Thanh Pham - Academia.edu (original) (raw)
Papers by Thanh Pham
Historically, tuberculosis (TB) has left a scar as mankind's greatest infectious killer. With evi... more Historically, tuberculosis (TB) has left a scar as mankind's greatest infectious killer. With evidence of TB infection dating back nine millenia to a Neolithic Eastern Mediterranean settlement [1], this ancient disease meant almost certain death to those infected, a phenomenon spanning pre-antibiotic eras from the time of the Roman empire all the way to the beginning of the 20 th century. But with the advent of antibiotics starting around 80 years ago, TB then became a curable disease. It had no longer the deadly effectiveness as it did for ancient Roman and Victorian populations. As an effect, Mycobacterium tuberculosis, the causative agent of TB discovered by Robert Koch in 1882, finally faded out of the limelight.
Journal of virology, 2013
DNA-dependent activator of interferon regulatory factor (DAI) acts as a cytosolic B-form DNA sens... more DNA-dependent activator of interferon regulatory factor (DAI) acts as a cytosolic B-form DNA sensor that induces type I interferons. However, DAI is not required for DNA sensing in certain cell types due to redundancy of the DNA sensing system. Here, we investigated the effect of DAI on herpes simplex virus 1 (HSV-1) infection in HepG2 hepatocellular carcinoma cells. DAI transcription was induced after gamma interferon (IFN-␥) treatment or HSV-1 infection. HSV-1 replication was enhanced by DAI knockdown, and ectopic DAI expression repressed viral replication in a manner requiring the Z and D3 domains, but not the Z␣ domain. This activity of DAI was more prominent at low multiplicity of infection (MOI) and correlated with the reduced expression of viral immediate-early genes. Consistently, DAI repressed the activation of ICP0 promoter in reporter gene assays.
Biomacromolecules, Jan 10, 2014
Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. Howeve... more Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. However, the mechanical properties of synthetic spider silks spun from recombinant MaSp1 and MaSp2 proteins have yet to approach natural fibers, implying the natural spinning dope is missing critical factors. Here we report the discovery of novel molecular constituents within the spinning dope that are extruded into dragline silk. Protein studies of the liquid spinning dope from the major ampullate gland, coupled with the analysis of dragline silk fibers using mass spectrometry, demonstrate the presence of a new family of low-molecular-weight cysteine-rich proteins (CRPs) that colocalize with the MA fibroins. Expression of the CRP family members is linked to dragline silk production, specifically MaSp1 and MaSp2 mRNA synthesis. Biochemical data support that CRP molecules are secreted into the spinning dope and assembled into macromolecular complexes via disulfide bond linkages. Sequence analysis supports that CRP molecules share similarities to members that belong to the cystine slipknot superfamily, suggesting that these factors may have evolved to increase fiber toughness by serving as molecular hubs that dissipate large amounts of energy under stress. Collectively, our findings provide molecular details about the components of dragline silk, providing new insight that will advance materials development of synthetic spider silk for industrial applications.
The Journal of biological chemistry, Jan 29, 2013
Background: Bacterial pathogens use virulence proteins to inhibit the host innate immune system. ... more Background: Bacterial pathogens use virulence proteins to inhibit the host innate immune system. Results: The Escherichia coli O157:H7 NleH1 protein interacts with the host CRKL protein.
International Conference on Communications and Signal Processing, 2011
Multiple-input multiple-output (MIMO) repeater systems have been discussed in several published p... more Multiple-input multiple-output (MIMO) repeater systems have been discussed in several published papers. When a repeater has only one antenna element, the propagation environment is called keyhole. In this kind of scenario the achievable channel capacity and link quality are decreased. Another limit is when the number of the antenna elements of a repeater is larger than that of a MIMO transceiver, the channel capacity cannot be increased. In this paper, in order to obtain high channel capacity, the repeaters are distributed in series. We optimize the position of each repeater for upper bound of channel capacity with each number of repeaters, and the upper bound of channel capacity when the number of repeater is assumed to be infinite.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
In the present work, silicon nanowires were prepared by a thermal evaporation method. The evapora... more In the present work, silicon nanowires were prepared by a thermal evaporation method. The evaporating source was a mixture of silicon and carbon nanopowders. Surface morphology, structural characteristics and emission properties of the silicon nanowires were investigated by several techniques. The results showed that the obtained products have the shape of nanowires with diameters ranging from 30 to 120 nm and lengths from 300 to 400 nm. The x-ray diffraction (XRD) patterns confirmed the presence of crystalline silicon. Transmission electron microscope (TEM) images revealed the core-shell structure of the wires. In the photoluminescence (PL) spectra recorded at room temperature, only a broad emission band peaking at about 650 nm was observed. In addition to the red emission, two other bands centered at around 455 nm and 510 nm appeared when measured at low temperatures. The origin and emission mechanism of these bands are discussed.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
As-synthesized ZnS:Cu,Al nanocrystals with average size of 2-3 nm show abroad emission band peaki... more As-synthesized ZnS:Cu,Al nanocrystals with average size of 2-3 nm show abroad emission band peaking at 445 nm (blue) and a shoulder at around 540 nm (green). Annealing the nanocrystals in nitrogen gas results in a reduction in the intensity of the blue emission while enhancing the intensity of the green emission band. The maximum of the green emission is first redshifted to around 590 nm when the annealing temperature is increased to 400 • C, and later blueshifted to 564 and 500 nm for the samples annealed at 500 • C and 600 • C for 1 h, respectively. The lower phase-transition temperature (from zinc blende to wurtzite) and the donor-acceptor pair luminescence process in nanocrystals are discussed.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
Silicon nanowires were successfully synthesized by a thermal evaporation method. We have observed... more Silicon nanowires were successfully synthesized by a thermal evaporation method. We have observed a strong and broad emission band centered at 670 nm, which is attributed to the quantum confinement effect related to Si nanostructures embedded in the complex SiO x matrix. By fitting an experimental Raman spectrum, we confirm that the as-received wires possess crystalline silicon cores whose sizes were around 5 nm. Furthermore, the abnormal dependence of integral photoluminescence intensity on measured temperature was investigated.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2010
Silicon nanostructure-based light emitting devices (nc SiLED) have been fabricated using conventi... more Silicon nanostructure-based light emitting devices (nc SiLED) have been fabricated using conventional microelectronic technologies. The emissive layer composed of silicon and silicon dioxide was deposited by magnetron co-sputtering. Under forward bias, a broad electroluminescence (PL) spectrum in the range 450-900 nm was observed, peaking at around 705 nm. The effect of Si content in the active layer on the electrical and optical properties of these devices was measured and discussed.
Paddy and Water Environment, 2006
The Mekong River Basin (MRB) is the biggest basin in Monsoon Asia. About 80% of the agricultural ... more The Mekong River Basin (MRB) is the biggest basin in Monsoon Asia. About 80% of the agricultural lands, which occupy about 40% of the basin are rain-fed paddy rice area. Therefore, it is assumed that changes in rain-fed paddy rice production affect the total agricultural production to a great degree in the Mekong River Basin. While there are many factors affecting the productivity of rain-fed paddies, such as climate, water use, rice varieties, applications of manure, fertilizer and agro-chemicals, sowing date and other agronomic practices, this paper focuses on the relation between rainfall and yields of rain-fed paddies. Agricultural statistics and rainfall data were collected and analyzed for all 24 provinces in Cambodia for the years 2001 and 2002. Factors such as soil fertility and other natural conditions were removed by comparing the yield and rainfall in one province for different years. Special attention was given to the relation between yields of paddy in the wet season and rainfall, considering factors such as rice varieties, soil fertility, irrigation ratio and the ratio of area damaged by flood, drought, and insect. Although it is not easy to assess those impact factors on yields because they are organically interactive, the following results were obtained: (1) The ratio of high yielding varieties (HYV), soil fertility, and irrigation ratio among many factors that affect yields individually, especially if they are combined, (2) Total rainfall did not have a significant influence on rice yields even for the rain-fed paddies if it was over 700 mm in wet season, and one of the reasons for this would be that there exist supplementary water uses through small ponds and water ponding in local land depressions in and around paddies.
Topology and Its Applications, 2007
We give an example of a group action on Euclidean space for which each map in the action is compa... more We give an example of a group action on Euclidean space for which each map in the action is compactly supported, and such that the action is chaotic in the sense that it is topologically transitive and the set of points with finite orbit is dense. This resolves a conjecture of Naolekar and Sankaran.
Historically, tuberculosis (TB) has left a scar as mankind's greatest infectious killer. With evi... more Historically, tuberculosis (TB) has left a scar as mankind's greatest infectious killer. With evidence of TB infection dating back nine millenia to a Neolithic Eastern Mediterranean settlement [1], this ancient disease meant almost certain death to those infected, a phenomenon spanning pre-antibiotic eras from the time of the Roman empire all the way to the beginning of the 20 th century. But with the advent of antibiotics starting around 80 years ago, TB then became a curable disease. It had no longer the deadly effectiveness as it did for ancient Roman and Victorian populations. As an effect, Mycobacterium tuberculosis, the causative agent of TB discovered by Robert Koch in 1882, finally faded out of the limelight.
Journal of virology, 2013
DNA-dependent activator of interferon regulatory factor (DAI) acts as a cytosolic B-form DNA sens... more DNA-dependent activator of interferon regulatory factor (DAI) acts as a cytosolic B-form DNA sensor that induces type I interferons. However, DAI is not required for DNA sensing in certain cell types due to redundancy of the DNA sensing system. Here, we investigated the effect of DAI on herpes simplex virus 1 (HSV-1) infection in HepG2 hepatocellular carcinoma cells. DAI transcription was induced after gamma interferon (IFN-␥) treatment or HSV-1 infection. HSV-1 replication was enhanced by DAI knockdown, and ectopic DAI expression repressed viral replication in a manner requiring the Z and D3 domains, but not the Z␣ domain. This activity of DAI was more prominent at low multiplicity of infection (MOI) and correlated with the reduced expression of viral immediate-early genes. Consistently, DAI repressed the activation of ICP0 promoter in reporter gene assays.
Biomacromolecules, Jan 10, 2014
Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. Howeve... more Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. However, the mechanical properties of synthetic spider silks spun from recombinant MaSp1 and MaSp2 proteins have yet to approach natural fibers, implying the natural spinning dope is missing critical factors. Here we report the discovery of novel molecular constituents within the spinning dope that are extruded into dragline silk. Protein studies of the liquid spinning dope from the major ampullate gland, coupled with the analysis of dragline silk fibers using mass spectrometry, demonstrate the presence of a new family of low-molecular-weight cysteine-rich proteins (CRPs) that colocalize with the MA fibroins. Expression of the CRP family members is linked to dragline silk production, specifically MaSp1 and MaSp2 mRNA synthesis. Biochemical data support that CRP molecules are secreted into the spinning dope and assembled into macromolecular complexes via disulfide bond linkages. Sequence analysis supports that CRP molecules share similarities to members that belong to the cystine slipknot superfamily, suggesting that these factors may have evolved to increase fiber toughness by serving as molecular hubs that dissipate large amounts of energy under stress. Collectively, our findings provide molecular details about the components of dragline silk, providing new insight that will advance materials development of synthetic spider silk for industrial applications.
The Journal of biological chemistry, Jan 29, 2013
Background: Bacterial pathogens use virulence proteins to inhibit the host innate immune system. ... more Background: Bacterial pathogens use virulence proteins to inhibit the host innate immune system. Results: The Escherichia coli O157:H7 NleH1 protein interacts with the host CRKL protein.
International Conference on Communications and Signal Processing, 2011
Multiple-input multiple-output (MIMO) repeater systems have been discussed in several published p... more Multiple-input multiple-output (MIMO) repeater systems have been discussed in several published papers. When a repeater has only one antenna element, the propagation environment is called keyhole. In this kind of scenario the achievable channel capacity and link quality are decreased. Another limit is when the number of the antenna elements of a repeater is larger than that of a MIMO transceiver, the channel capacity cannot be increased. In this paper, in order to obtain high channel capacity, the repeaters are distributed in series. We optimize the position of each repeater for upper bound of channel capacity with each number of repeaters, and the upper bound of channel capacity when the number of repeater is assumed to be infinite.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
In the present work, silicon nanowires were prepared by a thermal evaporation method. The evapora... more In the present work, silicon nanowires were prepared by a thermal evaporation method. The evaporating source was a mixture of silicon and carbon nanopowders. Surface morphology, structural characteristics and emission properties of the silicon nanowires were investigated by several techniques. The results showed that the obtained products have the shape of nanowires with diameters ranging from 30 to 120 nm and lengths from 300 to 400 nm. The x-ray diffraction (XRD) patterns confirmed the presence of crystalline silicon. Transmission electron microscope (TEM) images revealed the core-shell structure of the wires. In the photoluminescence (PL) spectra recorded at room temperature, only a broad emission band peaking at about 650 nm was observed. In addition to the red emission, two other bands centered at around 455 nm and 510 nm appeared when measured at low temperatures. The origin and emission mechanism of these bands are discussed.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
As-synthesized ZnS:Cu,Al nanocrystals with average size of 2-3 nm show abroad emission band peaki... more As-synthesized ZnS:Cu,Al nanocrystals with average size of 2-3 nm show abroad emission band peaking at 445 nm (blue) and a shoulder at around 540 nm (green). Annealing the nanocrystals in nitrogen gas results in a reduction in the intensity of the blue emission while enhancing the intensity of the green emission band. The maximum of the green emission is first redshifted to around 590 nm when the annealing temperature is increased to 400 • C, and later blueshifted to 564 and 500 nm for the samples annealed at 500 • C and 600 • C for 1 h, respectively. The lower phase-transition temperature (from zinc blende to wurtzite) and the donor-acceptor pair luminescence process in nanocrystals are discussed.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2011
Silicon nanowires were successfully synthesized by a thermal evaporation method. We have observed... more Silicon nanowires were successfully synthesized by a thermal evaporation method. We have observed a strong and broad emission band centered at 670 nm, which is attributed to the quantum confinement effect related to Si nanostructures embedded in the complex SiO x matrix. By fitting an experimental Raman spectrum, we confirm that the as-received wires possess crystalline silicon cores whose sizes were around 5 nm. Furthermore, the abnormal dependence of integral photoluminescence intensity on measured temperature was investigated.
Advances in Natural Sciences: Nanoscience and Nanotechnology, 2010
Silicon nanostructure-based light emitting devices (nc SiLED) have been fabricated using conventi... more Silicon nanostructure-based light emitting devices (nc SiLED) have been fabricated using conventional microelectronic technologies. The emissive layer composed of silicon and silicon dioxide was deposited by magnetron co-sputtering. Under forward bias, a broad electroluminescence (PL) spectrum in the range 450-900 nm was observed, peaking at around 705 nm. The effect of Si content in the active layer on the electrical and optical properties of these devices was measured and discussed.
Paddy and Water Environment, 2006
The Mekong River Basin (MRB) is the biggest basin in Monsoon Asia. About 80% of the agricultural ... more The Mekong River Basin (MRB) is the biggest basin in Monsoon Asia. About 80% of the agricultural lands, which occupy about 40% of the basin are rain-fed paddy rice area. Therefore, it is assumed that changes in rain-fed paddy rice production affect the total agricultural production to a great degree in the Mekong River Basin. While there are many factors affecting the productivity of rain-fed paddies, such as climate, water use, rice varieties, applications of manure, fertilizer and agro-chemicals, sowing date and other agronomic practices, this paper focuses on the relation between rainfall and yields of rain-fed paddies. Agricultural statistics and rainfall data were collected and analyzed for all 24 provinces in Cambodia for the years 2001 and 2002. Factors such as soil fertility and other natural conditions were removed by comparing the yield and rainfall in one province for different years. Special attention was given to the relation between yields of paddy in the wet season and rainfall, considering factors such as rice varieties, soil fertility, irrigation ratio and the ratio of area damaged by flood, drought, and insect. Although it is not easy to assess those impact factors on yields because they are organically interactive, the following results were obtained: (1) The ratio of high yielding varieties (HYV), soil fertility, and irrigation ratio among many factors that affect yields individually, especially if they are combined, (2) Total rainfall did not have a significant influence on rice yields even for the rain-fed paddies if it was over 700 mm in wet season, and one of the reasons for this would be that there exist supplementary water uses through small ponds and water ponding in local land depressions in and around paddies.
Topology and Its Applications, 2007
We give an example of a group action on Euclidean space for which each map in the action is compa... more We give an example of a group action on Euclidean space for which each map in the action is compactly supported, and such that the action is chaotic in the sense that it is topologically transitive and the set of points with finite orbit is dense. This resolves a conjecture of Naolekar and Sankaran.