Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN...Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN suspension was prepared by high-pressurehomogenization technique, and then mixed with carbomer gel matrix to get SLN gel. The morphology,particle size with polydispersi-ty index (PI) and zeta potential were examined by atomic forcemicroscopy (AFM) and photon correlation spectroscopy (PCS). The entrapment efficiency, stability andin vitro drug release were also studied. The transdermal drug delivery through porcine ear skin wasevaluated using modified Franz diffusion cells. Results The SLN had a spherical shape with theaverage size of (95.5 - 186.2) nm, the zeta potential of (-26.3- -15.7) mV and the entrapmentefficiency of 67.4%-90.3% for different TAA encapsulated compounds. TAA-SLN carbomer gel had goodstability, the release profile in vitro fitted Higuchi equation. In comparison with conventionalhydrogels, TAA-SLN carbomer gel resulted in higher drug permeation amount and drug deposition withinporcine ear skin after 24 h penetration experiment. Conclusion TAA-SLN carbomer gel is preparedwith stable physicochemical properties. The release profile and improved drug permeation into skinmake it be a promising vehicle for transdermal drug delivery.展开更多
AIM: To evaluate how proximal colon polyps interpreted as hyperplastic polyps in 2001 would be interpreted by expert pathologists in 2007.METHODS: ≥ 5 mm in interpreted pathologists 2007 by 3 GI Forty consecutive p...AIM: To evaluate how proximal colon polyps interpreted as hyperplastic polyps in 2001 would be interpreted by expert pathologists in 2007.METHODS: ≥ 5 mm in interpreted pathologists 2007 by 3 GI Forty consecutive proximal colon polyps size, removed in 2001, and originally as hyperplastic polyps by general at Indiana University, were reviewed in pathologists.CONCLUSION: Many polyps interpreted as hyperplastic in 2001 were considered sessile serrated lesions by GI pathologists in 2007, but there is substantial inter-observer variation amongst GI pathologists.展开更多
This study examined the spatiotemporal dynamics of colored dissolved organic matter (CDOM) and spectral slope (S), and further to analyze its sources in three productive water supplies (Eagle Creek, Geist and Mor...This study examined the spatiotemporal dynamics of colored dissolved organic matter (CDOM) and spectral slope (S), and further to analyze its sources in three productive water supplies (Eagle Creek, Geist and Morse reservoirs) from Indiana, USA. The re- sults showed that he absorption coefficient aCDOM(440) ranged from 0.37 m-1 to 3.93 m-1 with an average of 1.89 ± 0.76 m-1 (±SD) for the aggregated dataset, and S varied from 0.0048 nm -1 to 0.0239 nm-1 with an average of 0.0108 ±0.0040 nmI. A significant relation- ship between S and aCDOM(440) can be fitted with a power equation (S = 0.013 × aCDOM(440)-0.42, R2 = 0.612), excluding data from Geist Reservoir during high flow (12 April 2010) and the Morse Reservoir on 25 June 2010 due to a T-storm achieves even higher determina- tion coefficient (R2 = 0.842). Correlation analysis indicated that aCDOM(440) has strong association with inorganic suspended matter (ISM) concentration (0.231 〈 R2 〈 0.786) for each of the field surveys, and this trend followed the aggregated datasets (R2 = 0.447, p 〈 0.001). In contrast, chlorophyll-a was only correlated with aCDOM(440) in summer and autumn (0.081 〈 R2 〈 0.763), indicating that CDOM is mainly from terrigenous sources in early spring and that phytoplankton contributed during the algal blooming season. The S value was used to characterize CDOM origin. The results indicate that the CDOM source is mainly controlled by hydrological varia- tions, while phytoplankton originated organic matter also closely linked with CDOM dynamics in three productive reservoirs.展开更多
The flowability of five kinds of microencapsulation powders,with differentβ-carotene contents and by two alternative particle-forming technologies i.e.spray-drying and starch-catching beadlet technology,was meas- ure...The flowability of five kinds of microencapsulation powders,with differentβ-carotene contents and by two alternative particle-forming technologies i.e.spray-drying and starch-catching beadlet technology,was meas- ured.The actual flow properties of the five powders were compared based on bin-flow test,and three flow indexes (Hausner ratio,repose angle and flow index)were measured.It was found that the repose angle is the most suitable index to reflect the flowability of these powders for the particle properties would not be altered due to compaction or tapping during the measuring process.Particle size and particle size distribution play most important roles in the flowability of these granular materials,which was also influenced by other factors like shape,surface texture,sur- face roughness,etc.Microcapsules with wall material of gelatin and a layer of modified starch absorbed on the sur- face showed excellent flowabilities and good mechanical properties,and they are favorable for tabletting to supply β-carotene.展开更多
The heat transfer enhancement(HTE) in tubular heat exchangers fitted with vortex-generator(VG) inserts is experimentally investigated. The studied four parameters and ranges are: winglets-pitch ratio(1.33, 2.67, and 4...The heat transfer enhancement(HTE) in tubular heat exchangers fitted with vortex-generator(VG) inserts is experimentally investigated. The studied four parameters and ranges are: winglets-pitch ratio(1.33, 2.67, and 4),winglets-length ratio(0.33, 0.67, and 1), winglets-width ratio(0.2, 0.4, and 0.6), and Reynolds number(5200to 12200). The testing fluids are the water and Cu–water nanofluid at the volumetric fraction of 0.2%. The results obtained on HTE, pressure drop, and performance evaluation criterion(PEC) are compared with those for water in a smooth tube. It is found that the VG inserts with lower winglets-pitch ratio and higher winglets-length/width ratios present higher values of HTE and pressure drop. Over the range studied, the maximum PEC of 1.83 is detected with the Cu–water nanofluid inside the tube equipped with a VG insert at the winglets-width ratio of0.6 for the maximum Reynolds number, when the heat transfer rate and pressure drop are 1.24 times and 2.03 times of those in the smooth tube. Generalized regression equations of the Nusselt number, friction factor, and PEC are presented for the tubular heat exchangers with the VG inserts for both water and Cu–water nanofluid.It is concluded that the main advantage of the VG inserts is their simple fabrication and considerable performance, particularly at higher Reynolds number.展开更多
A Pr-doped TiO2-NTs/SnO2-Sb electrode was prepared by a simple method, cyclic voltarnmetry (CV). The methyl orange (MO)aqueous solution was selected as a simulated wastewater. The ordered microstructural TiO2-NTs ...A Pr-doped TiO2-NTs/SnO2-Sb electrode was prepared by a simple method, cyclic voltarnmetry (CV). The methyl orange (MO)aqueous solution was selected as a simulated wastewater. The ordered microstructural TiO2-NTs substrate was synthesized by an electrochemical method to obtain large specific surface area and high space utilization. The phase structure, electrode surface morphology and electrochemical properties of electrodes were characterized by XRD, SEM and electrochemical technology, respectively. The results showed that praseo- dymium oxide was successfully doped into the SnOz-Sb film by CV method. Due to the doped Pr, the oxygen evo- lution potential increased from 2.25 V to 2.40 V. The degradation of MO was investigated by UV-vis. The Ct/C0(φ) was studied as a function to obtain the optimal parameters, such as the amount of doped Pr, current density and initial dye concentration. In addition, the degradation process followed pseudo-first-order reaction kinetics and the rate constant was 0.099 3 min-1. The result indicated that the introduction of Pr reduced the formation of oxygen vacancies or enhanced the formation of adsorbed hydroxyl radical groups on the surface, thus leading to better activity and stability.展开更多
Isoproterenol (ISPR) is an important catecholamine‐based drug that is widely used in the treatment of heart disease. However, overdose of this drug is very dangerous to the human body. In this study, a new sensor b...Isoproterenol (ISPR) is an important catecholamine‐based drug that is widely used in the treatment of heart disease. However, overdose of this drug is very dangerous to the human body. In this study, a new sensor based on a pyrogallol red modified‐multiwalled carbon nanotube paste electrode (PGRMMWCNTPE) was prepared and used for high sensitivity determination of ISPR in aqueous solution. Electrocatalytic oxidation of ISPR at the PGRMMWCNTPE was investigated by chronoam‐perometry, cyclic voltammetry, and square‐wave voltammetry. The values of the catalytic rate con‐stant, electron transfer coefficient, and diffusion coefficient for ISPR oxidation were then calculated using voltammetric data. A linear calibration curve was constructed for ISPR concentration in the range 0.8–570μmol/L with a detection limit of 0.47μmol/L ISPR. The sensor was then applied to the determination of ISPR in urine and drug samples with satisfactory results.展开更多
Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecul...Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecules as electrochemical intercalators. Here unimolecular hairpin oligonucleotides were self-assembled onto Au electrode surface and elongation on solid phase was carried out to double strand oligonucleotides with transcription factor NF-r,13 binding site. Gold nanoparticle-catalyzed Ag deposition was detected by anodic stripping voltammetry (ASV) for NF-kB binding. It was indicated that this method for sequence specific DNA binding protein detection shows pronounced specificity, sensitivity and we can find application in transcription regulation research, open reading frame characterization and functional gene inspection by this method.展开更多
Women contribution to all the four pillars of food security (food availability, accessibility, utilization, and sovereignty) has been well established in Ghana and many sub-Saharan African countries. However, the is...Women contribution to all the four pillars of food security (food availability, accessibility, utilization, and sovereignty) has been well established in Ghana and many sub-Saharan African countries. However, the issue of sustainability of their contribution to the food security equation is still a dilemma. This study therefore examined the challenges and vulnerabilities associated with women farmers in accessing and controlling land for sustained agriculture in Northern Ghana. The study was mainly qualitative and utilized various participatory dialogue processes including focus group discussions and key informant interviews of selected women farmer groups, individual farmers, opinion leaders and traditional authorities in eight communities across four districts in three regions of Northern Ghana. The data was analysed thematically. Results of the study showed that women are disadvantaged in all the possible means of acquiring land for agricultural production-- inheritance, marriage, rent, shared cropping, outright purchase, and gift. It was evident that women have appreciable levels of access to land, but have low level of control of such lands for sustained food production. Several factors, such as low income, socio-cultural factors, climate change, mining, urbanization, low level of education, and low levels of awareness of property and inheritance rights, associate women's vulnerability to limited land in the study area. The findings of the study imply that any policy geared toward women empowerment in agriculture must not only target their access to land but also consider enhancing their control over agricultural land. The study therefore recommended that in order to increase food production and security in the study regions, there is the need to strengthen women's capacity to defend their land tenure rights and enhance their access and control over land within the context of natural resource management.展开更多
文摘Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN suspension was prepared by high-pressurehomogenization technique, and then mixed with carbomer gel matrix to get SLN gel. The morphology,particle size with polydispersi-ty index (PI) and zeta potential were examined by atomic forcemicroscopy (AFM) and photon correlation spectroscopy (PCS). The entrapment efficiency, stability andin vitro drug release were also studied. The transdermal drug delivery through porcine ear skin wasevaluated using modified Franz diffusion cells. Results The SLN had a spherical shape with theaverage size of (95.5 - 186.2) nm, the zeta potential of (-26.3- -15.7) mV and the entrapmentefficiency of 67.4%-90.3% for different TAA encapsulated compounds. TAA-SLN carbomer gel had goodstability, the release profile in vitro fitted Higuchi equation. In comparison with conventionalhydrogels, TAA-SLN carbomer gel resulted in higher drug permeation amount and drug deposition withinporcine ear skin after 24 h penetration experiment. Conclusion TAA-SLN carbomer gel is preparedwith stable physicochemical properties. The release profile and improved drug permeation into skinmake it be a promising vehicle for transdermal drug delivery.
文摘AIM: To evaluate how proximal colon polyps interpreted as hyperplastic polyps in 2001 would be interpreted by expert pathologists in 2007.METHODS: ≥ 5 mm in interpreted pathologists 2007 by 3 GI Forty consecutive proximal colon polyps size, removed in 2001, and originally as hyperplastic polyps by general at Indiana University, were reviewed in pathologists.CONCLUSION: Many polyps interpreted as hyperplastic in 2001 were considered sessile serrated lesions by GI pathologists in 2007, but there is substantial inter-observer variation amongst GI pathologists.
基金Under the auspices of National Aeronautics and Space Administration of US(NASA)(No.NNG06GA92G)National Natural Science Foundation of China(No.41171293)
文摘This study examined the spatiotemporal dynamics of colored dissolved organic matter (CDOM) and spectral slope (S), and further to analyze its sources in three productive water supplies (Eagle Creek, Geist and Morse reservoirs) from Indiana, USA. The re- sults showed that he absorption coefficient aCDOM(440) ranged from 0.37 m-1 to 3.93 m-1 with an average of 1.89 ± 0.76 m-1 (±SD) for the aggregated dataset, and S varied from 0.0048 nm -1 to 0.0239 nm-1 with an average of 0.0108 ±0.0040 nmI. A significant relation- ship between S and aCDOM(440) can be fitted with a power equation (S = 0.013 × aCDOM(440)-0.42, R2 = 0.612), excluding data from Geist Reservoir during high flow (12 April 2010) and the Morse Reservoir on 25 June 2010 due to a T-storm achieves even higher determina- tion coefficient (R2 = 0.842). Correlation analysis indicated that aCDOM(440) has strong association with inorganic suspended matter (ISM) concentration (0.231 〈 R2 〈 0.786) for each of the field surveys, and this trend followed the aggregated datasets (R2 = 0.447, p 〈 0.001). In contrast, chlorophyll-a was only correlated with aCDOM(440) in summer and autumn (0.081 〈 R2 〈 0.763), indicating that CDOM is mainly from terrigenous sources in early spring and that phytoplankton contributed during the algal blooming season. The S value was used to characterize CDOM origin. The results indicate that the CDOM source is mainly controlled by hydrological varia- tions, while phytoplankton originated organic matter also closely linked with CDOM dynamics in three productive reservoirs.
基金Supported by the National-Natural Science Foundation of China (No.20576118) and National High Technology Research and Development Program of China (863 Program, No.2006AA02Z210).
文摘The flowability of five kinds of microencapsulation powders,with differentβ-carotene contents and by two alternative particle-forming technologies i.e.spray-drying and starch-catching beadlet technology,was meas- ured.The actual flow properties of the five powders were compared based on bin-flow test,and three flow indexes (Hausner ratio,repose angle and flow index)were measured.It was found that the repose angle is the most suitable index to reflect the flowability of these powders for the particle properties would not be altered due to compaction or tapping during the measuring process.Particle size and particle size distribution play most important roles in the flowability of these granular materials,which was also influenced by other factors like shape,surface texture,sur- face roughness,etc.Microcapsules with wall material of gelatin and a layer of modified starch absorbed on the sur- face showed excellent flowabilities and good mechanical properties,and they are favorable for tabletting to supply β-carotene.
文摘The heat transfer enhancement(HTE) in tubular heat exchangers fitted with vortex-generator(VG) inserts is experimentally investigated. The studied four parameters and ranges are: winglets-pitch ratio(1.33, 2.67, and 4),winglets-length ratio(0.33, 0.67, and 1), winglets-width ratio(0.2, 0.4, and 0.6), and Reynolds number(5200to 12200). The testing fluids are the water and Cu–water nanofluid at the volumetric fraction of 0.2%. The results obtained on HTE, pressure drop, and performance evaluation criterion(PEC) are compared with those for water in a smooth tube. It is found that the VG inserts with lower winglets-pitch ratio and higher winglets-length/width ratios present higher values of HTE and pressure drop. Over the range studied, the maximum PEC of 1.83 is detected with the Cu–water nanofluid inside the tube equipped with a VG insert at the winglets-width ratio of0.6 for the maximum Reynolds number, when the heat transfer rate and pressure drop are 1.24 times and 2.03 times of those in the smooth tube. Generalized regression equations of the Nusselt number, friction factor, and PEC are presented for the tubular heat exchangers with the VG inserts for both water and Cu–water nanofluid.It is concluded that the main advantage of the VG inserts is their simple fabrication and considerable performance, particularly at higher Reynolds number.
基金Supported by the National Natural Science Foundation of China(No.20706041)the Natural Science Foundation of Tianjin(No.09JCYBJC06500)
文摘A Pr-doped TiO2-NTs/SnO2-Sb electrode was prepared by a simple method, cyclic voltarnmetry (CV). The methyl orange (MO)aqueous solution was selected as a simulated wastewater. The ordered microstructural TiO2-NTs substrate was synthesized by an electrochemical method to obtain large specific surface area and high space utilization. The phase structure, electrode surface morphology and electrochemical properties of electrodes were characterized by XRD, SEM and electrochemical technology, respectively. The results showed that praseo- dymium oxide was successfully doped into the SnOz-Sb film by CV method. Due to the doped Pr, the oxygen evo- lution potential increased from 2.25 V to 2.40 V. The degradation of MO was investigated by UV-vis. The Ct/C0(φ) was studied as a function to obtain the optimal parameters, such as the amount of doped Pr, current density and initial dye concentration. In addition, the degradation process followed pseudo-first-order reaction kinetics and the rate constant was 0.099 3 min-1. The result indicated that the introduction of Pr reduced the formation of oxygen vacancies or enhanced the formation of adsorbed hydroxyl radical groups on the surface, thus leading to better activity and stability.
基金Majlesi Branch, Islamic Azad University, for their support
文摘Isoproterenol (ISPR) is an important catecholamine‐based drug that is widely used in the treatment of heart disease. However, overdose of this drug is very dangerous to the human body. In this study, a new sensor based on a pyrogallol red modified‐multiwalled carbon nanotube paste electrode (PGRMMWCNTPE) was prepared and used for high sensitivity determination of ISPR in aqueous solution. Electrocatalytic oxidation of ISPR at the PGRMMWCNTPE was investigated by chronoam‐perometry, cyclic voltammetry, and square‐wave voltammetry. The values of the catalytic rate con‐stant, electron transfer coefficient, and diffusion coefficient for ISPR oxidation were then calculated using voltammetric data. A linear calibration curve was constructed for ISPR concentration in the range 0.8–570μmol/L with a detection limit of 0.47μmol/L ISPR. The sensor was then applied to the determination of ISPR in urine and drug samples with satisfactory results.
基金This research is financially supported by the National Natural Science Foundation (No. 90606027 60501010).
文摘Transcription factor and sequence specific DNA interactions play important roles in drug genome and transcription diagnosis. Gold nanoparticles show high sensitivity, stability and compatibility for biological molecules as electrochemical intercalators. Here unimolecular hairpin oligonucleotides were self-assembled onto Au electrode surface and elongation on solid phase was carried out to double strand oligonucleotides with transcription factor NF-r,13 binding site. Gold nanoparticle-catalyzed Ag deposition was detected by anodic stripping voltammetry (ASV) for NF-kB binding. It was indicated that this method for sequence specific DNA binding protein detection shows pronounced specificity, sensitivity and we can find application in transcription regulation research, open reading frame characterization and functional gene inspection by this method.
文摘Women contribution to all the four pillars of food security (food availability, accessibility, utilization, and sovereignty) has been well established in Ghana and many sub-Saharan African countries. However, the issue of sustainability of their contribution to the food security equation is still a dilemma. This study therefore examined the challenges and vulnerabilities associated with women farmers in accessing and controlling land for sustained agriculture in Northern Ghana. The study was mainly qualitative and utilized various participatory dialogue processes including focus group discussions and key informant interviews of selected women farmer groups, individual farmers, opinion leaders and traditional authorities in eight communities across four districts in three regions of Northern Ghana. The data was analysed thematically. Results of the study showed that women are disadvantaged in all the possible means of acquiring land for agricultural production-- inheritance, marriage, rent, shared cropping, outright purchase, and gift. It was evident that women have appreciable levels of access to land, but have low level of control of such lands for sustained food production. Several factors, such as low income, socio-cultural factors, climate change, mining, urbanization, low level of education, and low levels of awareness of property and inheritance rights, associate women's vulnerability to limited land in the study area. The findings of the study imply that any policy geared toward women empowerment in agriculture must not only target their access to land but also consider enhancing their control over agricultural land. The study therefore recommended that in order to increase food production and security in the study regions, there is the need to strengthen women's capacity to defend their land tenure rights and enhance their access and control over land within the context of natural resource management.