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Hydroxylated polymethoxyflavones reduce the activity of pancreatic lipase, inhibit adipogenesis and enhance lipolysis in 3T3-L1 mouse embryonic fibroblast cells. Chem Biol Interact 2023; 379:110503. [PMID: 37084996 DOI: 10.1016/j.cbi.2023.110503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 04/23/2023]
Abstract
Hydroxylated polymethoxyflavones (HPMFs) have been shown to possess various anti-disease effects, including against obesity. This study investigates the anti-obesity effects of HPMFs in further detail, aiming to gain understanding of their mechanism of action in this context. The current study demonstrates that two HPMFs; 3'-hydroxy-5,7,4',5'-tetramethoxyflavone (3'OH-TetMF) and 4'-hydroxy-5,7,3',5'-tetramethoxyflavone (4'OH-TetMF) possess anti-obesity effects. They both significantly reduced pancreatic lipase activity in a competitive manner as demonstrated by molecular docking and kinetic studies. In cell studies, it was revealed that both of the HPMFs suppress differentiation of 3T3-L1 mouse embryonic fibroblast cells during the early stages of adipogenesis. They also reduced expression of key adipogenic and lipogenic marker genes, namely peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), adipocyte binding protein 2 (aP2), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBF 1). They also enhanced the expression of cell cycle genes, i.e., cyclin D1 (CCND1) and C-Myc, and reduced cyclin A2 expression. When further investigated, it was also observed that these HPMFs accelerate lipid breakdown (lipolysis) and enhance lipolytic gene expression. Moreover, they also reduced the secretion of proteins (adipokines), including pro-inflammatory cytokines, from mature adipocytes. Taken together, this study concludes that these HPMFs have anti-obesity effects, which are worthy of further investigation.
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Anti-pancreatic lipase and anti-adipogenic effects of 5, 7, 3',4',5' -pentamethoxy and 6, 2',4'-trimethoxy flavone - An In vitro study. Eur J Pharmacol 2022; 938:175445. [PMID: 36473593 DOI: 10.1016/j.ejphar.2022.175445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022]
Abstract
In this study, the anti-obesity effects of 5,7,3',4',5-pentamethoxyflavone (PMF) and 6,2',4'-trimethoxyflavone (TMF) were evaluated through two distinct mechanisms of action: inhibition of crude porcine pancreatic lipase (PL), and inhibition of adipogenesis in 3T3-L1 pre-adipocytes. Both flavones show dose dependent, competitive inhibition of PL activity. Molecular docking studies revealed binding of the flavones to the active site of PL. In 3T3-L1 adipocytes, both flavones reduced the accumulation of lipids and triglycerides. PMF and TMF also lowered the expression of adipogenic and lipogenic genes. They both reduced the expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), sterol regulatory element-binding protein 1 (SREBF 1), fatty acid synthase (FASN), adipocyte binding protein 2 (aP2), and leptin gene. In addition, these flavones enhanced adiponectin mRNA expression, increased lipolysis and enhanced the expression of lipolytic genes: adipose triglycerides lipase (ATGL), hormone sensitive lipase (HSL) and monoglycerides lipase (MAGL) in mature 3T3-L1 adipocytes. Overall, PMF was seen to be a more potent inhibitor of both PL activity and adipogenesis versus TMF. These results suggest that PMF and TMF possess anti-obesity activities and can be further evaluated for their anti-obesity effects.
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Metabolomics based biomarker identification of anti-diabetes and anti-obesity properties of Malaysian herbs. Metabolomics 2022; 18:12. [PMID: 35092490 DOI: 10.1007/s11306-022-01870-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 01/13/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Today, obesity affects over one-third of the global population and is hugely considered the Industrial Revolution's side effect. This multi-factorial disease is continuously spreading across developing countries, including the Middle East and Southeast Asia region, where Malaysia and Darussalam Brunei are the most affected. The sedentary lifestyle and availability of surplus foods have dramatically increased the number of individuals with type 2 diabetes in these countries. Thus, an adequate medical strategy must be developed urgently to address and remedy these diseases. Natural sources have been attracting attention, especially in Malaysia, where most land areas are under plant cover. Metabolomics, as a prophylactic technique, has been used extensively in Malaysia to investigate the potential use and benefits of herbs to combat obesity and diabetes. AIM OF REVIEW This review aims to explain the application of the metabolomics approach in the study of anti-diabetes and anti-obesity activity of Malaysian herbs to identify the stand-up point for future advancement in using these herbs as a primary source for drug exploration. KEY SCIENTIFIC CONCEPTS OF REVIEW This review provides an overview of using metabolomics technique in studying the anti-diabetes and anti-obesity activity of Malaysian herbs. Specific emphasis is given to the changed metabolites in both in vivo and in vitro treatment of Malaysia herbs that might be future drugs for treating diabetes and obesity.
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AgRP/NPY and POMC neurons in the arcuate nucleus and their potential role in treatment of obesity. Eur J Pharmacol 2022; 915:174611. [PMID: 34798121 DOI: 10.1016/j.ejphar.2021.174611] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 02/08/2023]
Abstract
Obesity is a major health crisis affecting over a third of the global population. This multifactorial disease is regulated via interoceptive neural circuits in the brain, whose alteration results in excessive body weight. Certain central neuronal populations in the brain are recognised as crucial nodes in energy homeostasis; in particular, the hypothalamic arcuate nucleus (ARC) region contains two peptide microcircuits that control energy balance with antagonistic functions: agouti-related peptide/neuropeptide-Y (AgRP/NPY) signals hunger and stimulates food intake; and pro-opiomelanocortin (POMC) signals satiety and reduces food intake. These neuronal peptides levels react to energy status and integrate signals from peripheral ghrelin, leptin, and insulin to regulate feeding and energy expenditure. To manage obesity comprehensively, it is crucial to understand cellular and molecular mechanisms of information processing in ARC neurons, since these regulate energy homeostasis. Importantly, a specific strategy focusing on ARC circuits needs to be devised to assist in treating obese patients and maintaining weight loss with minimal or no side effects. The aim of this review is to elucidate the recent developments in the study of AgRP-, NPY- and POMC-producing neurons, specific to their role in controlling metabolism. The impact of ghrelin, leptin, and insulin signalling via action of these neurons is also surveyed, since they also impact energy balance through this route. Lastly, we present key proteins, targeted genes, compounds, drugs, and therapies that actively work via these neurons and could potentially be used as therapeutic targets for treating obesity conditions.
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Whole-genome sequence and broad-spectrum antibacterial activity of Chryseobacterium cucumeris strain MW-6 isolated from the Arabian Sea. 3 Biotech 2021; 11:489. [PMID: 34790513 DOI: 10.1007/s13205-021-03039-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 10/21/2021] [Indexed: 11/28/2022] Open
Abstract
In the current study, Chryseobacterium cucumeris strain MW-6 isolated from Arabian seawater exhibited broad-spectrum antibacterial activity against indicator bacterial pathogens. The partially extracted antibacterial metabolites with ethyl acetate revealed promising activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Listeria monocytogenes, and Staphylococcus aureus. The minimum inhibitory concentrations (MICs) were determined against indicator strains that ranged from 65-90 µg/ml. The genome size of C. cucumeris MW-6 is 4.81 Mbs containing 4227 coding DNA sequences, 74 tRNAs, 3 rRNAs, and 3 ncRNAs genes with 36.90% GC contents. The genome harbors nine putative biosynthetic gene clusters (BGCs) involved in the biosynthesis of lanthipeptide, NRPS-like, RiPPs-like, terpene, microviridin, T1PKS (hg1E-KS), resorcinol, and siderophore. Additionally, the strain encodes genes for sodium/proton antiporter, glutathione, superoxide dismutase, and cold shock protein to survive under stress conditions such as osmotic, oxidative, and cold shock. These putative BGCs and stress-related genes can be associated with in-vitro antibacterial activities and adaptation of this strain to the marine environment. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-03039-5.
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Brown/Beige adipose tissues and the emerging role of their secretory factors in improving metabolic health: The batokines. Biochimie 2021; 184:26-39. [PMID: 33548390 DOI: 10.1016/j.biochi.2021.01.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/22/2020] [Accepted: 01/28/2021] [Indexed: 12/12/2022]
Abstract
Brown and beige adipose tissues are the primary sites for adaptive non-shivering thermogenesis. Although they have been known principally for their thermogenic effects, in recent years, it has emerged that, just like white adipose tissue (WAT), brown and beige adipose tissues also play an important role in the regulation of metabolic health through secretion of various brown adipokines (batokines) in response to various physiological cues. These secreted batokines target distant organs and tissues such as the liver, heart, skeletal muscles, brain, WAT, and perform various local and systemic functions in an autocrine, paracrine, or endocrine manner. Brown and beige adipose tissues are therefore now receiving increasing levels of attention with respect to their effects on various other organs and tissues. Identification of novel secreted factors by these tissues may help in the discovery of drug candidates for the treatment of various metabolic disorders such as obesity, type-2 diabetes, skeletal deformities, cardiovascular diseases, dyslipidemia. In this review, we comprehensively describe the emerging secretory role of brown/beige adipose tissues and the metabolic effects of various brown/beige adipose tissues secreted factors on other organs and tissues in endocrine/paracrine manners, and as well as on brown/beige adipose tissue itself in an autocrine manner. This will provide insights into understanding the potential secretory role of brown/beige adipose tissues in improving metabolic health.
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Mechanisms of action for the anti-obesogenic activities of phytochemicals. PHYTOCHEMISTRY 2020; 180:112513. [PMID: 33010536 DOI: 10.1016/j.phytochem.2020.112513] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
The prevalence of obesity is increasing rapidly globally and has recently reached pandemic proportions. It is a multifactorial disorder linked to a number of non-communicable diseases such as type-2 diabetes, cardiovascular disease, and cancer. Over-nutrition and a sedentary lifestyle are considered the most significant causes of obesity; a healthy lifestyle and behavioural interventions are the most powerful ways to achieve successful weight loss, but to maintain this in the long term can prove difficult for many individuals, without medical intervention. Various pharmacological anti-obesogenic drugs have been tested and marketed in the past and have been moderately successful in the management of obesity, but their adverse effects on human health often outweigh the benefits. Natural products from plants, either in the form of crude extracts or purified phytochemicals, have been shown to have anti-obesogenic properties and are generally considered as nontoxic and cost-effective compared to synthetic alternatives. These plant products combat obesity by targeting the various pathways and/or regulatory functions intricately linked to obesity. Their mechanisms of action include inhibition of pancreatic lipase activities, an increase in energy expenditure, appetite regulation, lipolytic effects, and inhibition of white adipose tissue development. In this review, we discuss the distinct anti-obesogenic properties of recently reported plant extracts and specific bioactive compounds, along with their molecular mechanisms of action. This review will provide a common platform for understanding the different causes of obesity and the possible approaches to using plant products in tackling this worldwide health issue.
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Emergence and molecular mechanisms of SARS-CoV-2 and HIV to target host cells and potential therapeutics. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2020; 85:104583. [PMID: 33035643 PMCID: PMC7536551 DOI: 10.1016/j.meegid.2020.104583] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 02/07/2023]
Abstract
The emergence of a new coronavirus, in around late December 2019 which had first been reported in Wuhan, China has now developed into a massive threat to global public health. The World Health Organization (WHO) has named the disease caused by the virus as COVID-19 and the virus which is the culprit was renamed from the initial novel respiratory 2019 coronavirus to SARS-CoV-2. The person-to-person transmission of this virus is ongoing despite drastic public health mitigation measures such as social distancing and movement restrictions implemented in most countries. Understanding the source of such an infectious pathogen is crucial to develop a means of avoiding transmission and further to develop therapeutic drugs and vaccines. To identify the etiological source of a novel human pathogen is a dynamic process that needs comprehensive and extensive scientific validations, such as observed in the Middle East respiratory syndrome (MERS), severe acute respiratory syndrome (SARS), and human immunodeficiency virus (HIV) cases. In this context, this review is devoted to understanding the taxonomic characteristics of SARS-CoV-2 and HIV. Herein, we discuss the emergence and molecular mechanisms of both viral infections. Nevertheless, no vaccine or therapeutic drug is yet to be approved for the treatment of SARS-CoV-2, although it is highly likely that new effective medications that target the virus specifically will take years to establish. Therefore, this review reflects the latest repurpose of existing antiviral therapeutic drug choices available to combat SARS-CoV-2.
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Murine in vitro cellular models to better understand adipogenesis and its potential applications. Differentiation 2020; 115:62-84. [PMID: 32891960 DOI: 10.1016/j.diff.2020.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/08/2020] [Accepted: 08/13/2020] [Indexed: 02/07/2023]
Abstract
Adipogenesis has been extensively studied using in vitro models of cellular differentiation, enabling long-term regulation of fat cell metabolism in human adipose tissue (AT) material. Many studies promote the idea that manipulation of this process could potentially reduce the prevalence of obesity and its related diseases. It has now become essential to understand the molecular basis of fat cell development to tackle this pandemic disease, by identifying therapeutic targets and new biomarkers. This review explores murine cell models and their applications for study of the adipogenic differentiation process in vitro. We focus on the benefits and limitations of different cell line models to aid in interpreting data and selecting a good cell line model for successful understanding of adipose biology.
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Antimicrobial role of Lactobacillus species as potential probiotics against enteropathogenic bacteria in chickens. J Infect Dev Ctries 2019; 13:130-136. [PMID: 32036348 DOI: 10.3855/jidc.10542] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 12/13/2018] [Indexed: 10/31/2022] Open
Abstract
INTRODUCTION The emergence of antimicrobial resistance among bacterial community resulted in a ban on drugs as the growth promoter in poultry feed. This situation demands to explore alternatives as food supplements with health benefit to poultry. Therefore, probiotic microorganisms, which are considered as safe and possess various health benefits can be a choice. Present study was designed to explore the probiotic potential of the isolated lactobacillus species in chickens. METHODOLOGY Out of 220 samples, 100 Lactobacillus species were isolated from various regions of chicken intestine. They were further characterized on the basis of morphology, staining and catalase test. Species-level identification was made by amplifying Lactobacillus specific 16S rRNA gene. Out of 100 isolates, 21 were selected for sequencing on the basis of band intensity. RESULTS Among 21 sequences, 16 were identified as L. paracasei (n = 6), L. salivarius (n = 3), L. johnsonii (n = 3), and L. agilis, L. fermentum, L. sakei, and L. curvatus (n = 1 each). These strains were found to be significantly acid-tolerant with 81.68 - 85.01% survival rate at pH 2)and bile-tolerant with 81.96 -84.65% survival rate at 0.3% bile. Except three; all strains showed salt tolerance to 2% and 4% NaCl. Among 21 Lactobacillus strains, 6 showed good antimicrobial activities against S. aureus, Salmonella Typhimurium and E. coli. CONCLUSION Lactobacillus species with probiotic property can be used in poultry feed formulation for their health benefit to combat gastrointestinal infections.
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Photocatalytic removal of selenite and selenate species: effect of EDTA and other process variables. ENVIRONMENTAL TECHNOLOGY 2014; 35:1091-1100. [PMID: 24701904 DOI: 10.1080/09593330.2013.861857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
TiO2-assisted photocatalysis was employed for the removal of aqueous phase selenite and selenate species in conjunction with EDTA as a hole (h+) scavenger. Findings from the binary selenite/EDTA and selenate/EDTA systems showed high selenite and selenate removal at pH 4 and pH 6, with faster removal kinetics noted for the selenite species compared with the selenate species that showed a gradual change over the reaction course. The noted removal of selenite and selenate was attributed to their reduction by the conduction band electrons (e-). The effect of pH studies indicated high selenite, selenate, and EDTA removal in the acidic pH range, with the following specific trend: pH 4 > pH 6 > pH 12. Different from the EDTA studies, the use of thiocyanate alone did not initiate reduction of selenium oxyanions, and hence, its role as a hole scavenger in the present systems was not evident. However, the addition of EDTA to respective selenite/selenate/thiocyanate system at pH 4 did yield near complete removal of selenite and selenate species. The marginal role of thiocyanate as a hole scavenger was attributed to its negligible adsorption onto TiO2 surface. Furthermore, at pH 4 and within 3 h reaction time, enhanced selenate removal was noted with an increase in its initial concentration from 20 to 100 ppm, with near complete selenate removal noted for both cases. In general, findings from the present work indicate that both selenite and selenate can be successfully removed from the aqueous phase employing the TiO2-mediated photocatalysis and h(+)-scavenging agent EDTA.
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Impact of GDP, spending on R&D, number of universities and scientific journals on research publications in pharmacological sciences in Middle East. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2013; 17:2697-2705. [PMID: 24174349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVES Research in pharmacological science is vital to support the health needs of human beings. Measuring the research output provides information that forms the basis of strategic decisions. This study aimed to investigate the impact of Gross Domestic Product (GDP), spending on Research and Development (R&D), number of universities and scientific journals on research documents (papers), citable documents, citations per document and H-index in pharmacological science among Middle East countries. MATERIALS AND METHODS All the 16 Middle East countries were included in the study. The information regarding GDP, spending on R&D, total number of universities and indexed scientific journals were collected. We recorded the total number of research documents, citable documents, citations per document and H-index in pharmacological science during the period 1996-2011. The main sources for information were World Bank, Web of Science, Journal Citation Reports (Thomson Reuters) and SCI-mago/Scopus. RESULTS The mean per capita GDP of all the Middle East countries is 18125.49±5386.28 US$, spending on R&D 0.63±0.28% of GDP in US$, number of universities 36.56±11.33 and mean ISI indexed journal are 8.25±3.93. The number of research documents published in pharmacological science among the Middle East countries during the period 1996-2011 is 1344.44±499.34; citable documents 1286.37±476.34; citations per document 7.62± 0.84; and H-index is 30.68±6.32. There was a positive correlation between spending on R&D and citations per documents (r = 0.56, p = 0.02), H-Index (r = 0.56, p = 0.02); number of universities and research documents (r = 0.72, p = 0.002), citable documents (r = 0.72, p = 0.001); ISI indexed journals and research documents (r = 0.88, p = 0.0001), citable documents (r = 0.88, p = 0.0001), H-Index (r = 0.67, p = 0.004). However, there was no correlation between the GDP per capita and research outcome in pharmacological science. CONCLUSIONS There is a positive association between spending on R&D, number of universities and indexed scientific journals on research outcome in pharmacological science in Middle East.
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NH4+-NH3 removal from simulated wastewater using UV-TiO2 photocatalysis: effect of co-pollutants and pH. ENVIRONMENTAL TECHNOLOGY 2010; 31:641-654. [PMID: 20540426 DOI: 10.1080/09593331003596536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The main objective of the present study was to investigate the efficiency of titanium dioxide (TiO2) assisted photocatalytic degradation (PCD) process for the removal of ammonium-ammonia (NH4(+)-NH3) from the aqueous phase and in the presence of co-pollutants thiosulfate (S2O3(2-)) and p-cresol (C6H4CH3OH) under varying mixed conditions. For the NH4(+)-NH3 only PCD experiments, results showed higher NH4 -NH3 removal at pH 12 compared to pH 7 and 10. For the binary NH4(+)-NH3/S2O3(2-) studies the respective results indicated a significant lowering in NH4(+)-NH3 PCD in the presence of S2O32- at pH 7/12 whereas at pH 10 a marked increase in NH4(+)-NH3 removal transpired. A similar trend was noted for the p-cresol/NH4(+)-NH3 binary system. Comparing findings from the binary (NH4(+)-NH3/S2O3(2-) and p-cresol/NH4(+)-NH3) and tertiary (NH4(+)-NH3/S2O3(2-)/p-cresol) systems, at pH 10, showed fastest NH4(+)-NH3 removal transpiring for the tertiary system as compared to the binary systems, whereas both the binary systems indicated comparable NH4(+)-NH3 removal trends. The respective details have been discussed.
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Enhanced photocatalytic activity of nafion-coated TiO2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:411-415. [PMID: 11347618 DOI: 10.1021/es001238q] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Photocatalytic degradation (PCD) of aqueous paraquat was accelerated by the addition of either phosphate or sulfate salt. Attachment of these anions to the TiO2 surface possibly results in increased adsorption of the cationic paraquat species and in turn its photocatalysis rate. The same effect was obtained more consistently using the Nafion (an anionic polymer)-coated TiO2. Enhanced PCD of paraquat and some amine compounds was noted. However the anionic and neutral compounds were not affected significantly. Nafion proved to be stable against photocatalysis. It has been suggested that the degradation rate is larger for the cationic compounds with higher pK(B). For a phenol-paraquat-TiO2 system, paraquat degradation did not begin till near-complete phenol removal. Using the Nafion-coated TiO2, both phenol and paraquat degradations started simultaneously. Nevertheless, complete paraquat removal still took longer than phenol.
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Subcellular localization of dystrophin and vinculin in cardiac muscle fibers and fibers of the conduction system of the chicken ventricle. Cell Tissue Res 1998; 294:137-43. [PMID: 9724463 DOI: 10.1007/s004410051163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The subcellular localization of dystrophin and vinculin was investigated in cardiac muscle fibers and fibers of the conduction system of the chicken ventricle by immunofluorescence confocal microscopy. In ventricular cardiac muscle fibers, strong staining with antibody against dystrophin appeared as regularly arranged transverse striations at the sarcolemmal surface, and faint but uniform staining was seen in narrow strips between these striations. In fibers of the ventricular conduction system, the sarcolemma was stained uniformly with this antibody, but strong staining was found as regular striations in many areas and as scattered patches in other areas of the sarcolemma. These intensely stained striations and scattered patches of dystrophin were colocalized with those of vinculin. Because dystrophin striations were located at the level of Z bands of the underlying myofibrils, they were regarded as the concentration of this protein at costameres together with vinculin. In fibers of the conduction system, myofibrils were close to the sarcolemma where dystrophin and vinculin assumed a striated pattern, at some distance from the cell membrane where these proteins exhibited a patchy distribution, and distant from the sarcolemma where dystrophin was uniformly distributed. These data suggest that the distribution patterns of dystrophin reflect the degree of association between the sarcolemma and underlying myofibrils.
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Abstract
Nitrilotriacetic acid (NTA) is extensively used in different industries because of its excellent chelating properties. Introduction of NTA into the natural environment is a concern because of mobilization of heavy metal species that may be otherwise bound to natural particulate matter. The present study investigates the adsorption behavior of Pb(II) and NTA, both as individual species and as complex species onto titanium dioxide. This adsorption information is important in considering the TiO2-assisted photocatalytic treatment of these metal-organic complexes. Pb(II) shows a typical cationic type of adsorption behavior, whereas NTA demonstrates an anionic type of adsorption trend. Results from stoichiometric ternary systems show a gradual increase in Pb(II) adsorption and a decrease in NTA removal with an increase in pH. However, for the cases of Pb(II) > NTA, increased NTA adsorption as compared to pure NTA systems was noted even at higher pH. Model predictions employing MINTEQA2 software followed the experimental trends. Experimental and model results from ternary systems suggest adsorption of free Pb(II) and NTA, as well as ternary Ti-NTA-Pb(II) and Ti-O-Pb(II)-NTA2- species. The cationic-type complexation, i.e., Ti-O-Pb(II)-NTA2-, was essential for the successful NTA adsorption modeling, especially at higher pH and for Pb > NTA systems, where significant NTA adsorption was noted even at very high pH values. Most of the previous metal-ligand adsorption studies did not consider such a surface complexation. However, the present results indicate that any groundwater transport modeling of such pollutants will require the inclusion of cationic-type surface complexation, in addition to other surface species. Copyright 1997 Academic Press. Copyright 1997Academic Press
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