A vital part of PIPAC’s package of services is basic and applied research conducted independently or in cooperation with client companies.
Institute Personnel and their Research Interests
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Armando Victor M. Guidote, Jr., Ph.D.
Research Interests:
Organic Chemistry, Natural Products, Chemistry Education
Click here to see the list of his publications.
Armando Jerome H. de Jesus, Jr., Ph.D.
Research Interests:
Molecular dynamics simulations, Membrane-protein interactions, Membrane protein-small molecule interactions
Click here to see the list of his publications.
Ronaldo M. Fabicon, Ph.D.
Research Interests:
Industrial Chemistry
Click here to see the list of his publications.
Crisanto M. Lopez, Dr.rer.nat
Research Interests:
Infection Biology, Fungal Biotechnology
Click here to see the list of his publications.
Giselle Grace F. Lim-Co Yu Kang, Ph.D
Research Interests:
Biochemistry, Enzymes, Analytical Chemistry
Click here to see the list of her publications.
Gilbert U. Yu, D.Eng
Research Interests:
Materials Science (Polymers and Supramolecules), Chemical Education, Development of Lab Experiment Modules
Click here to see the list of his publications.
Ian Ken D. Dimzon, Ph.D
Research Interests:
Applied Analytical Chemistry, Mass Spectrometry, Chemical Metrology
Click here to see the list of his publications.
Anna Carissa M. San Esteban, Ph.D
Research Interests:
Electrochemistry (corrosion, electrocatalytic processes); Coordination Chemistry (coordination polymers, metal-organic frameworks)
Click here to see the list of her publications.
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Selected Publications
2020
Ignacio Aguirre-Ayerbe; María Merino; Seinn Lei Aye; Ranjith Dissanayake; Fathimath Shadiya; Crisanto M. Lopez
An evaluation of availability and adequacy of Multi-Hazard Early Warning Systems in Asian countries: A baseline study Journal Article
In: International Journal of Disaster Risk Reduction, vol. 49, pp. 101749, 2020.
@article{Aguirre-Ayerbe2020,
title = {An evaluation of availability and adequacy of Multi-Hazard Early Warning Systems in Asian countries: A baseline study},
author = {Ignacio Aguirre-Ayerbe and María Merino and Seinn Lei Aye and Ranjith Dissanayake and Fathimath Shadiya and Crisanto M. Lopez},
url = {https://www.sciencedirect.com/science/article/pii/S2212420920302582},
doi = {10.1016/j.ijdrr.2020.101749},
year = {2020},
date = {2020-07-08},
journal = {International Journal of Disaster Risk Reduction},
volume = {49},
pages = {101749},
abstract = {Early warning systems are widely considered as one of the more important aspects to reduce the impacts and consequences that hazardous natural events pose to societies. Similar to the other terms related to disaster risk reduction, this concept has evolved over time to eventually result in a comprehensive framework, that includes features from the upstream phase, such as detection and forecasting tools and models, to the downstream phase that considers a people-centred approach.
Based on this holistic conceptual framework, this paper attempts to assess the degree of adequacy and integration of early warning systems with reference to international standards using a multi-hazard perspective. The study is focused on the following Asian countries: the Maldives, Sri Lanka, Myanmar and the Philippines.
Results obtained provide an inventory of existing approaches and systems, showing common backgrounds and consistencies in their conceptualisation. In addition, the findings of this study highlight the strengths and weaknesses of Multi-Hazard Early Warning Systems in each country considering their technical, legal, and socio-economic complexities. These findings are intended to support target countries to improve the availability and effectiveness of their warning systems.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Early warning systems are widely considered as one of the more important aspects to reduce the impacts and consequences that hazardous natural events pose to societies. Similar to the other terms related to disaster risk reduction, this concept has evolved over time to eventually result in a comprehensive framework, that includes features from the upstream phase, such as detection and forecasting tools and models, to the downstream phase that considers a people-centred approach.
Based on this holistic conceptual framework, this paper attempts to assess the degree of adequacy and integration of early warning systems with reference to international standards using a multi-hazard perspective. The study is focused on the following Asian countries: the Maldives, Sri Lanka, Myanmar and the Philippines.
Results obtained provide an inventory of existing approaches and systems, showing common backgrounds and consistencies in their conceptualisation. In addition, the findings of this study highlight the strengths and weaknesses of Multi-Hazard Early Warning Systems in each country considering their technical, legal, and socio-economic complexities. These findings are intended to support target countries to improve the availability and effectiveness of their warning systems.
Based on this holistic conceptual framework, this paper attempts to assess the degree of adequacy and integration of early warning systems with reference to international standards using a multi-hazard perspective. The study is focused on the following Asian countries: the Maldives, Sri Lanka, Myanmar and the Philippines.
Results obtained provide an inventory of existing approaches and systems, showing common backgrounds and consistencies in their conceptualisation. In addition, the findings of this study highlight the strengths and weaknesses of Multi-Hazard Early Warning Systems in each country considering their technical, legal, and socio-economic complexities. These findings are intended to support target countries to improve the availability and effectiveness of their warning systems.
2017
Sascha Klein; Ian Ken D. Dimzon; Jan Eubeler; Thomas P. Knepper
In: Freshwater Microplastics, vol. 58, pp. 51-67, Springer, Cham, 2017, ISBN: 978-3-319-61615-5.
@inbook{Klein2017,
title = {Analysis, Occurrence, and Degradation of Microplastics in the Aqueous Environment microplastics in the aqueous environment},
author = {Sascha Klein and Ian Ken D. Dimzon and Jan Eubeler and Thomas P. Knepper},
url = {https://link.springer.com/chapter/10.1007/978-3-319-61615-5_3},
doi = { 10.1007/978-3-319-61615-5_3},
isbn = {978-3-319-61615-5},
year = {2017},
date = {2017-07-20},
booktitle = {Freshwater Microplastics},
volume = {58},
pages = {51-67},
publisher = {Springer, Cham},
series = {The Handbook of Environmental Chemistry},
abstract = {Synthetic polymers are one of the most significant pollutants in the aquatic environment. Most research focused on small plastic particles, so-called microplastics (particle size, 1–5,000 μm). Compared to macroplastics, the small size complicates their determination in environmental samples and demands for more sophisticated analytical approaches. The detection methods of microplastics reported in the past are highly diverse. This chapter summarizes different strategies for the sampling of water and sediment and sample treatments, including the separation of plastic particles and removal of natural debris that are necessary prior the identification of microplastics. Moreover, the techniques used for the identification of plastics particles are presented in this chapter.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.},
keywords = {-},
pubstate = {published},
tppubtype = {inbook}
}
Synthetic polymers are one of the most significant pollutants in the aquatic environment. Most research focused on small plastic particles, so-called microplastics (particle size, 1–5,000 μm). Compared to macroplastics, the small size complicates their determination in environmental samples and demands for more sophisticated analytical approaches. The detection methods of microplastics reported in the past are highly diverse. This chapter summarizes different strategies for the sampling of water and sediment and sample treatments, including the separation of plastic particles and removal of natural debris that are necessary prior the identification of microplastics. Moreover, the techniques used for the identification of plastics particles are presented in this chapter.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.
2016
Tobias Frömel; Christoph Gremmel; Ian Ken D. Dimzon; Heike Weil; Thomas P. Knepper; Pim de Voogt
Umweltbundesamt, 2016, ISBN: 1862-4804.
@book{Frömel2016,
title = {Investigations on the presence and behavior of precursors to perfluoroalkyl substances in the environment as a preparation of regulatory measures},
author = {Tobias Frömel and Christoph Gremmel and Ian Ken D. Dimzon and Heike Weil and Thomas P. Knepper and Pim de Voogt},
url = {https://www.umweltbundesamt.de/publikationen/investigations-on-the-presence-behavior-of},
isbn = {1862-4804},
year = {2016},
date = {2016-08-01},
publisher = {Umweltbundesamt},
abstract = {Wastewater treatment plants (WWTPs) have been identified as a significant pathway for the introduction of perfluoroalkyl and polyfluoroalkyl substances (PFASs) to natural waters. It was observed in several studies that the concentration of certain PFASs were higher in the WWTP effluent compared to the corresponding influent. The objective of the present study was the identification of potential precursor substances of persistent perfluoroalkyl acids (PFAAs) in WWTPs and indoor rooms in order to support the preparation of regulatory measures.},
keywords = {-},
pubstate = {published},
tppubtype = {book}
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Wastewater treatment plants (WWTPs) have been identified as a significant pathway for the introduction of perfluoroalkyl and polyfluoroalkyl substances (PFASs) to natural waters. It was observed in several studies that the concentration of certain PFASs were higher in the WWTP effluent compared to the corresponding influent. The objective of the present study was the identification of potential precursor substances of persistent perfluoroalkyl acids (PFAAs) in WWTPs and indoor rooms in order to support the preparation of regulatory measures.
Armando J. de Jesus; Ormacinda R. White; Aaron D. Flynn; Hang Yin
Determinants of Curvature-Sensing Behavior for MARCKS-Fragment Peptides Journal Article
In: Biophysical Journal, vol. 110, no. 9, pp. 1980-1992, 2016.
@article{deJesus2016,
title = {Determinants of Curvature-Sensing Behavior for MARCKS-Fragment Peptides},
author = {Armando J. de Jesus and Ormacinda R. White and Aaron D. Flynn and Hang Yin},
url = {https://www.cell.com/biophysj/fulltext/S0006-3495(16)30168-0},
doi = {10.1016/j.bpj.2016.04.007},
year = {2016},
date = {2016-05-10},
journal = {Biophysical Journal},
volume = {110},
number = {9},
pages = {1980-1992},
abstract = {It is increasingly recognized that membrane curvature plays an important role in various cellular activities such as signaling and trafficking, as well as key issues involving health and disease development. Thus, curvature-sensing peptides are essential to the study and detection of highly curved bilayer structures. The effector domain of myristoylated alanine-rich C-kinase substrate (MARCKS-ED) has been demonstrated to have curvature-sensing ability. Research of the MARCKS-ED has further revealed that its Lys and Phe residues play an essential role in how MARCKS-ED detects and binds to curved bilayers. MARCKS-ED has the added property of being a lower-molecular-weight curvature sensor, which offers advantages in production. With that in mind, this work investigates peptide-sequence-related factors that influence curvature sensing and explores whether peptide fragments of even shorter length can function as curvature sensors. Using both experimental and computational methods, we studied the curvature-sensing capabilities of seven fragments of MARCKS-ED. Two of the longer fragments were designed from approximately the two halves of the full-length peptide whereas the five shorter fragments were taken from the central stretch of MARCKS-ED. Fully atomistic molecular dynamics simulations show that the fragments that remain bound to the bilayer exhibit interactions with the bilayer similar to that of the full-length MARCKS-ED peptide. Fluorescence enhancement and anisotropy assays, meanwhile, reveal that five of the MARCKS fragments possess the ability to sense membrane curvature. Based on the sequences of the curvature-sensing fragments, it appears that the ability to sense curvature involves a balance between the numbers of positively charged residues and hydrophobic anchoring residues. Together, these findings help crystallize our understanding of the molecular mechanisms underpinning the curvature-sensing behaviors of peptides, which will prove useful in the design of future curvature sensors.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
It is increasingly recognized that membrane curvature plays an important role in various cellular activities such as signaling and trafficking, as well as key issues involving health and disease development. Thus, curvature-sensing peptides are essential to the study and detection of highly curved bilayer structures. The effector domain of myristoylated alanine-rich C-kinase substrate (MARCKS-ED) has been demonstrated to have curvature-sensing ability. Research of the MARCKS-ED has further revealed that its Lys and Phe residues play an essential role in how MARCKS-ED detects and binds to curved bilayers. MARCKS-ED has the added property of being a lower-molecular-weight curvature sensor, which offers advantages in production. With that in mind, this work investigates peptide-sequence-related factors that influence curvature sensing and explores whether peptide fragments of even shorter length can function as curvature sensors. Using both experimental and computational methods, we studied the curvature-sensing capabilities of seven fragments of MARCKS-ED. Two of the longer fragments were designed from approximately the two halves of the full-length peptide whereas the five shorter fragments were taken from the central stretch of MARCKS-ED. Fully atomistic molecular dynamics simulations show that the fragments that remain bound to the bilayer exhibit interactions with the bilayer similar to that of the full-length MARCKS-ED peptide. Fluorescence enhancement and anisotropy assays, meanwhile, reveal that five of the MARCKS fragments possess the ability to sense membrane curvature. Based on the sequences of the curvature-sensing fragments, it appears that the ability to sense curvature involves a balance between the numbers of positively charged residues and hydrophobic anchoring residues. Together, these findings help crystallize our understanding of the molecular mechanisms underpinning the curvature-sensing behaviors of peptides, which will prove useful in the design of future curvature sensors.
Gilbert U. Yu; Yuji Suzaki; Kohtaro Osakada
Ferrocene-containing [1]-, [2]-, [3]- and [4]rotaxanes synthesized from a common precursor Journal Article
In: RSC Advances, vol. 6, no. 27, pp. 41369-41375, 2016.
@article{Yu2016b,
title = {Ferrocene-containing [1]-, [2]-, [3]- and [4]rotaxanes synthesized from a common precursor},
author = {Gilbert U. Yu and Yuji Suzaki and Kohtaro Osakada},
url = {https://pubs.rsc.org/en/content/articlelanding/2016/RA/C6RA05688A},
doi = {10.1039/C6RA05688A},
year = {2016},
date = {2016-04-26},
journal = {RSC Advances},
volume = {6},
number = {27},
pages = {41369-41375},
abstract = {The Cu-catalyzed reaction of a dialkylammonium, having ferrocenyl and hexynyl end groups, FcCH2NH2CH2C6H4–4-O(CH2)4C[triple bond, length as m-dash]CH]PF6 (Fc = Fe(C5H4)(C5H5)), with a crown ether having an azidemethyl side-arm yields a [1]rotaxane composed of a single molecule. The crystal structure of the [1]rotaxane suggests an arrangement where the 1,4-phenylene ring is tilted at 22° close to the catechol ring rather than in a parallel alignment. Another dialkylammonium with ferrocenyl and alkynyl terminal groups, [FcCH2NH2CH2C6H4–4-O(CH2)4C[triple bond, length as m-dash]CH]PF6, reacts with aromatic compounds with one to three azide groups in the presence of dibenzo[24]crown-8-ether (DB24C8) and [Cu(MeCN)4]PF6 catalyst, to afford the corresponding [2]–[4]rotaxanes. The products contain DB24C8 molecules as the cyclic components which are bound to the ammonium group of the axle component with NH⋯O hydrogen bonding. The [3]rotaxane having two triazole groups on the axle component reacts with PdCl2(MeCN)2 to yield mono- and di-palladium complexes with different conformations of the axle component.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
The Cu-catalyzed reaction of a dialkylammonium, having ferrocenyl and hexynyl end groups, FcCH2NH2CH2C6H4–4-O(CH2)4C[triple bond, length as m-dash]CH]PF6 (Fc = Fe(C5H4)(C5H5)), with a crown ether having an azidemethyl side-arm yields a [1]rotaxane composed of a single molecule. The crystal structure of the [1]rotaxane suggests an arrangement where the 1,4-phenylene ring is tilted at 22° close to the catechol ring rather than in a parallel alignment. Another dialkylammonium with ferrocenyl and alkynyl terminal groups, [FcCH2NH2CH2C6H4–4-O(CH2)4C[triple bond, length as m-dash]CH]PF6, reacts with aromatic compounds with one to three azide groups in the presence of dibenzo[24]crown-8-ether (DB24C8) and [Cu(MeCN)4]PF6 catalyst, to afford the corresponding [2]–[4]rotaxanes. The products contain DB24C8 molecules as the cyclic components which are bound to the ammonium group of the axle component with NH⋯O hydrogen bonding. The [3]rotaxane having two triazole groups on the axle component reacts with PdCl2(MeCN)2 to yield mono- and di-palladium complexes with different conformations of the axle component.
2015
Ian Ken D. Dimzon
Analytical and Statistical Approaches in the Characterization of Synthetic Polymers Book
Proefschrift Universiteit van Amsterdam, 2015, ISBN: 9789491407178.
@book{Dimzon2015b,
title = {Analytical and Statistical Approaches in the Characterization of Synthetic Polymers},
author = {Ian Ken D. Dimzon},
url = {https://dare.uva.nl/search?identifier=e5fe675e-b25c-48af-bc9a-3bc9e99c8763},
isbn = {9789491407178},
year = {2015},
date = {2015-05-22},
pages = {157},
publisher = {Proefschrift Universiteit van Amsterdam},
abstract = {Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a given polymer. Multi-technique but polymer-specific approach was found to be an appropriate alternative. This strategy was applied in characterizing polymers of a wide range of properties from simple polyethylene gylcol, to polycationic chitosan and aminopropyl based oligosiloxanes, and to polydiverse polyfluorinated polyethoxylates.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.},
keywords = {-},
pubstate = {published},
tppubtype = {book}
}
Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a given polymer. Multi-technique but polymer-specific approach was found to be an appropriate alternative. This strategy was applied in characterizing polymers of a wide range of properties from simple polyethylene gylcol, to polycationic chitosan and aminopropyl based oligosiloxanes, and to polydiverse polyfluorinated polyethoxylates.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.
2014
Crisanto M. Lopez; Reinhard Wallich; Kristian Riesbeck; Christine Skerka; Peter F. Zipfel
Candida albicans Uses the Surface Protein Gpm1 to Attach to Human Endothelial Cells and to Keratinocytes via the Adhesive Protein Vitronectin Journal Article
In: PLoS ONE, vol. 9, no. 3, pp. e90796, 2014.
@article{Lopez2014,
title = {Candida albicans Uses the Surface Protein Gpm1 to Attach to Human Endothelial Cells and to Keratinocytes via the Adhesive Protein Vitronectin},
author = {Crisanto M. Lopez and Reinhard Wallich and Kristian Riesbeck and Christine Skerka and Peter F. Zipfel},
url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0090796},
doi = {10.1371/journal.pone.0090796},
year = {2014},
date = {2014-03-13},
journal = {PLoS ONE},
volume = {9},
number = {3},
pages = {e90796},
abstract = {Candida albicans is a major cause of invasive fungal infections worldwide. Upon infection and when in contact with human plasma as well as body fluids the fungus is challenged by the activated complement system a central part of the human innate immune response. C. albicans controls and evades host complement attack by binding several human complement regulators like Factor H, Factor H-like protein 1 and C4BP to the surface. Gpm1 (Phosphoglycerate mutase 1) is one fungal Factor H/FHL1 -binding protein. As Gpm1 is surface exposed, we asked whether Gpm1 also contributes to host cell attachment. Here, we show by flow cytometry and by laser scanning microscopy that candida Gpm1 binds to human umbilical vein endothelial cells (HUVEC) to keratinocytes (HaCaT), and also to monocytic U937 cells. Wild type candida did bind, but the candida gpm1Δ/Δ knock-out mutant did not bind to these human cells. In addition Gpm1when attached to latex beads also conferred attachment to human endothelial cells. When analyzing Gpm1-binding to a panel of extracellular matrix proteins, the human glycoprotein vitronectin was identified as a new Gpm1 ligand. Vitronectin is a component of the extracellular matrix and also a regulator of the terminal complement pathway. Vitronectin is present on the surface of HUVEC and keratinocytes and acts as a surface ligand for fungal Gpm1. Gpm1 and vitronectin colocalize on the surface of HUVEC and HaCaT as revealed by laser scanning microscopy. The Gpm1 vitronectin interaction is inhibited by heparin and the interaction is also ionic strength dependent. Taken together, Gpm1 the candida surface protein binds to vitronectin and mediates fungal adhesion to human endothelial cells. Thus fungal Gpm1 and human vitronectin represent a new set of proteins that are relevant for fungal attachment to human cells interaction. Blockade of the Gpm1 vitronectin interaction might provide a new target for therapy.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Candida albicans is a major cause of invasive fungal infections worldwide. Upon infection and when in contact with human plasma as well as body fluids the fungus is challenged by the activated complement system a central part of the human innate immune response. C. albicans controls and evades host complement attack by binding several human complement regulators like Factor H, Factor H-like protein 1 and C4BP to the surface. Gpm1 (Phosphoglycerate mutase 1) is one fungal Factor H/FHL1 -binding protein. As Gpm1 is surface exposed, we asked whether Gpm1 also contributes to host cell attachment. Here, we show by flow cytometry and by laser scanning microscopy that candida Gpm1 binds to human umbilical vein endothelial cells (HUVEC) to keratinocytes (HaCaT), and also to monocytic U937 cells. Wild type candida did bind, but the candida gpm1Δ/Δ knock-out mutant did not bind to these human cells. In addition Gpm1when attached to latex beads also conferred attachment to human endothelial cells. When analyzing Gpm1-binding to a panel of extracellular matrix proteins, the human glycoprotein vitronectin was identified as a new Gpm1 ligand. Vitronectin is a component of the extracellular matrix and also a regulator of the terminal complement pathway. Vitronectin is present on the surface of HUVEC and keratinocytes and acts as a surface ligand for fungal Gpm1. Gpm1 and vitronectin colocalize on the surface of HUVEC and HaCaT as revealed by laser scanning microscopy. The Gpm1 vitronectin interaction is inhibited by heparin and the interaction is also ionic strength dependent. Taken together, Gpm1 the candida surface protein binds to vitronectin and mediates fungal adhesion to human endothelial cells. Thus fungal Gpm1 and human vitronectin represent a new set of proteins that are relevant for fungal attachment to human cells interaction. Blockade of the Gpm1 vitronectin interaction might provide a new target for therapy.
2013
Armando J. de Jesus; Noah Kastelowitz; Hang Yin
Changes in lipid density induce membrane curvature Journal Article
In: RSC Advances, vol. 3, no. 33, pp. 13622-13625, 2013.
@article{deJesus2013,
title = {Changes in lipid density induce membrane curvature},
author = {Armando J. de Jesus and Noah Kastelowitz and Hang Yin},
url = {https://pubs.rsc.org/en/content/articlelanding/2013/RA/c3ra42332h},
doi = {10.1039/C3RA42332H},
year = {2013},
date = {2013-06-18},
journal = {RSC Advances},
volume = {3},
number = {33},
pages = {13622-13625},
abstract = {Highly curved bilayer lipid membranes make up the shell of many intra- and extracellular compartments, including organelles and vesicles. Using all-atom molecular dynamics simulations, we show that increasing the density of lipids in the bilayer membrane can induce the membrane to form a curved shape.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Highly curved bilayer lipid membranes make up the shell of many intra- and extracellular compartments, including organelles and vesicles. Using all-atom molecular dynamics simulations, we show that increasing the density of lipids in the bilayer membrane can induce the membrane to form a curved shape.
2009
Jan Julian Marie-Louise Billiauw; Wesley Y. P. Boers; Joseph T. Chio; Ronaldo M. Fabicon; Biyan Huang; Jing Li; Nixon L. Ocampochua; Sylvain A. Sorin; Joia K. Spooner-Wyman
Low sudsing hand washing liquid laundry detergent Patent
US20090229057A1, 2009.
@patent{Billiauw2009,
title = {Low sudsing hand washing liquid laundry detergent},
author = {Jan Julian Marie-Louise Billiauw and Wesley Y. P. Boers and Joseph T. Chio and Ronaldo M. Fabicon and Biyan Huang and Jing Li and Nixon L. Ocampochua and Sylvain A. Sorin and Joia K. Spooner-Wyman},
url = {http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&d=PG01&s1=20090229057.PGNR.},
year = {2009},
date = {2009-09-17},
number = {US20090229057A1},
abstract = {A hand laundering method contains the steps of providing a liquid laundry detergent, diluting the liquid laundry detergent, hand washing laundry and rinsing the laundry. The liquid laundry detergent has a pH of from 7-13 and contains 3-40% of a sudsing surfactant, 0.01-1% of a silicone-containing suds suppressor, 25-85% water, and the balance other ingredients. The liquid laundry detergent is diluted about 1:150-1:1000 with water in a container to form a laundry liquor. Liquid laundry detergents and a method of saving water using such liquid laundry detergents are also described.},
keywords = {-},
pubstate = {published},
tppubtype = {patent}
}
A hand laundering method contains the steps of providing a liquid laundry detergent, diluting the liquid laundry detergent, hand washing laundry and rinsing the laundry. The liquid laundry detergent has a pH of from 7-13 and contains 3-40% of a sudsing surfactant, 0.01-1% of a silicone-containing suds suppressor, 25-85% water, and the balance other ingredients. The liquid laundry detergent is diluted about 1:150-1:1000 with water in a container to form a laundry liquor. Liquid laundry detergents and a method of saving water using such liquid laundry detergents are also described.
2007
Fabian M. Dayrit; Olivia Erin M. Buenafe; Edward T. Chainani; Ian Mitchelle S. de Vera; Ian Ken D. Dimzon; Estrella G. Gonzales; Jaclyn Elizabeth R. Santos
Essential quality parameters of commercial virgin coconut oil Journal Article
In: Cord, vol. 23, no. 1, pp. 71-80, 2007.
@article{Dayrit2007b,
title = {Essential quality parameters of commercial virgin coconut oil},
author = {Fabian M. Dayrit and Olivia Erin M. Buenafe and Edward T. Chainani and Ian Mitchelle S. de Vera and Ian Ken D. Dimzon and Estrella G. Gonzales and Jaclyn Elizabeth R. Santos},
url = {https://library.apccsec.org/paneladmin/doc/20170827054843Fabian%20M.%20Dayrit.pdf},
year = {2007},
date = {2007-01-01},
journal = {Cord},
volume = {23},
number = {1},
pages = {71-80},
abstract = {Chemical analyses conducted on commercial samples of virgin coconut oil (VCO) produced by four different methods gave the following ranges of values: % Fatty acid composition: C6: 0.24 to 0.49%; C8: 4.15 to 8.30%; C10: 4.27 to 5.75%; C12: 46.0 to 52.6%; C14: 16.0 to 19.7%; C16: 7.65 to 10.1%; C18: 2.86 to 4.63%; C18:1: 5.93 to 8.53%; C18:2: 1.00 to 2.16%; %moisture by Karl Fischer: 0.05 to 0.12%; %matter volatile at 120 0C: 0.12 to 0.18%; %free fatty acids as lauric acid: 0.042 to 0.329%; and peroxide value: none detected to 1.40. The tests for %moisture by Karl Fischer and %matter volatile at 120 0C can be used to differentiate VCO from and refined, bleached and deodorized coconut oil (RBD CNO). No trans-fatty acid was detected in both VCO and RBD CNO down to 0.01% (w/w) detection limit.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Chemical analyses conducted on commercial samples of virgin coconut oil (VCO) produced by four different methods gave the following ranges of values: % Fatty acid composition: C6: 0.24 to 0.49%; C8: 4.15 to 8.30%; C10: 4.27 to 5.75%; C12: 46.0 to 52.6%; C14: 16.0 to 19.7%; C16: 7.65 to 10.1%; C18: 2.86 to 4.63%; C18:1: 5.93 to 8.53%; C18:2: 1.00 to 2.16%; %moisture by Karl Fischer: 0.05 to 0.12%; %matter volatile at 120 0C: 0.12 to 0.18%; %free fatty acids as lauric acid: 0.042 to 0.329%; and peroxide value: none detected to 1.40. The tests for %moisture by Karl Fischer and %matter volatile at 120 0C can be used to differentiate VCO from and refined, bleached and deodorized coconut oil (RBD CNO). No trans-fatty acid was detected in both VCO and RBD CNO down to 0.01% (w/w) detection limit.
2001
Ronaldo M. Fabicon; Herman G. Richey Jr.
Formation of organozincate species from diorganozinc compounds and salts Journal Article
In: Journal of the Chemical Society, Dalton Transactions, no. 6, pp. 783-788, 2001.
@article{Fabicon2001,
title = {Formation of organozincate species from diorganozinc compounds and salts},
author = {Ronaldo M. Fabicon and Herman G. Richey Jr.},
url = {https://pubs.rsc.org/en/content/articlelanding/2001/dt/b009126j},
doi = {10.1039/B009126J},
year = {2001},
date = {2001-02-16},
journal = {Journal of the Chemical Society, Dalton Transactions},
number = {6},
pages = {783-788},
abstract = {Stirring a benzene solution of a diorganozinc compound with an insoluble alkali metal alkoxide (MeOK or MeONa) or potassium amide (PhN(Me)K) formed a solution containing a species having a salt ∶ R2Zn composition of 1 ∶ 2. A salt (t-BuOK) that is soluble in benzene also forms a 1 ∶ 2 species and, when the salt to R2Zn ratio is sufficiently high, forms a 1 ∶ 1 species. Controlled heating at reduced pressure of solutions prepared from an alkali metal alkoxide and an excess of a diorganozinc compound leaves materials with alkoxide ∶ R2Zn ratios of 1 ∶ 2 or 1 ∶ 1. Reactions of benzene solutions of diorganozinc compounds with ( p-MeC6H4)SK or Ph2PK form solutions of composition R3ZnK.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Stirring a benzene solution of a diorganozinc compound with an insoluble alkali metal alkoxide (MeOK or MeONa) or potassium amide (PhN(Me)K) formed a solution containing a species having a salt ∶ R2Zn composition of 1 ∶ 2. A salt (t-BuOK) that is soluble in benzene also forms a 1 ∶ 2 species and, when the salt to R2Zn ratio is sufficiently high, forms a 1 ∶ 1 species. Controlled heating at reduced pressure of solutions prepared from an alkali metal alkoxide and an excess of a diorganozinc compound leaves materials with alkoxide ∶ R2Zn ratios of 1 ∶ 2 or 1 ∶ 1. Reactions of benzene solutions of diorganozinc compounds with ( p-MeC6H4)SK or Ph2PK form solutions of composition R3ZnK.
1994
Fabian M. Dayrit; Armando M. Guidote Jr.; Maximino L. Generalao; Constante Serna
Determination of the Quinine Content in the Bark of the Cinchona Tree Grown in Mt. Kitanglad, Bukidnon Journal Article
In: Philippine Journal of Science, vol. 123, no. 3, pp. 215-227, 1994.
@article{Dayrit1994,
title = {Determination of the Quinine Content in the Bark of the Cinchona Tree Grown in Mt. Kitanglad, Bukidnon},
author = {Fabian M. Dayrit and Armando M. Guidote Jr. and Maximino L. Generalao and Constante Serna},
url = {https://philjournalsci.dost.gov.ph/publication/regular-issues/past-issues},
year = {1994},
date = {1994-07-01},
journal = {Philippine Journal of Science},
volume = {123},
number = {3},
pages = {215-227},
abstract = {A rapid, accurate, and inexpensive quantitative HPTLC/densitometry procedure was developed for the simultaneous determination of the four major alkaloids found in the bark of Cinchona species: quinine, quinidine, cinchonine, and cinchonidine. Linearity and % recovery of the procedure were good. This procedure was applied to the analysis of bark samples from seven Cinchona species found in the DENR Cinchona Reforestation Project located in Mt. Kitanglad, Bukidnon: C. calisaya, C. hybrida, C. kartamanah, C. ledgeriana, C. officinalis, C. succirubra, and C. tjinjiroena. The species with the highest % quinine yield were C. ledgeriana, C. officinalis, and C. tjinjiroena.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
A rapid, accurate, and inexpensive quantitative HPTLC/densitometry procedure was developed for the simultaneous determination of the four major alkaloids found in the bark of Cinchona species: quinine, quinidine, cinchonine, and cinchonidine. Linearity and % recovery of the procedure were good. This procedure was applied to the analysis of bark samples from seven Cinchona species found in the DENR Cinchona Reforestation Project located in Mt. Kitanglad, Bukidnon: C. calisaya, C. hybrida, C. kartamanah, C. ledgeriana, C. officinalis, C. succirubra, and C. tjinjiroena. The species with the highest % quinine yield were C. ledgeriana, C. officinalis, and C. tjinjiroena.
1993
Ronaldo M. Fabicon; Anthony D. Pajerski; Herman G. Richey Jr.
Reactions of Grignard reagents with an azacrown ether: syntheses of RMg(14N4)+RMgX2- and RMg(14N4)+X- Journal Article
In: Journal of the American Chemical Society, vol. 115, no. 20, pp. 9333-9334, 1993.
@article{Fabicon1993,
title = {Reactions of Grignard reagents with an azacrown ether: syntheses of RMg(14N4)+RMgX2- and RMg(14N4)+X-},
author = {Ronaldo M. Fabicon and Anthony D. Pajerski and Herman G. Richey Jr.},
url = {https://pubs.acs.org/doi/pdf/10.1021/ja00073a077},
doi = {10.1021/ja00073a077},
year = {1993},
date = {1993-10-01},
journal = {Journal of the American Chemical Society},
volume = {115},
number = {20},
pages = {9333-9334},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
1991
Ronaldo M. Fabicon; Anthony D. Pajerski; Herman G. Richey Jr.
Formation of organozinc cations and anions from diorganozinc compounds Journal Article
In: Journal of the American Chemical Society, vol. 113, no. 17, pp. 6680-6681, 1991.
@article{Fabicon1991,
title = {Formation of organozinc cations and anions from diorganozinc compounds},
author = {Ronaldo M. Fabicon and Anthony D. Pajerski and Herman G. Richey Jr.},
url = {https://pubs.acs.org/doi/pdf/10.1021/ja00017a053},
doi = {10.1021/ja00017a053},
year = {1991},
date = {1991-08-01},
journal = {Journal of the American Chemical Society},
volume = {113},
number = {17},
pages = {6680-6681},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Ronaldo M. Fabicon; Masood Parvez; Herman G. Richey Jr.
Formation of organozincate ions from diorganozinc compounds and potassium alkoxides Journal Article
In: Journal of the American Chemical Society, vol. 113, no. 4, pp. 1412-1414, 1991.
@article{Fabicon1991b,
title = {Formation of organozincate ions from diorganozinc compounds and potassium alkoxides},
author = {Ronaldo M. Fabicon and Masood Parvez and Herman G. Richey Jr.},
url = {https://pubs.acs.org/doi/abs/10.1021/ja00004a053},
doi = {10.1021/ja00004a053},
year = {1991},
date = {1991-02-01},
journal = {Journal of the American Chemical Society},
volume = {113},
number = {4},
pages = {1412-1414},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}