai; Liu, Lifang; Xia, Zhaopeng

2017-11-01

Cellulose nanocrystal (CNC) was extracted from Carex meyeriana Kunth (CMK) by a combination of TEMPO oxidation and mechanical homogenization method, and used to remove methylene blue (MB) from aqueous solution. After alkali-oxygen treatment, the aqueous biphasic system (polyethylene glycol/inorganic salt) was applied to further remove lignin from CMK. The characteriazation of CNC, and the effects of H 2 O 2 dosage, CNC dosage, adsorption time, and initial MB concentration on the MB removal capacity of CNC were investigated. The results showed that the removal percentage of MB by CNC was raised with the increase of H 2 O 2 and CNC dosage. The adsorption kinetics of prepared CNC followed the pseudo-second-order model, and the adsorption isotherms fitted well to the Langmuir model with a calculated maximum adsoption capacity of 217.4mg/g, which was higher than those of CNC extracted by acid hydrolysis method, indicating CNC extracted from CMK had promising potentials in the field of MB adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

One-Pot Route towards Active TiO2 Doped Hierarchically Porous Cellulose: Highly Efficient Photocatalysts for Methylene Blue Degradation

PubMed Central

Sun, Xiaoxia; Wang, Kunpeng; Shu, Yu; Zou, Fangdong; Zhang, Boxing; Sun, Guangwu; Uyama, Hiroshi; Wang, Xinhou

2017-01-01

In this study, novel photocatalyst monolith materials were successfully fabricated by a non-solvent induced phase separation (NIPS) technique. By adding a certain amount of ethyl acetate (as non-solvent) into a cellulose/LiCl/N,N-dimethylacetamide (DMAc) solution, and successively adding titanium dioxide (TiO2) nanoparticles (NPs), cellulose/TiO2 composite monoliths with hierarchically porous structures were easily formed. The obtained composite monoliths possessed mesopores, and two kinds of macropores. Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), and Ultraviolet-visible Spectroscopy (UV-Vis) measurements were adopted to characterize the cellulose/TiO2 composite monolith. The cellulose/TiO2 composite monoliths showed high efficiency of photocatalytic activity in the decomposition of methylene blue dye, which was decomposed up to 99% within 60 min under UV light. Moreover, the composite monoliths could retain 90% of the photodegradation efficiency after 10 cycles. The novel NIPS technique has great potential for fabricating recyclable photocatalysts with highly efficiency. PMID:28772734

Solution Combustion Synthesis of Ni/NiO/ZnO Nanocomposites for Photodegradation of Methylene Blue Under Ultraviolet Irradiation

NASA Astrophysics Data System (ADS)

Biglari, Z.; Masoudpanah, S. M.; Alamolhoda, S.

2018-02-01

In this work, Ni/NiO/ZnO nanocomposites were synthesized by the one-pot solution combustion synthesis method. Phase evolution investigated by the x-ray diffraction method showed that the ZnO and NiO contents can be tuned by addition of a zinc precursor. The microstructure characterized by electron microscopy exhibited granular morphology with a particle size of 1.1 μm decreasing to 90 nm as a function of the amounts of ZnO and NiO phases. Specific surface area determined by N2 adsorption-desorption isotherms increased from 1.4 m2/g to 25.6 m2/g with the increase of oxide phases. However, the saturation magnetization decreased from 51.3 emu/g to 25.9 emu/g in the presence of antiferromagnetic NiO and nonmagnetic ZnO phases. Photodegradation of methylene blue under ultraviolet light exhibited the maximum efficiency in the sample containing 16.25 wt.% of ZnO and 21.25 wt.% of NiO, and may be due to the synergic effect between ZnO and NiO.

New Composites LnBDC@AC and CB[6]@AC: From Design toward Selective Adsorption of Methylene Blue or Methyl Orange

PubMed Central

Santos, Guilherme de C.; Barros, Amanda L.; de Oliveira, Carlos A. F.; da Luz, Leonis L.; da Silva, Fausthon F.; Demets, Grégoire J.-F.; Alves Júnior, Severino

2017-01-01

New porous composites LnBDC@AC (AC = Activated carbon, Ln = Eu and Gd and BDC = 1,4-benzenedicaboxylate) and CB[6]@AC (CB[6] = Cucurbit[6]uril) were obtained using hydrothermal route. The LnBDC and CB[B] are located inside the pore of the carbon materials as was observed in SEM-EDS, XRPD and FT-IR analysis. Porosimetry analysis showed values typically between AC and LnBDC material, with pore size and surface area, respectively, 29,56 Å and 353.98 m2g-1 for LnBDC@AC and 35,53 Å and 353.98 m2g-1 for CB[6]@AC. Both materials showed good absorptive capacity of metil orange (MO) and methylene blue (MB) with selectivity as a function of pH. For acid pH, both materials present selectivity by MB and alkaline pH for MO, with notable performance for CB[6]@AC. Additionally, europium luminescence was used as structural probe to investigate the coordination environment of Eu3+ ions in the EuBDC@AC composite after adsorption experiment. PMID:28107440

Magnetic and photocatalytic studies on Zn1-xMgxFe2O4 nanocolloids synthesized by solvothermal reflux method.

PubMed

Manohar, A; Krishnamoorthi, C

2017-12-01

Biocompatible magnetic semiconductor Zn 1-x Mg x Fe 2 O 4 (x=0, 0.1, 0.3, 0.5 & 0.7) nanoparticles of around 10nm diameter were synthesized by solvothermal reflux method. The method produces well separated and narrow size distributed nanoparticles. Crystal structure, morphology, particles surface properties, surfactant quantity, colloidal stability, magnetic properties and photocatalytic properties of the synthesized nanoparticles were studied. Different characterizations confirmed that all compounds were single crystals and superparamagnetic at room temperature. Saturation mass magnetization (M s =57.5emu/g) enhances with substituent Mg 2+ concentration due to promotion of mixed spinel (normal and inverse) structure. Photocatalytic activity of all synthesized magnetic semiconductor nanoparticles were studied through methylene blue degradation. The degradation of 98% methylene blue was observed on 60 min irradiation of light. It is observed that photocatalytic activity slightly enhances with substituent Mg 2+ concentration. The synthesized biocompatible magnetic semiconductor nanoparticles can be utilized as photocatalysts and could also be recycled and separated by applying an external magnetic field. Copyright © 2017 Elsevier B.V. All rights reserved.

The synthesis of Cu/Fe/Fe3O4 catalyst through the aqueous solution ball milling method assisted by high-frequency electromagnetic field

NASA Astrophysics Data System (ADS)

Yingzhe, Zhang; Yuxing, He; Qingdong, Qin; Fuchun, Wang; Wankun, Wang; Yongmei, Luo

2018-06-01

In this paper, nano-magnetic Cu/Fe/Fe3O4 catalyst was prepared by a new aqueous solution ball milling method assisted by high-frequency electromagnetic field at room temperature. The products were characterized by means of X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED), and vibrating sample magnetometer (VSM). Microwave induced catalytic degradation of methylene blue (MB) was carried out in the presence of Cu/Fe/Fe3O4. The concentration of methylene blue was determined by UV-Vis spectrophotometry. The solid catalyst showed high catalytic activity of degrade MB and considerable saturation magnetization, lower remanence and coercivity. It indicate that the catalyst can be effectively separated for reuse by simply applying an external magnetic field and it can greatly promote their potential industrial application to eliminate organic pollutants from waste-water. Finally, we found that it is the non-thermal effect of microwave that activated the catalytic activity of Cu/Fe/Fe3O4 to degrade MB.

FABRICATION AND PHOTOCATALYTIC PROPERTIES OF TiO2 NANOFILMS CO-DOPED WITH Fe3+ AND Bi3+ IONS

NASA Astrophysics Data System (ADS)

Gao, Qiongzhi; Liu, Xin; Liu, Wei; Liu, Fang; Fang, Yueping; Zhang, Shiying; Zhou, Wuyi

2016-12-01

In this work, the titanium dioxide (TiO2) nanofilms co-doped with Fe3+ and Bi3+ ions were successfully fabricated by the sol-gel method with dip-coating process. Methylene blue was used as the target degradation chemical to study the photocatalytic properties affected by different doping contents of Fe3+ and Bi3+ ions. The samples were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The results indicated that both pure TiO2 nanofilms and single-doped samples possessed the photocatalytic activity in degradation of methylene blue. However, when the nanofilms co-doped with Fe3+ and Bi3+ ions were fabricated at the molar ratio of 3:1 (Fe3+:Bi3+), they exhibited the best photocatalytic activity after the heat treatment at 500∘C for 2h. The wettability property test indicated that the TiO2 nanofilms co-doped with Fe3+ and Bi3+ ions in the molar ratio 3:1 owned an excellent hydrophilic property.

Heterogeneous photo-Fenton processes using graphite carbon coating hollow CuFe2O4 spheres for the degradation of methylene blue

NASA Astrophysics Data System (ADS)

Guo, Xiaojun; Wang, Kebai; Li, Dai; Qin, Jiabin

2017-10-01

The novel graphite carbon coating hollow CuFe2O4 spheres were fabricated through solvothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectra, etc. The catalytic performance of the graphite carbon coating hollow CuFe2O4 spheres was evaluated in photo-Fenton-like degradation of methylene blue (MB) using H2O2 as a green oxidant under light irradiation (λ > 400 nm). The results demonstrated that the hollow CuFe2O4 spheres with graphite carbon coating exhibited superior catalytic activity. In the preparation process of catalyst, the addition of glucose was very important to its catalytic performance. Photoresponse analysis of the typical samples proved that CuFe2O4@graphite carbon core-shell hollow spheres possessed excellent photocurrent response and lower electrochemical impedance. In addition, a possible mechanism for photocatalytic degradation of MB had been presumed. Moreover, after five regeneration cycles, the graphite carbon coating hollow CuFe2O4 spheres still exhibited better properties.

Surface modification of porous suspended ceramsite used for water treatment by activated carbon/Fe3O4 magnetic composites.

PubMed

Lu, Mang; Xia, Guang-Hua; Zhao, Xiao-Dong

2013-01-01

In this study, porous suspended ceramsite with a specific density close to that of water was prepared by high-temperature calcination using fly ash, feldspar, calcite, fired talc and kaolin as the raw materials. The ceramsite was modified by activated carbon/Fe3O4 magnetic composites. The optimum modification conditions determined by methylene blue adsorption experiment were: KOH/glucose ratio of 1.5:1, carbonization temperature of 400 degrees C, activation temperature of 850 degrees C, activation time of 1 h, and Fe3O4/KOH+glucose ratio of 1:10. The results demonstrated that the adsorption capacity of the modified ceramsite for methylene blue was significantly higher than that of the unmodified ones. The presence of the composites did not lead to significant decrease in the mechanical properties of the modified ceramsite. Moreover, the modified ceramsite showed good resistance towards acid and alkali. The modified ceramsite can be used as biocarrier and adsorbent for a wide range of contaminants in water and can subsequently be removed from the medium by a simple magnetic procedure.

Mesoporous activated carbon prepared from NaOH activation of rattan (Lacosperma secundiflorum) hydrochar for methylene blue removal.

PubMed

Islam, Md Azharul; Ahmed, M J; Khanday, W A; Asif, M; Hameed, B H

2017-04-01

Hydrothermal carbonization of biomass wastes presents a promising step in the production of cost-effective activated carbon. In the present work, mesoporous activated carbon (HAC) was prepared by the hydrothermal carbonization of rattan furniture wastes followed by NaOH activation. The textural and morphological characteristics, along with adsorption performance of prepared HAC toward methylene blue (MB) dye, were evaluated. The effects of common adsorption variables on performance resulted in a removal efficiency of 96% for the MB sample at initial concentration of 25mg/L, solution pH of 7, 30°C, and 8h. The Langmuir equation showed the best isotherm data correlation, with a maximum uptake of 359mg/g. The adsorbed amount versus time data was well fitted by a pseudo-second order kinetic model. The prepared HAC with a high surface area of 1135m 2 /g and an average pore size distribution of 35.5Å could be an efficient adsorbent for treatment of synthetic dyes in wastewaters. Copyright © 2017 Elsevier Inc. All rights reserved.

Nitrogen Doped Graphene Nickel Ferrite Magnetic Photocatalyst for the Visible Light Degradation of Methylene Blue.

PubMed

Singh, Rajinder; Ladol, Jigmet; Khajuria, Heena; Sheikh, Haq Nawaz

2017-01-01

A facile approach has been devised for the preparation of magnetic NiFe2O4 photocatalyst (NiFe2O4-NG) supported on nitrogen doped graphene (NG). The NiFe2O4-NG composite was synthesized by one step hydrothermal method. The nanocomposite catalyst was characterized by Powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-Vis) and Vibrating sample magnetometry (VSM). It is found that the combination of NiFe2O4 nanoparticles with nitrogen-doped graphene sheets converts NiFe2O4 into a good catalyst for methylene blue (MB) dye degradation by irradiation of visible light. The catalytic activity under visible light irradiation is assigned to extensive movement of photogenerated electron from NiFe2O4 to the conduction band of the reduced NG, effectively blocking direct recombination of electrons and holes. The NiFe2O4 nanoparticles alone have efficient magnetic property, so can be used for magnetic separation in the solution without additional magnetic support.

TiO₂ (rutile) embedded inulin--A versatile bio-nanocomposite for photocatalytic degradation of methylene blue.

PubMed

Jayanthi Kalaivani, G; Suja, S K

2016-06-05

Inulin, a water soluble carbohydrate polymer, was extracted from Allium sativum L. by hot water diffusion method. A novel bio-nanocomposite was prepared by embedding TiO2 (rutile) onto the inulin matrix. The extracted inulin and the prepared bio-nanocomposite were characterized using UV-vis, FT-IR, XRD, SEM, TEM and TGA techniques. The photocatalytic activity of the bio-nanocomposite for the degradation of methylene blue was studied under UV illumination in batch mode experiment and was found to be twice as high as that of pristine TiO2. The kapp for inulin-TiO2 (0.0449 min(-1)) was higher than that for TiO2 (0.0325 min(-1)) which may be due to the synergistic action of inulin and TiO2. The stabilization of photo excited electron suppressed the electron-hole pair recombination thereby inducing the electrons and the holes to participate in the photo reduction and oxidation processes, respectively and enhancing the photocatalytic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Complexing Methylene Blue with Phosphorus Dendrimers to Increase Photodynamic Activity.

PubMed

Dabrzalska, Monika; Janaszewska, Anna; Zablocka, Maria; Mignani, Serge; Majoral, Jean Pierre; Klajnert-Maculewicz, Barbara

2017-02-23

The efficiency of photodynamic therapy is limited mainly due to low selectivity, unfavorable biodistribution of photosensitizers, and long-lasting skin sensitivity to light. However, drug delivery systems based on nanoparticles may overcome the limitations mentioned above. Among others, dendrimers are particularly attractive as carriers, because of their globular architecture and high loading capacity. The goal of the study was to check whether an anionic phosphorus dendrimer is suitable as a carrier of a photosensitizer-methylene blue (MB). As a biological model, basal cell carcinoma cell lines were used. We checked the influence of the MB complexation on its singlet oxygen production ability using a commercial fluorescence probe. Next, cellular uptake, phototoxicity, reactive oxygen species (ROS) generation, and cell death were investigated. The MB-anionic dendrimer complex (MB-1an) was found to generate less singlet oxygen; however, the complex showed higher cellular uptake and phototoxicity against basal cell carcinoma cell lines, which was accompanied with enhanced ROS production. Owing to the obtained results, we conclude that the photodynamic activity of MB complexed with an anionic dendrimer is higher than free MB against basal cell carcinoma cell lines.

Synthesis of pore-variable mesoporous CdS and evaluation of its photocatalytic activity in degrading methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wei-Min, E-mail: chm_zhangwm@ujn.edu.cn; Jiang, Yao-Quan; Cao, Xiao-Yan

2013-10-15

Graphical abstract: - Highlights: • Self-templated synthesis of tubular CdS. • Cadmium complexes of aliphatic acids sustain the network of mesoporous structures. • Aliphatic acids affect the phase composition and particle size. • Pore size and volume vary with aliphatic acids having different hydrocarbonyl. - Abstract: In this study, mesoporous CdS polycrystallites have been synthesized using aliphatic acids of hexanoic acid, octanoic acid, and oleic acid as coordinating and capping agents, respectively. The fibrous Cd–fatty acid salts act as a template to form the tubular CdS. The organic species are found to be necessary for maintaining the network of mesoporousmore » CdS. The characterization results indicate that the shorter carbon chain length in aliphatic acids favors the wurtzite phase and particle size growth the specific surface area, pore diameter and pore volume show a monotonic raise with increasing carbon chain. The photocatalytic activities of mesoporous CdS tubes exhibit much higher efficiency than those of nanosized CdS powders in decolorizing methylene blue under simulated visible light.« less