Allicin, an antioxidant, is known for providing garlic with its unique fragrance and taste, as well as for its antimicrobial properties. Black garlic, a fermented form of garlic, contains higher levels of antioxidants...Allicin, an antioxidant, is known for providing garlic with its unique fragrance and taste, as well as for its antimicrobial properties. Black garlic, a fermented form of garlic, contains higher levels of antioxidants than fresh garlic. Antioxidants play a vital role in alleviating cellular stress during viral infections. Viral infections result in oxidative stress through the production of reactive oxidative species (ROS). A prolonged state of oxidative stress can result in cell death, DNA damage, and disease progression. In this study, black garlic extract (BGE) is evaluated for its ability to mitigate cytopathic effects and oxidative stress caused by herpes simplex virus-2 (HSV-2) infections in vitro. Antiviral assays were performed to determine the percent of viral inhibition resulting from treatment with the BGE. ROS-Glo<sup>TM</sup> H<sub>2</sub>O<sub>2</sub> assays were then completed to measure the post-infection ROS levels of BGE-treated virus and cells. The results thus far suggest that BGE may inhibit viral infection and decrease levels of oxidative stress.展开更多
Herpes simplex virus-1 (HSV-1) remains a leading cause of viral disease worldwide and is spread by direct contact with infected lesions. There is no vaccine against HSV-1 infections and there remains a need to identif...Herpes simplex virus-1 (HSV-1) remains a leading cause of viral disease worldwide and is spread by direct contact with infected lesions. There is no vaccine against HSV-1 infections and there remains a need to identify therapeutics that could reduce the spread. In this study various hispolon compounds were analyzed to determine their antiviral potential against HSV-1 infections in cultured Vero cells. To determine the effects on infectivity and possible mechanisms of inhibition, the following assays were conducted. In vitro cytotoxicity assays were conducted to determine the effect of the compounds on cell viability and the maximum non-cytotoxic concentrations. Antiviral assays measured cell viability, percent inhibition of infection following treatment with the compounds, and the effect on the viral infection cycle. These effects were visualized using inverted light and fluorescent microscopy. Of the 24 hispolons tested, only hispolon pyrazole-1 (HISP-1) demonstrated antiviral effects. HISP-1 was demonstrated to effect early stages in HSV-1 infection in cultured Vero cells (attachment, penetration, and post-penetration). In silico modeling analyses were conducted to analyze the interactions between HISP-1 and viral glycoprotein D (gD). HISP-1 is safe at concentrations tested and is effective in inhibiting infection of HSV-1 in cultured cells. HISP-1 has potential for therapeutic use as an antiviral against HSV-1 infection, could work in synergy with other antivirals that work be a different modality, and could be developed as a component of a topical agent to reduce the spread of HSV-1 infections.展开更多
A numerical procedure for analyzing the temperature distribution in a hollow axisymmetric cylinder, made of functionally gradient material (FGM), was investigated. Based on the thermal elasticity theory and the arbi...A numerical procedure for analyzing the temperature distribution in a hollow axisymmetric cylinder, made of functionally gradient material (FGM), was investigated. Based on the thermal elasticity theory and the arbitrary difference precise integration (ADPI) method, temperature distribution through the FGM cylinder in the ring section under a transient-state temperature field was developed and presented. A genetic algorithm (GA) was applied to the thermal stress optimal design of an FGM hollow cylinder, and as a result, the minimum thermal stress distribution in the FGM cylinder was obtained. A corresponding numerical procedure regarding to a ceramic-metal FGM cylinder was perforrned. and the comnutational results were discussed.展开更多
In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT...In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT) model. The model was tested at the Juntanghu watershed on the northern slope of the Tian Shan Mountains, Xinjiang,China. We compared the performances of temperature-index method and energy balanced method in SWAT model by taking Juntanghu river basin as an application example(as the simulation experiment was conducted in Juntanghu River, we call the energy balanced method as SWAT-JTH). The results suggest that the SWAT snowmelt model had overall Nash-Sutcliffe efficiency(NSE) coefficients ranging from 0.61 to 0.85 while the physical based approach had NSE coefficients ranging from 0.58 to0.69. Overall, on monthly scale, the SWAT model provides better results than that from the SWAT-JTH model. However, results generated from both methods seem to be fairly close at a daily scale. Thestructure of the temperature-index method is simple and produces reasonable simulation results if the parameters are well within empirical ranges. Although the data requirement for the energy balance method in current observation is difficult to meet and the existence of uncertainty is associated with the experimental approaches of physical processes, the SWAT-JTH model still produced a reasonably high NSE. We conclude that using temperature-index methods to simulate the snowmelt process is sufficient, but the energy balance-based model is still a good choice to simulate extreme weather conditions especially when the required data input for the model is acquired.展开更多
This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons (ΣPAH) in the surface sediments of China’s marginal seas. BC content ranges from <0.10...This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons (ΣPAH) in the surface sediments of China’s marginal seas. BC content ranges from <0.10 to 2.45 mg/g dw (grams dry weight) in the sediments studied, and varied among the different coastal regions. The Bohai Bay sediments had the highest BC contents (average 2.18 mg/g dw), which comprises a significant fraction (27%–41%) of the total organic carbon (TOC) preserved in the sediments. In comparison, BC in the surface sediments of the North Yellow Sea, Jiaozhou Bay, East China Sea and the South China Sea is less abundant and accounted for an average of 6%, 8%, 14% and 5%, respectively, of the sedimentary organic carbon pool. The concentration of ΣPAH in the surface sediments ranges from 41 to 3 667 ng/g dw and showed large spatial variations among the sampling sites of different costal regions. The Bohai Bay has the highest ΣPAH values, ranging from 79 to 3 667 ng/g dw. This reflects the high anthropogenically contaminated nature of the sediments in the bay. BC is positively correlated to TOC but a strong correlation is not found between BC and ΣPAH in the surface sediments studied, suggesting that BC and PAHs preserved in the sediments are derived from different sources and controlled by different biogeochemical processes. Our study suggests that the abundance of BC preserved in the sediments could represent a significant sink pool of carbon cycling in China’s marginal seas.展开更多
This study focuses on the comparison of the Uniform Building Code (UBC) 1997 and International Building Code (IBC) 2003 in relation to the seismic design and analysis of special steel moment resisting frame buildi...This study focuses on the comparison of the Uniform Building Code (UBC) 1997 and International Building Code (IBC) 2003 in relation to the seismic design and analysis of special steel moment resisting frame buildings (SMRF). This paper formulates a numerical study of a steel SMRF building, studied in four different situations, namely: as an office building in San Francisco; as an office building in Sacramento; as an essential facility in San Francisco, and as an essential facility in Sacramento. The analytical results of the model buildings are then compared and analyzed taking note of any significant differences. This case study explores variations in the results obtained using the two codes, particularly the design base shear and drift ratios as they relate to different locations and occupancy use. This study also proves that IBC 2003 is more stringent for the redundancy factor under design category E for the SMRF building, and drift limits for essential facilities.展开更多
This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport...This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport and sedimentation in the bay. The modeling results show that the two regions are located within the residual current vortexes. Results from the particle-tracking model indicate that the trace metals released from the land sources enter the regions and take a relatively long residence time in the vortexes. The sediment radionuclide data indicates that the two regions experienced continuous and high sedimentation, and trace metals are prone to deposit in the regions. The correlations among trace metals, residual currents and radionuclides data suggest that the tides are the governing factor controlling the distributions of the trace metals in the bay. The consistence among these results also supports the reliabilities of the numerical simulation results of water and trace metal transport in this study.展开更多
Green tea leaves contain many polyphenolic compounds such as (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)epigallocatechin-3-gallate (EGCG). These polyphenol compounds have...Green tea leaves contain many polyphenolic compounds such as (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)epigallocatechin-3-gallate (EGCG). These polyphenol compounds have been implicated to have distinct properties that combat the harmful effects of cell proliferation. They contain certain anti-viral and antibacterial properties that inhibit growth. In this study, 1% green tea and modified lipophilic green tea polyphenols (GTP and LTP) were used in combination with the most commonly prescribed antibiotics to study their effects on gram-positive, gram-negative, and acid-fast bacteria. The results indicated that 1% GTP and 1% LTP provided different synergistic effects on several antibiotics in various bacteria. It was found that 1% GTP works the best synergistically against Enterobacter aerogenes, making the resistant strain susceptible to 8 out of 12 antibiotics used. 1% LTP worked the best on Escherichia coli and was able to convert 7 antibiotic resistant categories to susceptible. In addition, 1% LTP was also able to inhibit the growth of Serratia marcescens synergistically with 3 antibiotics. These results suggest that 1% GTP and 1% LTP provide beneficial effects on selected antibiotics against microbial growth and are able to reverse the antibiotic resistance to susceptible. Green tea polyphenols could serve as natural alternatives to combat against antibiotic resistance pathogens.展开更多
Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipo...Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipophilic properties. The chemical modification of EGCG-S increased its lipid solubility. Herpes simplex virus-1 (HSV-1), a member of the family Herpesviridae, and Alphaherpesvirinae subfamily is a leading cause of human viral diseases in the United States. In this study, 25 μM, 50 μM, 75 μM, and 100 μM of EGCG and EGCG-S were used to carry out cytotoxicity, cell viability and cell proliferation assays to determine the maximum non-cytotoxic concentrations on cultured A549 cells. The results suggested that 75 μM of EGCG and EGCG-S is the appropriate concentration to further study the effect on the infection of HSV-1 in A549 cells. Infectivity, antiviral, and inverted microscopy assays were performed to study the effects of EGCG and EGCG-S on HSV-1 infection. An antiviral assay was performed using luminescence and it indicated that EGCG-S treated HSV-1 showed up to 90% inhibition. Confocal microscopy images further supported the inhibitory effects of 75 μM EGCG-S on HSV-1 infection in A549 cells. The long-term goal of this research is to use EGCG-S as a possible novel topical therapeutic treatment to limit the spread of HSV-1 infections.展开更多
Endospores have the ability to withstand extreme temperature, desiccation, ultraviolet radiation and chemicals which make them a threat to the food and healthcare industry. Green tea polyphenols (GTP), contain anti-mi...Endospores have the ability to withstand extreme temperature, desiccation, ultraviolet radiation and chemicals which make them a threat to the food and healthcare industry. Green tea polyphenols (GTP), contain anti-microbial and anti-spore properties but not stable. In this study, two modified lipophilic green tea polyphenols, epigallocatechin-3-gallate-sterate (EGCG-S) and crude lipophilic green tea polyphenols (LTP), were used to compare their anti-spore effect with EGCG and crude GTP. Purified endospores from Bacillus cereus (B. cereus), B. megaterium and B. subtilis were treated with 1% or 5% of four tea polyphenols. Log reduction showed colony forming units (CFU) reduced significantly in all treated samples, ranging from 1.27 to 4.31 with no survivals (CFU = 0) in four samples (P < 0.05). Average percentage of inhibition for these poly-phenols treatment ranged from 91.68% to 100%. The EGCG-S and LTP have equal or better anti-spore activities compared with EGCG and GTP. EGCG-S and LTP were further used to carry out time course study on B. cereus. The results indicated that 15 min of treatment of 1% and 5% LTP and EGCG-S are able to inhibit 98.7% to 100% of germination. Transmission and scanning electron microscopy studies showed that EGCG-S caused surface disruption and damaged spores structural integrity. EGCG-S and LTP are stable anti-spore agents may aid in preventing food and beverage spoilage caused by spore-forming bacteria as well as preventing contamination in the medical industry.展开更多
A semi-supervised vector machine is a relatively new learning method using both labeled and unlabeled data in classifi- cation. Since the objective function of the model for an unstrained semi-supervised vector machin...A semi-supervised vector machine is a relatively new learning method using both labeled and unlabeled data in classifi- cation. Since the objective function of the model for an unstrained semi-supervised vector machine is not smooth, many fast opti- mization algorithms cannot be applied to solve the model. In order to overcome the difficulty of dealing with non-smooth objective functions, new methods that can solve the semi-supervised vector machine with desired classification accuracy are in great demand. A quintic spline function with three-times differentiability at the ori- gin is constructed by a general three-moment method, which can be used to approximate the symmetric hinge loss function. The approximate accuracy of the quintic spiine function is estimated. Moreover, a quintic spline smooth semi-support vector machine is obtained and the convergence accuracy of the smooth model to the non-smooth one is analyzed. Three experiments are performed to test the efficiency of the model. The experimental results show that the new model outperforms other smooth models, in terms of classification performance. Furthermore, the new model is not sensitive to the increasing number of the labeled samples, which means that the new model is more efficient.展开更多
A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrumen...A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.展开更多
The purpose of this study was to investigate the effect of curcumin-treated Herpes simplex virus-1 (HSV-1) and Herpes simplex virus-2 (HSV-2) virions in cultured Vero cells. Previous studies have indicated that curcum...The purpose of this study was to investigate the effect of curcumin-treated Herpes simplex virus-1 (HSV-1) and Herpes simplex virus-2 (HSV-2) virions in cultured Vero cells. Previous studies have indicated that curcumin, a polyphenol extracted from the plant Curcuma longa, has demonstrated antiviral properties against a variety of viruses. After establishing the maximum non-cytotoxic concentrations of curcumin on Vero cells, HSV-1 and HSV-2 virions were treated with varying concentrations of curcumin. The effect on infectivity was determined by antiviral assays, using WST-1, plaque assays, adsorption and penetration assays. Treating HSV-1 and HSV-2 viruses with curcumin, at a concentration of 30 μM, reduces the production of infectious HSV-1 and HSV-2 virions in cultured Vero cells by interfering with the adsorption process. These results support the potential of curcumin to be used as a therapeutic agent to reduce the transmission of HSV-1 and HSV-2.展开更多
Gout is a form of inflammatory arthritis characterized by sharp pain and severe swelling that often causes severe physical disability. Gout is caused by the chronic elevation of uric acid levels in the blood and is kn...Gout is a form of inflammatory arthritis characterized by sharp pain and severe swelling that often causes severe physical disability. Gout is caused by the chronic elevation of uric acid levels in the blood and is known as the disease of kings due to its strong association with a diet rich in fructose and beer. Recent studies suggest that a high uric acid concentration is the result of a dynamical process that highlights the interactions between leptin production, insulin resistance, low muscle mass and a diet rich in fructose. Once individuals develop hyperuricemia, reach a high uric acid concentration in excess of 7 mg/dL for men and 6 mg/dL for women, they become susceptible to developing gout. We propose a novel dynamic system to analyze and determine the connections between a diet involving different levels of fructose (in both adult men and women in the U.S.) and the concentration of uric acid in the blood. Our model simulations suggest that adult males under a diet containing levels of fructose stimulating a 0.5 uric acid growth rate, could develop hyperuricemia after around 10,000 days, while it only takes women about 5000 days with a diet stimulating a 0.4 growth rate.展开更多
文摘Allicin, an antioxidant, is known for providing garlic with its unique fragrance and taste, as well as for its antimicrobial properties. Black garlic, a fermented form of garlic, contains higher levels of antioxidants than fresh garlic. Antioxidants play a vital role in alleviating cellular stress during viral infections. Viral infections result in oxidative stress through the production of reactive oxidative species (ROS). A prolonged state of oxidative stress can result in cell death, DNA damage, and disease progression. In this study, black garlic extract (BGE) is evaluated for its ability to mitigate cytopathic effects and oxidative stress caused by herpes simplex virus-2 (HSV-2) infections in vitro. Antiviral assays were performed to determine the percent of viral inhibition resulting from treatment with the BGE. ROS-Glo<sup>TM</sup> H<sub>2</sub>O<sub>2</sub> assays were then completed to measure the post-infection ROS levels of BGE-treated virus and cells. The results thus far suggest that BGE may inhibit viral infection and decrease levels of oxidative stress.
文摘Herpes simplex virus-1 (HSV-1) remains a leading cause of viral disease worldwide and is spread by direct contact with infected lesions. There is no vaccine against HSV-1 infections and there remains a need to identify therapeutics that could reduce the spread. In this study various hispolon compounds were analyzed to determine their antiviral potential against HSV-1 infections in cultured Vero cells. To determine the effects on infectivity and possible mechanisms of inhibition, the following assays were conducted. In vitro cytotoxicity assays were conducted to determine the effect of the compounds on cell viability and the maximum non-cytotoxic concentrations. Antiviral assays measured cell viability, percent inhibition of infection following treatment with the compounds, and the effect on the viral infection cycle. These effects were visualized using inverted light and fluorescent microscopy. Of the 24 hispolons tested, only hispolon pyrazole-1 (HISP-1) demonstrated antiviral effects. HISP-1 was demonstrated to effect early stages in HSV-1 infection in cultured Vero cells (attachment, penetration, and post-penetration). In silico modeling analyses were conducted to analyze the interactions between HISP-1 and viral glycoprotein D (gD). HISP-1 is safe at concentrations tested and is effective in inhibiting infection of HSV-1 in cultured cells. HISP-1 has potential for therapeutic use as an antiviral against HSV-1 infection, could work in synergy with other antivirals that work be a different modality, and could be developed as a component of a topical agent to reduce the spread of HSV-1 infections.
文摘A numerical procedure for analyzing the temperature distribution in a hollow axisymmetric cylinder, made of functionally gradient material (FGM), was investigated. Based on the thermal elasticity theory and the arbitrary difference precise integration (ADPI) method, temperature distribution through the FGM cylinder in the ring section under a transient-state temperature field was developed and presented. A genetic algorithm (GA) was applied to the thermal stress optimal design of an FGM hollow cylinder, and as a result, the minimum thermal stress distribution in the FGM cylinder was obtained. A corresponding numerical procedure regarding to a ceramic-metal FGM cylinder was perforrned. and the comnutational results were discussed.
基金financially supported by the Ministry of Water Resources (MWR) public sector research and special funds-the most stringent in arid zone water resources management key technologies (201301103)National Nature Science Foundation of China (NSFC) under Grant No. 41130641, 41201025+1 种基金Ministry of Education Key Laboratory of Eco-Oasis Open Topic-Moisture change in Central Asia and its influence on precipitation in Xinjang Province (XJDX0201-2013-07)the Tianshan Scholar Start-up Fund provided by Xinjiang University
文摘In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT) model. The model was tested at the Juntanghu watershed on the northern slope of the Tian Shan Mountains, Xinjiang,China. We compared the performances of temperature-index method and energy balanced method in SWAT model by taking Juntanghu river basin as an application example(as the simulation experiment was conducted in Juntanghu River, we call the energy balanced method as SWAT-JTH). The results suggest that the SWAT snowmelt model had overall Nash-Sutcliffe efficiency(NSE) coefficients ranging from 0.61 to 0.85 while the physical based approach had NSE coefficients ranging from 0.58 to0.69. Overall, on monthly scale, the SWAT model provides better results than that from the SWAT-JTH model. However, results generated from both methods seem to be fairly close at a daily scale. Thestructure of the temperature-index method is simple and produces reasonable simulation results if the parameters are well within empirical ranges. Although the data requirement for the energy balance method in current observation is difficult to meet and the existence of uncertainty is associated with the experimental approaches of physical processes, the SWAT-JTH model still produced a reasonably high NSE. We conclude that using temperature-index methods to simulate the snowmelt process is sufficient, but the energy balance-based model is still a good choice to simulate extreme weather conditions especially when the required data input for the model is acquired.
基金Supported by the National Natural Science Foundation of China (No. 40476038 and 40576039)
文摘This study investigates the distribution of black carbon (BC) and its correlation with total polycyclic aromatic hydrocarbons (ΣPAH) in the surface sediments of China’s marginal seas. BC content ranges from <0.10 to 2.45 mg/g dw (grams dry weight) in the sediments studied, and varied among the different coastal regions. The Bohai Bay sediments had the highest BC contents (average 2.18 mg/g dw), which comprises a significant fraction (27%–41%) of the total organic carbon (TOC) preserved in the sediments. In comparison, BC in the surface sediments of the North Yellow Sea, Jiaozhou Bay, East China Sea and the South China Sea is less abundant and accounted for an average of 6%, 8%, 14% and 5%, respectively, of the sedimentary organic carbon pool. The concentration of ΣPAH in the surface sediments ranges from 41 to 3 667 ng/g dw and showed large spatial variations among the sampling sites of different costal regions. The Bohai Bay has the highest ΣPAH values, ranging from 79 to 3 667 ng/g dw. This reflects the high anthropogenically contaminated nature of the sediments in the bay. BC is positively correlated to TOC but a strong correlation is not found between BC and ΣPAH in the surface sediments studied, suggesting that BC and PAHs preserved in the sediments are derived from different sources and controlled by different biogeochemical processes. Our study suggests that the abundance of BC preserved in the sediments could represent a significant sink pool of carbon cycling in China’s marginal seas.
基金Rearch Grant from the School of Engineering,San Francisco State University
文摘This study focuses on the comparison of the Uniform Building Code (UBC) 1997 and International Building Code (IBC) 2003 in relation to the seismic design and analysis of special steel moment resisting frame buildings (SMRF). This paper formulates a numerical study of a steel SMRF building, studied in four different situations, namely: as an office building in San Francisco; as an office building in Sacramento; as an essential facility in San Francisco, and as an essential facility in Sacramento. The analytical results of the model buildings are then compared and analyzed taking note of any significant differences. This case study explores variations in the results obtained using the two codes, particularly the design base shear and drift ratios as they relate to different locations and occupancy use. This study also proves that IBC 2003 is more stringent for the redundancy factor under design category E for the SMRF building, and drift limits for essential facilities.
基金financially supported in part by the Key Program of Tianjin Natural Science Foundation(Grant No.16JCZDJC39400)the National Key Research and Development Program of China(Grant No.2016YFC0502204)+1 种基金the National Natural Science Foundation of China(Grant No.21501042)China Scholarship Council
文摘This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport and sedimentation in the bay. The modeling results show that the two regions are located within the residual current vortexes. Results from the particle-tracking model indicate that the trace metals released from the land sources enter the regions and take a relatively long residence time in the vortexes. The sediment radionuclide data indicates that the two regions experienced continuous and high sedimentation, and trace metals are prone to deposit in the regions. The correlations among trace metals, residual currents and radionuclides data suggest that the tides are the governing factor controlling the distributions of the trace metals in the bay. The consistence among these results also supports the reliabilities of the numerical simulation results of water and trace metal transport in this study.
文摘Green tea leaves contain many polyphenolic compounds such as (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)epigallocatechin-3-gallate (EGCG). These polyphenol compounds have been implicated to have distinct properties that combat the harmful effects of cell proliferation. They contain certain anti-viral and antibacterial properties that inhibit growth. In this study, 1% green tea and modified lipophilic green tea polyphenols (GTP and LTP) were used in combination with the most commonly prescribed antibiotics to study their effects on gram-positive, gram-negative, and acid-fast bacteria. The results indicated that 1% GTP and 1% LTP provided different synergistic effects on several antibiotics in various bacteria. It was found that 1% GTP works the best synergistically against Enterobacter aerogenes, making the resistant strain susceptible to 8 out of 12 antibiotics used. 1% LTP worked the best on Escherichia coli and was able to convert 7 antibiotic resistant categories to susceptible. In addition, 1% LTP was also able to inhibit the growth of Serratia marcescens synergistically with 3 antibiotics. These results suggest that 1% GTP and 1% LTP provide beneficial effects on selected antibiotics against microbial growth and are able to reverse the antibiotic resistance to susceptible. Green tea polyphenols could serve as natural alternatives to combat against antibiotic resistance pathogens.
文摘Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipophilic properties. The chemical modification of EGCG-S increased its lipid solubility. Herpes simplex virus-1 (HSV-1), a member of the family Herpesviridae, and Alphaherpesvirinae subfamily is a leading cause of human viral diseases in the United States. In this study, 25 μM, 50 μM, 75 μM, and 100 μM of EGCG and EGCG-S were used to carry out cytotoxicity, cell viability and cell proliferation assays to determine the maximum non-cytotoxic concentrations on cultured A549 cells. The results suggested that 75 μM of EGCG and EGCG-S is the appropriate concentration to further study the effect on the infection of HSV-1 in A549 cells. Infectivity, antiviral, and inverted microscopy assays were performed to study the effects of EGCG and EGCG-S on HSV-1 infection. An antiviral assay was performed using luminescence and it indicated that EGCG-S treated HSV-1 showed up to 90% inhibition. Confocal microscopy images further supported the inhibitory effects of 75 μM EGCG-S on HSV-1 infection in A549 cells. The long-term goal of this research is to use EGCG-S as a possible novel topical therapeutic treatment to limit the spread of HSV-1 infections.
文摘Endospores have the ability to withstand extreme temperature, desiccation, ultraviolet radiation and chemicals which make them a threat to the food and healthcare industry. Green tea polyphenols (GTP), contain anti-microbial and anti-spore properties but not stable. In this study, two modified lipophilic green tea polyphenols, epigallocatechin-3-gallate-sterate (EGCG-S) and crude lipophilic green tea polyphenols (LTP), were used to compare their anti-spore effect with EGCG and crude GTP. Purified endospores from Bacillus cereus (B. cereus), B. megaterium and B. subtilis were treated with 1% or 5% of four tea polyphenols. Log reduction showed colony forming units (CFU) reduced significantly in all treated samples, ranging from 1.27 to 4.31 with no survivals (CFU = 0) in four samples (P < 0.05). Average percentage of inhibition for these poly-phenols treatment ranged from 91.68% to 100%. The EGCG-S and LTP have equal or better anti-spore activities compared with EGCG and GTP. EGCG-S and LTP were further used to carry out time course study on B. cereus. The results indicated that 15 min of treatment of 1% and 5% LTP and EGCG-S are able to inhibit 98.7% to 100% of germination. Transmission and scanning electron microscopy studies showed that EGCG-S caused surface disruption and damaged spores structural integrity. EGCG-S and LTP are stable anti-spore agents may aid in preventing food and beverage spoilage caused by spore-forming bacteria as well as preventing contamination in the medical industry.
基金supported by the Fundamental Research Funds for University of Science and Technology Beijing(FRF-BR-12-021)
文摘A semi-supervised vector machine is a relatively new learning method using both labeled and unlabeled data in classifi- cation. Since the objective function of the model for an unstrained semi-supervised vector machine is not smooth, many fast opti- mization algorithms cannot be applied to solve the model. In order to overcome the difficulty of dealing with non-smooth objective functions, new methods that can solve the semi-supervised vector machine with desired classification accuracy are in great demand. A quintic spline function with three-times differentiability at the ori- gin is constructed by a general three-moment method, which can be used to approximate the symmetric hinge loss function. The approximate accuracy of the quintic spiine function is estimated. Moreover, a quintic spline smooth semi-support vector machine is obtained and the convergence accuracy of the smooth model to the non-smooth one is analyzed. Three experiments are performed to test the efficiency of the model. The experimental results show that the new model outperforms other smooth models, in terms of classification performance. Furthermore, the new model is not sensitive to the increasing number of the labeled samples, which means that the new model is more efficient.
基金Project(51178321)supported by the National Natural Science Foundation of ChinaProject(2012ZX07403-001)supported by the National Science and Technology Major Project,ChinaProject(20120072110050)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.
文摘The purpose of this study was to investigate the effect of curcumin-treated Herpes simplex virus-1 (HSV-1) and Herpes simplex virus-2 (HSV-2) virions in cultured Vero cells. Previous studies have indicated that curcumin, a polyphenol extracted from the plant Curcuma longa, has demonstrated antiviral properties against a variety of viruses. After establishing the maximum non-cytotoxic concentrations of curcumin on Vero cells, HSV-1 and HSV-2 virions were treated with varying concentrations of curcumin. The effect on infectivity was determined by antiviral assays, using WST-1, plaque assays, adsorption and penetration assays. Treating HSV-1 and HSV-2 viruses with curcumin, at a concentration of 30 μM, reduces the production of infectious HSV-1 and HSV-2 virions in cultured Vero cells by interfering with the adsorption process. These results support the potential of curcumin to be used as a therapeutic agent to reduce the transmission of HSV-1 and HSV-2.
文摘Gout is a form of inflammatory arthritis characterized by sharp pain and severe swelling that often causes severe physical disability. Gout is caused by the chronic elevation of uric acid levels in the blood and is known as the disease of kings due to its strong association with a diet rich in fructose and beer. Recent studies suggest that a high uric acid concentration is the result of a dynamical process that highlights the interactions between leptin production, insulin resistance, low muscle mass and a diet rich in fructose. Once individuals develop hyperuricemia, reach a high uric acid concentration in excess of 7 mg/dL for men and 6 mg/dL for women, they become susceptible to developing gout. We propose a novel dynamic system to analyze and determine the connections between a diet involving different levels of fructose (in both adult men and women in the U.S.) and the concentration of uric acid in the blood. Our model simulations suggest that adult males under a diet containing levels of fructose stimulating a 0.5 uric acid growth rate, could develop hyperuricemia after around 10,000 days, while it only takes women about 5000 days with a diet stimulating a 0.4 growth rate.