Jung Suh - Academia.edu (original) (raw)

Papers by Jung Suh

Chemistry and Physics of Lipids, 2015

A new technique for quantifying sphingosine phosphate lyase activity in biological samples is des... more A new technique for quantifying sphingosine phosphate lyase activity in biological samples is described. In this procedure, 2-hydrazinoquinoline is used to convert (2E)-hexadecenal into the corresponding hydrazone derivative to improve ionization efficiency and selectivity of detection. Combined utilization of liquid chromatographic separation and multiple reaction monitoring-mass spectrometry allows for simultaneous quantification of the substrate S1P and product (2E)-hexadecenal. Incorporation of (2E)- d5-hexadecenal as an internal standard improves detection accuracy and precision. A simple one-step derivatization procedure eliminates the need for further extractions. Limits of quantification for (2E)-hexadecenal and sphingosine-1-phosphate are 100 and 50fmol, respectively. The assay displays a wide dynamic detection range useful for detection of low basal sphingosine phosphate lyase activity in wild type cells, SPL-overexpressing cell lines, and wild type mouse tissues. Compared to current methods, the capacity for simultaneous detection of sphingosine-1-phosphate and (2E)-hexadecenal greatly improves the accuracy of results and shows excellent sensitivity and specificity for sphingosine phosphate lyase activity detection.

Chemistry & biology, Jan 17, 2014

Signaling through the Hippo pathway controls major aspects of cell growth and proliferation. Focu... more Signaling through the Hippo pathway controls major aspects of cell growth and proliferation. Focusing on the metabolic consequences of Hippo signaling, Mulvihill and colleagues in this issue of Chemistry & Biology employ a large scale, integrative approach and uncover downstream reorganization of cellular metabolism when the effector TAZ is upregulated, identifying new connections to lipid metabolism.

Emergency Radiology, 2007

Clinical manifestations and computed tomography (CT) findings of Fitz-Hugh-Curtis syndrome (FHCS)... more Clinical manifestations and computed tomography (CT) findings of Fitz-Hugh-Curtis syndrome (FHCS) are relatively well stabilized as right upper quadrant abdominal pain and hepatic capsular enhancement because of perihepatitis associated with pelvic inflammatory disease caused by N. gonorrhoeae and C. trachomatis. We encountered three patients with serial FHCS associated with pelvic inflammatory disease, who visited the emergency room with right upper quadrant abdominal pain. Abdominal CT revealed hepatic capsular or pericapsular enhancement along the anterior surface of the liver on the arterial phase. Recently, multi-detector CT has evolved as the first-line imaging modality of acute abdomen at the emergency room; we reemphasized the importance of the CT findings of this syndrome for differential diagnosis of right upper quadrant abdominal pain in sexually active young women. Physicians at the emergency room acknowledge the syndrome and should perform dynamic abdominopelvic CT including the arterial phase.

Synthetic Metals, 2001

Well-ordered Co nanowire arrays formed on the porous anodic aluminum oxide (AAO) templates prepar... more Well-ordered Co nanowire arrays formed on the porous anodic aluminum oxide (AAO) templates prepared by a two-step anodization technique have been used in the fabrication of well-aligned carbon nanotubes. Designed Co nanowire arrays can be made by ...

Physical Review Letters, 1994

Volume 72, Number 26 PHYSICAL REVIEW LETTERS 27 June 1994 Photon Scanning Tunneling Microscopy Im... more Volume 72, Number 26 PHYSICAL REVIEW LETTERS 27 June 1994 Photon Scanning Tunneling Microscopy Images of Optical Excitations of Fractal Metal Colloid Clusters ...

The Journal of Physical Chemistry C, 2009

ABSTRACT

The Journal of Physical Chemistry C, 2010

The Journal of Physical Chemistry B, 1998

The surface-enhanced Raman scattering spectra and the photochemistry of 1,10-phenanthroline (phen... more The surface-enhanced Raman scattering spectra and the photochemistry of 1,10-phenanthroline (phen) adsorbed on silver colloid were studied using a flow cell. Phen adsorbed on fresh colloid is found to undergo almost no photochemistry while the same molecule adsorbed on aged colloid appears to photodecompose to a species in which the C-N ring bond in one or both of the heterocycles is broken to produce a CdN moiety that binds to the silver surface. The contrast in the behavior of the two colloids is attributed to the differing bonding geometries of the adsorbate in the two cases. In the fresh colloid phen appears to bind with its C 2 axis normal to the local surface while on the aged colloid the molecule seems to bind flat on the surface. This difference in bonding strategy is ascribed to the existence of many surface defects on the surface of the fresh colloid that are ideal sites for bidentate chelation. These defects presumably significantly decrease in number as the surface heals with time. The photoproduct which forms upon irradiating phen adsorbed on aged colloid is subsequently observed to photodesorb at a rate significantly less rapid than that of the photodecomposition reaction. Both reactions are found to be one-photon processes; hence, the large photoreaction cross section in the visible is likely due to a metal-to-molecule charge-transfer transition.

The Journal of Physical Chemistry B, 2000

ABSTRACT

Synthetic Metals, 2004

We have developed a method to fabricate tube-in-tubes that are relatively long and made in all th... more We have developed a method to fabricate tube-in-tubes that are relatively long and made in all the pores of porous anodic aluminum oxide (AAO) nano-templates. Relatively a very small amount of Co was deposited in the pores of AAO templates prepared without doing a voltage drop at the end of anodization, and then etched in NaOH solution. This caused the

Sensors and Actuators B: Chemical, 2009

We have developed a simple and inexpensive method to fabricate carbon nanotube-based chemical sen... more We have developed a simple and inexpensive method to fabricate carbon nanotube-based chemical sensors by fabricating a horizontally aligned carbon nanotube film on a titanium/gold-coated glass plate using electrophoresis and fissure formation techniques. The sensors exhibited low noise and thus high sensitivity to the NH 3 and NO 2 molecules and the response times were relatively short. They were completely recovered within 40 s when a dc voltage of 5 V was applied for less than 30 s. The fabrication processes do not require any expensive equipment like e-beam lithographs. They are relatively simple and low-cost, and the sensors themselves are mass-producible.

Pediatric Radiology, 1998

Occupational and Environmental Medicine, 2001

To evaluate possible health effects related to work with hazardous materials as measured by end o... more To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years. Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials. During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01). Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians.

Nano Letters, 2006

Horizontally aligned carbon nanotube (CNT) field emitters, which strongly adhere to the substrate... more Horizontally aligned carbon nanotube (CNT) field emitters, which strongly adhere to the substrate and show good field emission properties, were fabricated by electrophoresis deposition and fissure formation techniques. A thin film of CNTs was deposited on a substrate, by electrophoresis, from an aqueous mixture of CNT and detergent, and then the detergent was deposited also by electropholysis. CNTs with a clean surface were exposed in the fissures produced by firing. The field emission was increased significantly due to the additional deposition of the detergent. When the CNTs were cut by increasing the firing time, the field emission increased significantly, while their stability decreased considerably. Our method does not require any further treatment for field emission.

Langmuir, 2006

Carbon nanotubes (CNTs)-mediated self-assembly of metal (Au and Ag) nanoparticles at the liquid/l... more Carbon nanotubes (CNTs)-mediated self-assembly of metal (Au and Ag) nanoparticles at the liquid/liquid interface in the form of a stable nanocomposite film is reported. The metallic luster results from the electronic coupling of nanoparticles, suggesting the formation of closely packed nanoparticle thin films. The interfacial film could be transferred to mica substrates and carbon-coated transmission electron microscopy (TEM) grids. The transferred films were very stable for a prolonged time. The samples were characterized by UV-vis spectroscopy, scanning electron microscopy (SEM), TEM, and X-ray photoelectron spectroscopy (XPS). SEM and TEM results show that the films formed at the liquid/liquid interface are indeed composite materials consisting of CNTs and nanoparticles. XPS measurements further indicate the presence of the interaction between nanoparticles and CNTs.

Journal of Raman Spectroscopy, 2009

We have fabricated silver nanorod arrays by electrodepositing the nanorods evenly in the shallow ... more We have fabricated silver nanorod arrays by electrodepositing the nanorods evenly in the shallow pores of porous anodic aluminum oxide (AAO) templates. The diameter and length were 28 and 44 nm, respectively. The maxima of the transverse and longitudinal modes of the surface plasmon were near 417 and 511 nm, respectively. A good surface-enhanced Raman scattering (SERS) spectrum was observed by excitation with the 514.5-nm laser line. The SERS intensity increased almost linearly upon malachite green isothiocyanate adsorption on the tips of the silver nanorods as the concentration of the mother solutions increased. Our results show that silver nanorods fabricated on AAO templates could be used as an SERS substrate for quantitative analyses.

Journal of Raman Spectroscopy, 1999

The amount of photoproduct of phthalazine adsorbed on silver surfaces was examined by observing S... more The amount of photoproduct of phthalazine adsorbed on silver surfaces was examined by observing SERS spectra. Some of the phthalazine adsorbed on silver surface did not photoreact even with prolonged irradiation and the relative amount of photoproduct was larger on irradiation ...

Journal of Raman Spectroscopy, 2001

ABSTRACT

Journal of Neurosurgery, 1987

A series of 210 patients with facial fractures sufficiently severe to require cranial computerize... more A series of 210 patients with facial fractures sufficiently severe to require cranial computerized tomography (CT) to evaluate suspected closed-head injury (CHI) was studied. The injuries were separated into five grades of severity based on neurological examination, including cranial CT. The injuries were also grouped into three categories based on facial regional involvement, using chi-square contingency table analysis. The data demonstrated that patients with upper facial fractures were at greatest risk for serious CHI. Injuries to both the mandibular and the midfacial regions with no upper facial involvement more frequently resulted in mild CHI with a modest likelihood of no neurological deficits. Trauma to only the mandibular region or to only the midfacial region was least likely to involve CHI.

Journal of Hepatology, 2004

Differently from that caused by other hepatotropic viruses, chronic HCV infection associates with... more Differently from that caused by other hepatotropic viruses, chronic HCV infection associates with a number of lymphoproliferative disorders of the B cell compartment, such as auto-antibody production, cryoglobulinemia and lymphomas. In the present study we show that multimeric CD81engagement, by the soluble combination of the non-neutralizing anti-CD81 mAb MG81 with either the recombinant HCV envelope protein 2 (HCV-E2), or the neutralizing mAb MG81/NA, triggers a BcR-independent activation signal sufficient to induce polyclonal proliferation and maturation of naïve B cells, as well as differentiation of memory B lymphocytes into plasma-blasts. Interestingly, when analyzed immediately after purification, B lymphocytes from chronically HCV-, but not HBV-infected patients, displayed an increased expression of activation markers and of the chemokine receptor CXCR3, with a relatively higher expression of these molecules on the naïve rather than on the memory B cell subset. The activated phenotype was turned off in patients achieving viral clearance after combined therapy. Taken together, these results strongly suggest that BcR-independent, multimeric interactions between HCV-E2 and CD81 can also occur in vivo and concur to perturb B cell homeostasis.

Chemistry and Physics of Lipids, 2015

A new technique for quantifying sphingosine phosphate lyase activity in biological samples is des... more A new technique for quantifying sphingosine phosphate lyase activity in biological samples is described. In this procedure, 2-hydrazinoquinoline is used to convert (2E)-hexadecenal into the corresponding hydrazone derivative to improve ionization efficiency and selectivity of detection. Combined utilization of liquid chromatographic separation and multiple reaction monitoring-mass spectrometry allows for simultaneous quantification of the substrate S1P and product (2E)-hexadecenal. Incorporation of (2E)- d5-hexadecenal as an internal standard improves detection accuracy and precision. A simple one-step derivatization procedure eliminates the need for further extractions. Limits of quantification for (2E)-hexadecenal and sphingosine-1-phosphate are 100 and 50fmol, respectively. The assay displays a wide dynamic detection range useful for detection of low basal sphingosine phosphate lyase activity in wild type cells, SPL-overexpressing cell lines, and wild type mouse tissues. Compared to current methods, the capacity for simultaneous detection of sphingosine-1-phosphate and (2E)-hexadecenal greatly improves the accuracy of results and shows excellent sensitivity and specificity for sphingosine phosphate lyase activity detection.

Chemistry & biology, Jan 17, 2014

Signaling through the Hippo pathway controls major aspects of cell growth and proliferation. Focu... more Signaling through the Hippo pathway controls major aspects of cell growth and proliferation. Focusing on the metabolic consequences of Hippo signaling, Mulvihill and colleagues in this issue of Chemistry & Biology employ a large scale, integrative approach and uncover downstream reorganization of cellular metabolism when the effector TAZ is upregulated, identifying new connections to lipid metabolism.

Emergency Radiology, 2007

Clinical manifestations and computed tomography (CT) findings of Fitz-Hugh-Curtis syndrome (FHCS)... more Clinical manifestations and computed tomography (CT) findings of Fitz-Hugh-Curtis syndrome (FHCS) are relatively well stabilized as right upper quadrant abdominal pain and hepatic capsular enhancement because of perihepatitis associated with pelvic inflammatory disease caused by N. gonorrhoeae and C. trachomatis. We encountered three patients with serial FHCS associated with pelvic inflammatory disease, who visited the emergency room with right upper quadrant abdominal pain. Abdominal CT revealed hepatic capsular or pericapsular enhancement along the anterior surface of the liver on the arterial phase. Recently, multi-detector CT has evolved as the first-line imaging modality of acute abdomen at the emergency room; we reemphasized the importance of the CT findings of this syndrome for differential diagnosis of right upper quadrant abdominal pain in sexually active young women. Physicians at the emergency room acknowledge the syndrome and should perform dynamic abdominopelvic CT including the arterial phase.

Synthetic Metals, 2001

Well-ordered Co nanowire arrays formed on the porous anodic aluminum oxide (AAO) templates prepar... more Well-ordered Co nanowire arrays formed on the porous anodic aluminum oxide (AAO) templates prepared by a two-step anodization technique have been used in the fabrication of well-aligned carbon nanotubes. Designed Co nanowire arrays can be made by ...

Physical Review Letters, 1994

Volume 72, Number 26 PHYSICAL REVIEW LETTERS 27 June 1994 Photon Scanning Tunneling Microscopy Im... more Volume 72, Number 26 PHYSICAL REVIEW LETTERS 27 June 1994 Photon Scanning Tunneling Microscopy Images of Optical Excitations of Fractal Metal Colloid Clusters ...

The Journal of Physical Chemistry C, 2009

ABSTRACT

The Journal of Physical Chemistry C, 2010

The Journal of Physical Chemistry B, 1998

The surface-enhanced Raman scattering spectra and the photochemistry of 1,10-phenanthroline (phen... more The surface-enhanced Raman scattering spectra and the photochemistry of 1,10-phenanthroline (phen) adsorbed on silver colloid were studied using a flow cell. Phen adsorbed on fresh colloid is found to undergo almost no photochemistry while the same molecule adsorbed on aged colloid appears to photodecompose to a species in which the C-N ring bond in one or both of the heterocycles is broken to produce a CdN moiety that binds to the silver surface. The contrast in the behavior of the two colloids is attributed to the differing bonding geometries of the adsorbate in the two cases. In the fresh colloid phen appears to bind with its C 2 axis normal to the local surface while on the aged colloid the molecule seems to bind flat on the surface. This difference in bonding strategy is ascribed to the existence of many surface defects on the surface of the fresh colloid that are ideal sites for bidentate chelation. These defects presumably significantly decrease in number as the surface heals with time. The photoproduct which forms upon irradiating phen adsorbed on aged colloid is subsequently observed to photodesorb at a rate significantly less rapid than that of the photodecomposition reaction. Both reactions are found to be one-photon processes; hence, the large photoreaction cross section in the visible is likely due to a metal-to-molecule charge-transfer transition.

The Journal of Physical Chemistry B, 2000

ABSTRACT

Synthetic Metals, 2004

We have developed a method to fabricate tube-in-tubes that are relatively long and made in all th... more We have developed a method to fabricate tube-in-tubes that are relatively long and made in all the pores of porous anodic aluminum oxide (AAO) nano-templates. Relatively a very small amount of Co was deposited in the pores of AAO templates prepared without doing a voltage drop at the end of anodization, and then etched in NaOH solution. This caused the

Sensors and Actuators B: Chemical, 2009

We have developed a simple and inexpensive method to fabricate carbon nanotube-based chemical sen... more We have developed a simple and inexpensive method to fabricate carbon nanotube-based chemical sensors by fabricating a horizontally aligned carbon nanotube film on a titanium/gold-coated glass plate using electrophoresis and fissure formation techniques. The sensors exhibited low noise and thus high sensitivity to the NH 3 and NO 2 molecules and the response times were relatively short. They were completely recovered within 40 s when a dc voltage of 5 V was applied for less than 30 s. The fabrication processes do not require any expensive equipment like e-beam lithographs. They are relatively simple and low-cost, and the sensors themselves are mass-producible.

Pediatric Radiology, 1998

Occupational and Environmental Medicine, 2001

To evaluate possible health effects related to work with hazardous materials as measured by end o... more To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years. Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials. During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01). Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians.

Nano Letters, 2006

Horizontally aligned carbon nanotube (CNT) field emitters, which strongly adhere to the substrate... more Horizontally aligned carbon nanotube (CNT) field emitters, which strongly adhere to the substrate and show good field emission properties, were fabricated by electrophoresis deposition and fissure formation techniques. A thin film of CNTs was deposited on a substrate, by electrophoresis, from an aqueous mixture of CNT and detergent, and then the detergent was deposited also by electropholysis. CNTs with a clean surface were exposed in the fissures produced by firing. The field emission was increased significantly due to the additional deposition of the detergent. When the CNTs were cut by increasing the firing time, the field emission increased significantly, while their stability decreased considerably. Our method does not require any further treatment for field emission.

Langmuir, 2006

Carbon nanotubes (CNTs)-mediated self-assembly of metal (Au and Ag) nanoparticles at the liquid/l... more Carbon nanotubes (CNTs)-mediated self-assembly of metal (Au and Ag) nanoparticles at the liquid/liquid interface in the form of a stable nanocomposite film is reported. The metallic luster results from the electronic coupling of nanoparticles, suggesting the formation of closely packed nanoparticle thin films. The interfacial film could be transferred to mica substrates and carbon-coated transmission electron microscopy (TEM) grids. The transferred films were very stable for a prolonged time. The samples were characterized by UV-vis spectroscopy, scanning electron microscopy (SEM), TEM, and X-ray photoelectron spectroscopy (XPS). SEM and TEM results show that the films formed at the liquid/liquid interface are indeed composite materials consisting of CNTs and nanoparticles. XPS measurements further indicate the presence of the interaction between nanoparticles and CNTs.

Journal of Raman Spectroscopy, 2009

We have fabricated silver nanorod arrays by electrodepositing the nanorods evenly in the shallow ... more We have fabricated silver nanorod arrays by electrodepositing the nanorods evenly in the shallow pores of porous anodic aluminum oxide (AAO) templates. The diameter and length were 28 and 44 nm, respectively. The maxima of the transverse and longitudinal modes of the surface plasmon were near 417 and 511 nm, respectively. A good surface-enhanced Raman scattering (SERS) spectrum was observed by excitation with the 514.5-nm laser line. The SERS intensity increased almost linearly upon malachite green isothiocyanate adsorption on the tips of the silver nanorods as the concentration of the mother solutions increased. Our results show that silver nanorods fabricated on AAO templates could be used as an SERS substrate for quantitative analyses.

Journal of Raman Spectroscopy, 1999

The amount of photoproduct of phthalazine adsorbed on silver surfaces was examined by observing S... more The amount of photoproduct of phthalazine adsorbed on silver surfaces was examined by observing SERS spectra. Some of the phthalazine adsorbed on silver surface did not photoreact even with prolonged irradiation and the relative amount of photoproduct was larger on irradiation ...

Journal of Raman Spectroscopy, 2001

ABSTRACT

Journal of Neurosurgery, 1987

A series of 210 patients with facial fractures sufficiently severe to require cranial computerize... more A series of 210 patients with facial fractures sufficiently severe to require cranial computerized tomography (CT) to evaluate suspected closed-head injury (CHI) was studied. The injuries were separated into five grades of severity based on neurological examination, including cranial CT. The injuries were also grouped into three categories based on facial regional involvement, using chi-square contingency table analysis. The data demonstrated that patients with upper facial fractures were at greatest risk for serious CHI. Injuries to both the mandibular and the midfacial regions with no upper facial involvement more frequently resulted in mild CHI with a modest likelihood of no neurological deficits. Trauma to only the mandibular region or to only the midfacial region was least likely to involve CHI.

Journal of Hepatology, 2004

Differently from that caused by other hepatotropic viruses, chronic HCV infection associates with... more Differently from that caused by other hepatotropic viruses, chronic HCV infection associates with a number of lymphoproliferative disorders of the B cell compartment, such as auto-antibody production, cryoglobulinemia and lymphomas. In the present study we show that multimeric CD81engagement, by the soluble combination of the non-neutralizing anti-CD81 mAb MG81 with either the recombinant HCV envelope protein 2 (HCV-E2), or the neutralizing mAb MG81/NA, triggers a BcR-independent activation signal sufficient to induce polyclonal proliferation and maturation of naïve B cells, as well as differentiation of memory B lymphocytes into plasma-blasts. Interestingly, when analyzed immediately after purification, B lymphocytes from chronically HCV-, but not HBV-infected patients, displayed an increased expression of activation markers and of the chemokine receptor CXCR3, with a relatively higher expression of these molecules on the naïve rather than on the memory B cell subset. The activated phenotype was turned off in patients achieving viral clearance after combined therapy. Taken together, these results strongly suggest that BcR-independent, multimeric interactions between HCV-E2 and CD81 can also occur in vivo and concur to perturb B cell homeostasis.