Hamid Ansarian - Academia.edu (original) (raw)

Papers by Hamid Ansarian

Research paper thumbnail of Conformational Effect of Silica-supported Poly(octadecyl acrylate) on Molecular-Shape Selectivity of Polycyclic Aromatic Hydrocarbons in RP-HPLC

Analytical Sciences, Dec 1, 2004

Research paper thumbnail of Temporal variations in COVID-19: an epidemiological discussion with a practical application

Journal of International Medical Research, Aug 1, 2021

ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) i... more ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) infection and mortality as a possible tool to monitor and control the spread of this disease.MethodsWe analyzed cyclicity and synchronicity in cases of COVID-19 infection and time series of deaths using Fourier transform, its inverse method, and statistical treatments. Epidemiological indices (e.g., case fatality rate) were used to quantify the observations in the time series. The possible causes of short-term variations are reviewed.ResultsWe observed that were both short-term and long-term variations in the COVID-19 time series. The short cycles were 7 days and synchronized among all countries. This periodicity is believed to be caused by weekly cycles in community social factors, combined with diagnostic and reporting cycles. This could also be related to virus–host–community dynamics.ConclusionThe observed synchronized weekly cycles could serve as herd defense by providing a form of social distancing in time. The effect of such temporal distancing could be enhanced if combined with spatial distancing. Integrated spatiotemporal distancing is therefore recommended to optimize infection control strategies, taking into account the quiescent and active intervals of COVID-19.

Research paper thumbnail of The impact of supramolecular chemistry in medicine: Removing the border between infectious and non-infectious diseases

Medical Hypotheses, Dec 1, 2008

The concept, molecular self-assembly, has a profoundly novel effect on thoughts and efforts relat... more The concept, molecular self-assembly, has a profoundly novel effect on thoughts and efforts related to medicine and pharmacology. This new style of thinking calls for a range of new researches based on new predictions about disease mechanisms (especially autoimmune diseases, endocrinopathies, and neoplasms) and relevant treatment strategies (superstructural pharmaceuticals). Thanks to this new point of view the most fundamental issue in physiology is the quest of how biological systems exert control on the self-assembly of their components and the most fundamental issue in pathology is the quest of how self-assembly of an undesired superstructure triggers a network of events that result in a particular disease state. Therefore, every disease (infectious or non-infectious) must have a superstructural disease agent (SDA). Sophisticated superstructures like bacteria and viruses are stable and long living and thus infectious but simpler SDAs are unstable and short living thus less infectious. Then we can see how diseases like sarcoidosis, currently classified as noninfectious, are indeed infectious. From this point of view, the fact that one viral infection is protective against a second viral infection can be seen as a superstructural drug that protects against a superstructural disease agent. So it becomes understandable how one opportunistic infection in a late-stage HIV-infected individual may cause deestablishment of HIV-infection in a long-term survivor.

Research paper thumbnail of The Impact of Self-Assembly in Medicine and Pharmacology

Current Pharmaceutical Analysis, Feb 1, 2006

Research paper thumbnail of Self-assembly-based Thermo-responsible Luminescent Organogels of Chromophoric L-glutamide-derived Lipids

Journal of Materials Research, Sep 1, 2005

Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their... more Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their photo-responsive properties were investigated in organic solution systems. By comparing their spectral behaviors, it was shown that organogels underwent a light blue to purple luminescence change, which was triggered by thermally induced monomeric-to-excimeric phase transition. This switching, based on self-assembly, is supposed to have special advantages in molecular electronics.

Research paper thumbnail of Possible effect of epinephrine in minimizing COVID-19 severity: a review

Journal of International Medical Research, Sep 1, 2020

Objective: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an as... more Objective: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. Methods: This paper presents a short literature review to suggest a new treatment modality for COVID-19. Results: COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. Conclusion: Application of epinephrine pulses with a specific amplitude may be considered an intervention to minimize the severity of COVID-19.

Research paper thumbnail of Temporal variations in COVID-19: an epidemiological discussion with a practical application

Journal of International Medical Research

ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) i... more ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) infection and mortality as a possible tool to monitor and control the spread of this disease.MethodsWe analyzed cyclicity and synchronicity in cases of COVID-19 infection and time series of deaths using Fourier transform, its inverse method, and statistical treatments. Epidemiological indices (e.g., case fatality rate) were used to quantify the observations in the time series. The possible causes of short-term variations are reviewed.ResultsWe observed that were both short-term and long-term variations in the COVID-19 time series. The short cycles were 7 days and synchronized among all countries. This periodicity is believed to be caused by weekly cycles in community social factors, combined with diagnostic and reporting cycles. This could also be related to virus–host–community dynamics.ConclusionThe observed synchronized weekly cycles could serve as herd defense by providing a form of s...

Research paper thumbnail of Short communication Dioctadecyl l-glutamide-derived lipid-grafted silica as a novel organic stationary phase for RP-HPLC

Research paper thumbnail of Possible effect of epinephrine in minimizing COVID-19 severity: a review

Journal of International Medical Research, 2020

Objective Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asy... more Objective Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. Methods This paper presents a short literature review to suggest a new treatment modality for COVID-19. Results COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. Conclusion Application of epinephrine pulses with a speci...

Research paper thumbnail of 1P-0310 Do Iranian students of health school really have low cardiovascular risk factors?

Atherosclerosis Supplements, 2003

Research paper thumbnail of The impact of supramolecular chemistry in medicine: Removing the border between infectious and non-infectious diseases

Research paper thumbnail of Self-assembly-based Thermo-responsible Luminescent Organogels of Chromophoric L-glutamide-derived Lipids

Journal of Materials Research, 2005

Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their... more Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their photo-responsive properties were investigated in organic solution systems. By comparing their spectral behaviors, it was shown that organogels underwent a light blue to purple luminescence change, which was triggered by thermally induced monomeric-to-excimeric phase transition. This switching, based on self-assembly, is supposed to have special advantages in molecular electronics.

Research paper thumbnail of Dioctadecyl l-glutamide-derived lipid-grafted silica as a novel organic stationary phase for RP-HPLC

Journal of Chromatography A, 2005

Dialkyl l-glutamide-derived lipids have been found to form supramolecular assemblies and to show ... more Dialkyl l-glutamide-derived lipids have been found to form supramolecular assemblies and to show specific properties based on their highly ordered structures in aqueous and organic media. To use these unique properties to create molecular recognition systems, dioctadecyl l-glutamide-derived lipid-grafted porous silica particles (Sil-DSG) were newly prepared and used as a stationary phase in reversed phase liquid chromatography. Compared with conventional ODS (octadecylated silica), the Sil-DSG column showed remarkably higher selectivity for polycyclic aromatic hydrocarbons (PAHs). Especially, Sil-DSG recognized the molecular linearity and planarity of PAHs. Suspension state 1 H NMR and 13 C CP/MAS-NMR spectroscopies showed that the alkyl chains on the Sil-DSG are in gauche form and their mobility is strongly restricted at room temperature. This paper discusses higher selectivity of Sil-DSG with a carbonyl-benzene interactions.

Research paper thumbnail of The Impact of Self-Assembly in Medicine and Pharmacology

Current Pharmaceutical Analysis, 2006

Research paper thumbnail of Conformational Effect of Silica-supported Poly(octadecyl acrylate) on Molecular-Shape Selectivity of Polycyclic Aromatic Hydrocarbons in RP-HPLC

Analytical Sciences, 2004

Poly(octadecyl acrylate) with a terminal reactive group was synthesized by radical telomerization... more Poly(octadecyl acrylate) with a terminal reactive group was synthesized by radical telomerization in various solvents. The polymers were grafted onto porous silica for use in RP-HPLC, and the molecular recognition ability was investigated along with the selectivity for the structural isomers of polycyclic aromatic hydrocarbons. The mechanism of selectivity was also investigated with differential scanning calorimetry and NMR spectroscopic observations.

Research paper thumbnail of Molecular Shape Selectivity through Multiple Carbonyl−π Interactions with Noncrystalline Solid Phase for RP-HPLC

Analytical Chemistry, 2005

Research paper thumbnail of Evaluation of microstructural features of a new polymeric organic stationary phase grafted on silica surface: A paradigm of characterization of HPLC-stationary phases by a combination of suspension-state 1H NMR and solid-state 13C-CP/MAS-NMR

Analytica Chimica Acta, 2005

Silica-supported poly(octadecylacrylate) (Sil-ODA n), polymeric octadecylsilyl silica (polymeric ... more Silica-supported poly(octadecylacrylate) (Sil-ODA n), polymeric octadecylsilyl silica (polymeric ODS), and monomeric octadecylsilyl silica (monomeric ODS) were studied by a combination of suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR to probe the mechanisms underlying their functions as stationary phases for RP-HPLC. Sil-ODA n , with a strong temperature dependent separation behaviour showed correspondent temperature dependent manifestations in both suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR experiments. With a gradual increase in temperature, intensity of proton signals (1 H NMR) of octadecyl moieties (mainly methylene groups) rose dramatically. This dramatic rise was at the same temperature of an endothermic peak detectable in its DSC thermogram indicating a relatively complete solid to liquid phase transition. In addition temperature dependencies of the ratio of trans to gauche conformed well to temperature dependencies of the separation factor between naphthacene and triphenylene (as a simple indicator of shape selectivity). Therefore NMR spectra of Sil-ODA n were used as a reference for ascertaining percentage of octadecyl moieties of liquid type mobility in the two other stationary phases. Using this method we determined percentage of liquid phase in polymeric ODS and monomeric ODS at various temperatures. We suggest a combination of suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR for structure-dynamic characterization of various kinds of hydrocarbon chains grafted onto the silica particles.

Research paper thumbnail of A new method for evaluation of the mobility of silica-grafted alkyl chains by suspension-state 1 H NMR

Canadian Journal of Chemistry, 2005

Although molecular mobility is usually probed by measurement of the T1 relaxation time, it is not... more Although molecular mobility is usually probed by measurement of the T1 relaxation time, it is not the case for methylene groups of grafted acyl chains because each methylene group has a different mobility and hence, a different T1 relaxation time depending on the distance from the junction between organic molecule and nonorganic particle. Therefore, we devised a very simple method that can semiquantitatively determine the extent of mobility in the grafted acyl chains. Silica-supported poly(octadecylacrylate) (Sil-ODAn), polymeric octadecylsilyl silica (polymeric ODS), and monomeric octadecylsilyl silica (monomeric ODS) were studied by comparing the intensity of NMR peaks from grafted molecules with the same amount of nongrafted molecules. In the case of Sil-ODAn, with a gradual increase in temperature, the intensity of the proton signals (1H NMR) of the octadecyl moieties (mainly methylene groups) rose dramatically. This dramatic rise was at the same temperature as that of an endoth...

Research paper thumbnail of Conformational Effect of Silica-supported Poly(octadecyl acrylate) on Molecular-Shape Selectivity of Polycyclic Aromatic Hydrocarbons in RP-HPLC

Analytical Sciences, Dec 1, 2004

Research paper thumbnail of Temporal variations in COVID-19: an epidemiological discussion with a practical application

Journal of International Medical Research, Aug 1, 2021

ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) i... more ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) infection and mortality as a possible tool to monitor and control the spread of this disease.MethodsWe analyzed cyclicity and synchronicity in cases of COVID-19 infection and time series of deaths using Fourier transform, its inverse method, and statistical treatments. Epidemiological indices (e.g., case fatality rate) were used to quantify the observations in the time series. The possible causes of short-term variations are reviewed.ResultsWe observed that were both short-term and long-term variations in the COVID-19 time series. The short cycles were 7 days and synchronized among all countries. This periodicity is believed to be caused by weekly cycles in community social factors, combined with diagnostic and reporting cycles. This could also be related to virus–host–community dynamics.ConclusionThe observed synchronized weekly cycles could serve as herd defense by providing a form of social distancing in time. The effect of such temporal distancing could be enhanced if combined with spatial distancing. Integrated spatiotemporal distancing is therefore recommended to optimize infection control strategies, taking into account the quiescent and active intervals of COVID-19.

Research paper thumbnail of The impact of supramolecular chemistry in medicine: Removing the border between infectious and non-infectious diseases

Medical Hypotheses, Dec 1, 2008

The concept, molecular self-assembly, has a profoundly novel effect on thoughts and efforts relat... more The concept, molecular self-assembly, has a profoundly novel effect on thoughts and efforts related to medicine and pharmacology. This new style of thinking calls for a range of new researches based on new predictions about disease mechanisms (especially autoimmune diseases, endocrinopathies, and neoplasms) and relevant treatment strategies (superstructural pharmaceuticals). Thanks to this new point of view the most fundamental issue in physiology is the quest of how biological systems exert control on the self-assembly of their components and the most fundamental issue in pathology is the quest of how self-assembly of an undesired superstructure triggers a network of events that result in a particular disease state. Therefore, every disease (infectious or non-infectious) must have a superstructural disease agent (SDA). Sophisticated superstructures like bacteria and viruses are stable and long living and thus infectious but simpler SDAs are unstable and short living thus less infectious. Then we can see how diseases like sarcoidosis, currently classified as noninfectious, are indeed infectious. From this point of view, the fact that one viral infection is protective against a second viral infection can be seen as a superstructural drug that protects against a superstructural disease agent. So it becomes understandable how one opportunistic infection in a late-stage HIV-infected individual may cause deestablishment of HIV-infection in a long-term survivor.

Research paper thumbnail of The Impact of Self-Assembly in Medicine and Pharmacology

Current Pharmaceutical Analysis, Feb 1, 2006

Research paper thumbnail of Self-assembly-based Thermo-responsible Luminescent Organogels of Chromophoric L-glutamide-derived Lipids

Journal of Materials Research, Sep 1, 2005

Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their... more Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their photo-responsive properties were investigated in organic solution systems. By comparing their spectral behaviors, it was shown that organogels underwent a light blue to purple luminescence change, which was triggered by thermally induced monomeric-to-excimeric phase transition. This switching, based on self-assembly, is supposed to have special advantages in molecular electronics.

Research paper thumbnail of Possible effect of epinephrine in minimizing COVID-19 severity: a review

Journal of International Medical Research, Sep 1, 2020

Objective: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an as... more Objective: Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. Methods: This paper presents a short literature review to suggest a new treatment modality for COVID-19. Results: COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. Conclusion: Application of epinephrine pulses with a specific amplitude may be considered an intervention to minimize the severity of COVID-19.

Research paper thumbnail of Temporal variations in COVID-19: an epidemiological discussion with a practical application

Journal of International Medical Research

ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) i... more ObjectiveWe aimed to characterize the temporal variation in coronavirus disease 2019 (COVID-19) infection and mortality as a possible tool to monitor and control the spread of this disease.MethodsWe analyzed cyclicity and synchronicity in cases of COVID-19 infection and time series of deaths using Fourier transform, its inverse method, and statistical treatments. Epidemiological indices (e.g., case fatality rate) were used to quantify the observations in the time series. The possible causes of short-term variations are reviewed.ResultsWe observed that were both short-term and long-term variations in the COVID-19 time series. The short cycles were 7 days and synchronized among all countries. This periodicity is believed to be caused by weekly cycles in community social factors, combined with diagnostic and reporting cycles. This could also be related to virus–host–community dynamics.ConclusionThe observed synchronized weekly cycles could serve as herd defense by providing a form of s...

Research paper thumbnail of Short communication Dioctadecyl l-glutamide-derived lipid-grafted silica as a novel organic stationary phase for RP-HPLC

Research paper thumbnail of Possible effect of epinephrine in minimizing COVID-19 severity: a review

Journal of International Medical Research, 2020

Objective Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asy... more Objective Coronavirus disease 2019 (COVID-19) shows a wide range of severity, ranging from an asymptomatic presentation to a severe illness requiring intensive care unit admission. Identification of a strategy to manage the severity of this disease will not only help to reduce its case fatality but also help to remove some of the burden from the already overwhelmed health care systems. While successful management of symptoms in general is important, identifying measures to modify the severity of the illness is a key factor in the fight against this pandemic. Methods This paper presents a short literature review to suggest a new treatment modality for COVID-19. Results COVID-19 is less severe and rarely fatal in children than in adults, which could be caused by greater fluctuations of plasma epinephrine in children. Our literature survey endorses this hypothesis according to both the epidemiological and immunological findings. Conclusion Application of epinephrine pulses with a speci...

Research paper thumbnail of 1P-0310 Do Iranian students of health school really have low cardiovascular risk factors?

Atherosclerosis Supplements, 2003

Research paper thumbnail of The impact of supramolecular chemistry in medicine: Removing the border between infectious and non-infectious diseases

Research paper thumbnail of Self-assembly-based Thermo-responsible Luminescent Organogels of Chromophoric L-glutamide-derived Lipids

Journal of Materials Research, 2005

Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their... more Three lipophilic L-glutamide derivatives with chromophoric head group were synthesized, and their photo-responsive properties were investigated in organic solution systems. By comparing their spectral behaviors, it was shown that organogels underwent a light blue to purple luminescence change, which was triggered by thermally induced monomeric-to-excimeric phase transition. This switching, based on self-assembly, is supposed to have special advantages in molecular electronics.

Research paper thumbnail of Dioctadecyl l-glutamide-derived lipid-grafted silica as a novel organic stationary phase for RP-HPLC

Journal of Chromatography A, 2005

Dialkyl l-glutamide-derived lipids have been found to form supramolecular assemblies and to show ... more Dialkyl l-glutamide-derived lipids have been found to form supramolecular assemblies and to show specific properties based on their highly ordered structures in aqueous and organic media. To use these unique properties to create molecular recognition systems, dioctadecyl l-glutamide-derived lipid-grafted porous silica particles (Sil-DSG) were newly prepared and used as a stationary phase in reversed phase liquid chromatography. Compared with conventional ODS (octadecylated silica), the Sil-DSG column showed remarkably higher selectivity for polycyclic aromatic hydrocarbons (PAHs). Especially, Sil-DSG recognized the molecular linearity and planarity of PAHs. Suspension state 1 H NMR and 13 C CP/MAS-NMR spectroscopies showed that the alkyl chains on the Sil-DSG are in gauche form and their mobility is strongly restricted at room temperature. This paper discusses higher selectivity of Sil-DSG with a carbonyl-benzene interactions.

Research paper thumbnail of The Impact of Self-Assembly in Medicine and Pharmacology

Current Pharmaceutical Analysis, 2006

Research paper thumbnail of Conformational Effect of Silica-supported Poly(octadecyl acrylate) on Molecular-Shape Selectivity of Polycyclic Aromatic Hydrocarbons in RP-HPLC

Analytical Sciences, 2004

Poly(octadecyl acrylate) with a terminal reactive group was synthesized by radical telomerization... more Poly(octadecyl acrylate) with a terminal reactive group was synthesized by radical telomerization in various solvents. The polymers were grafted onto porous silica for use in RP-HPLC, and the molecular recognition ability was investigated along with the selectivity for the structural isomers of polycyclic aromatic hydrocarbons. The mechanism of selectivity was also investigated with differential scanning calorimetry and NMR spectroscopic observations.

Research paper thumbnail of Molecular Shape Selectivity through Multiple Carbonyl−π Interactions with Noncrystalline Solid Phase for RP-HPLC

Analytical Chemistry, 2005

Research paper thumbnail of Evaluation of microstructural features of a new polymeric organic stationary phase grafted on silica surface: A paradigm of characterization of HPLC-stationary phases by a combination of suspension-state 1H NMR and solid-state 13C-CP/MAS-NMR

Analytica Chimica Acta, 2005

Silica-supported poly(octadecylacrylate) (Sil-ODA n), polymeric octadecylsilyl silica (polymeric ... more Silica-supported poly(octadecylacrylate) (Sil-ODA n), polymeric octadecylsilyl silica (polymeric ODS), and monomeric octadecylsilyl silica (monomeric ODS) were studied by a combination of suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR to probe the mechanisms underlying their functions as stationary phases for RP-HPLC. Sil-ODA n , with a strong temperature dependent separation behaviour showed correspondent temperature dependent manifestations in both suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR experiments. With a gradual increase in temperature, intensity of proton signals (1 H NMR) of octadecyl moieties (mainly methylene groups) rose dramatically. This dramatic rise was at the same temperature of an endothermic peak detectable in its DSC thermogram indicating a relatively complete solid to liquid phase transition. In addition temperature dependencies of the ratio of trans to gauche conformed well to temperature dependencies of the separation factor between naphthacene and triphenylene (as a simple indicator of shape selectivity). Therefore NMR spectra of Sil-ODA n were used as a reference for ascertaining percentage of octadecyl moieties of liquid type mobility in the two other stationary phases. Using this method we determined percentage of liquid phase in polymeric ODS and monomeric ODS at various temperatures. We suggest a combination of suspension-state 1 H NMR and solid-state 13 C CP/MAS-NMR for structure-dynamic characterization of various kinds of hydrocarbon chains grafted onto the silica particles.

Research paper thumbnail of A new method for evaluation of the mobility of silica-grafted alkyl chains by suspension-state 1 H NMR

Canadian Journal of Chemistry, 2005

Although molecular mobility is usually probed by measurement of the T1 relaxation time, it is not... more Although molecular mobility is usually probed by measurement of the T1 relaxation time, it is not the case for methylene groups of grafted acyl chains because each methylene group has a different mobility and hence, a different T1 relaxation time depending on the distance from the junction between organic molecule and nonorganic particle. Therefore, we devised a very simple method that can semiquantitatively determine the extent of mobility in the grafted acyl chains. Silica-supported poly(octadecylacrylate) (Sil-ODAn), polymeric octadecylsilyl silica (polymeric ODS), and monomeric octadecylsilyl silica (monomeric ODS) were studied by comparing the intensity of NMR peaks from grafted molecules with the same amount of nongrafted molecules. In the case of Sil-ODAn, with a gradual increase in temperature, the intensity of the proton signals (1H NMR) of the octadecyl moieties (mainly methylene groups) rose dramatically. This dramatic rise was at the same temperature as that of an endoth...