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: Racecadotril is a specific enkephalinase inhibitor that exhibits intestinal antisecretory activity without affecting intestinal transit. Loperamide is an effective anti-diarrheal agent, but it usually induces con...AIM: Racecadotril is a specific enkephalinase inhibitor that exhibits intestinal antisecretory activity without affecting intestinal transit. Loperamide is an effective anti-diarrheal agent, but it usually induces constipation. This study is to compare the efficacy, safety, and tolerability of racecadotril versus loperamide in the outpatient treatment of acute diarrhea in adults. METHODS: A two-center, randomized, parallel-group, single-blind study was carried out to compare the efficacy, tolerability, and safety of racecadotril (100 mg thrics daily) and loperamide (2.0 mg 2 twics daily) in 62 adult patients suffering from acute diarrhea. The main efficacy criterion used was the duration of diarrhea after beginning the treatment (in hours). Other signs and symptoms were also evaluated. RESULTS: The clinical success rates for these anti-diarrheal treatments were 95.7% and 92.0% for racecadotril and loperamide respectively. Patients on racecadotril had a median duration of diarrhea of 19.5 h compared with a median of 13 h for patients on loperamide. Rapid improvement in anal burn and nausea was found for each drug. However, more patients on loperamide suffered from reactive constipation (29.0% vs 12.9%). Itching, another adverse event was notably higher in the racecadotril group (28.6% vs 0%). With regard to other adverse events, the two medications showed similar occurrence rates and similar concomitant medication usage rates. CONCLUSION: Racecadotril and loperamide are rapid, equally effective treatments for acute diarrhea in adults, but loperamide treatment is associated with a higher incidence of treatment-related constipation.展开更多
The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors （more in general determ...The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors （more in general determinants or risk factors）. However, when the follow-up period is very long and Kaplan-Meier survival curves are adopted, or Kaplan- Meier-based more complex models such as Cox＇s analysis are used, clinical （or epidemiological） reality may well be distorted since by these survival methods risks tend to be overestimated, whereas survival tends to be reduced.展开更多
At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological ...At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological effects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals(As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refi ne ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index(PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single effects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefl y, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved signifi cantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.展开更多
This paper discusses the first eigenvalue on a compact Riemann manifold with the negative lower bound Ricci curvature. Let M be a compact Riemann manifold with the Ricci curvature≥-R, R=const. ≥0 and d is the diamet...This paper discusses the first eigenvalue on a compact Riemann manifold with the negative lower bound Ricci curvature. Let M be a compact Riemann manifold with the Ricci curvature≥-R, R=const. ≥0 and d is the diameter of M. Our main result is that the first eigenvalue λ1 of M satisfies λ1≥π^2/d^2-0.518R.展开更多
The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) o...The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) of piles. Based on a two-parameter,hyperbolic curve-fitting equation describing the load-settlement relation of piles, the SLS model factor is defined. Then, taking into account the uncertainties of load-settlement model, load and bearing capacity of piles, the formula for computing the SLS reliability index(βsls) is obtained using the mean value first order second moment(MVFOSM) method. Meanwhile, the limit state function for conducting the SLS reliability analysis by the Monte Carlo simulation(MCS) method is established. These two methods are finally applied to determine the SLS target reliability index. Herein, the limiting tolerable settlement(slt) is treated as a random variable. For illustration, four load test databases from South Africa are compiled again to conduct reliability analysis and present the recommended target reliability indices. The results indicate that the MVFOSM method overestimates βsls compared to that computed by the MCS method. Besides, both factor of safety(FS) and slt are key factors influencing βsls, so the combination of FS and βsls is welcome to be used for the SLS reliability analysis of piles when slt is determined. For smaller slt, pile types and soils conditions have significant influence on the SLS target reliability indices; for larger slt, slt is the major factor having influence on the SLS target reliability indices. This proves that slt is the most key parameter for the determination of the SLS target reliability index.展开更多
In the present study,we optimized the ceftriaxone dosing regimens based on pharmacokinetic/pharmacodynamic(PK/PD)principles using Monte Carlo simulation(MCS).Based on PK/PD theory,MCS was performed using Crystal Ball ...In the present study,we optimized the ceftriaxone dosing regimens based on pharmacokinetic/pharmacodynamic(PK/PD)principles using Monte Carlo simulation(MCS).Based on PK/PD theory,MCS was performed using Crystal Ball software combining PK and PD parameters with 10000 simulation runs to calculate the probability of target attainment(PTA)and cumulative fraction of response(CFR)for the seven clinically common dosing regimens of ceftriaxone(1 g qd,1.5 g qd,1 g bid,2 g qd,1 g tid,1.5 g bid,and 2 g bid).A%fT≥50 as the target value expected to achieve satisfactory clinical efficacy and a dosing regimen with an obtained CFR≥90%or the ability to achieve the highest PTA was used as a reasonable choice for empirical antimicrobial therapy,i.e.the clinically optimal regimen.All eight pathogenic bacteria had a CFR>90%when the dosing regimen was 2 g bid and 1 g tid,seven pathogenic bacteria had a CFR>90%when the dosing regimen was 1 g bid and 1.5 g bid,except for Pseudomonas aeruginosa,and all pathogenic bacteria had a CFR<90%when the dosing regimen was 1 g qd and 1.5 g qd.The dosing regimens of 2 g bid and 1 g tid were effective against all eight pathogenic bacteria infections,and 1 g bid and 1.5 g bid dosing regimens were effective against the other seven pathogenic bacteria except for Pseudomonas aeruginosa.展开更多
An affirmative answer to a conjecture of K. Ogiue formulated in [2] is given, namely, thefollowing result is proved:Let Ma (n ≥ 2) be a complete Kaehler hypersurface immersed in a complex projective spaceCPn+1. Ifeve...An affirmative answer to a conjecture of K. Ogiue formulated in [2] is given, namely, thefollowing result is proved:Let Ma (n ≥ 2) be a complete Kaehler hypersurface immersed in a complex projective spaceCPn+1. Ifevery sectional curvature of Mn is positive, then Mn is totally geodesic in CPn+1.展开更多
We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The avera...We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The average lifetime of the metastable state was observed to increase with the magnitude of the gradient of applied field. In the high gradient regime, the system was observed to show two distinct region of up and down spins. The interface or the domain wall was observed to move as one increases the gradient. The displacement of the mean position of the interface was observed to increase with the gradient as hyperbolic tangent function. The roughness of the interface was observed to decay exponentially as the gradient increases. The number of spin flip per site was observed to show a discontinuity in the vicinity of the domain wall. The amount of the discontinuity was found to diverge with the system size as a power law fashion with an exponent 5/3.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: Racecadotril is a specific enkephalinase inhibitor that exhibits intestinal antisecretory activity without affecting intestinal transit. Loperamide is an effective anti-diarrheal agent, but it usually induces constipation. This study is to compare the efficacy, safety, and tolerability of racecadotril versus loperamide in the outpatient treatment of acute diarrhea in adults. METHODS: A two-center, randomized, parallel-group, single-blind study was carried out to compare the efficacy, tolerability, and safety of racecadotril (100 mg thrics daily) and loperamide (2.0 mg 2 twics daily) in 62 adult patients suffering from acute diarrhea. The main efficacy criterion used was the duration of diarrhea after beginning the treatment (in hours). Other signs and symptoms were also evaluated. RESULTS: The clinical success rates for these anti-diarrheal treatments were 95.7% and 92.0% for racecadotril and loperamide respectively. Patients on racecadotril had a median duration of diarrhea of 19.5 h compared with a median of 13 h for patients on loperamide. Rapid improvement in anal burn and nausea was found for each drug. However, more patients on loperamide suffered from reactive constipation (29.0% vs 12.9%). Itching, another adverse event was notably higher in the racecadotril group (28.6% vs 0%). With regard to other adverse events, the two medications showed similar occurrence rates and similar concomitant medication usage rates. CONCLUSION: Racecadotril and loperamide are rapid, equally effective treatments for acute diarrhea in adults, but loperamide treatment is associated with a higher incidence of treatment-related constipation.
文摘The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors （more in general determinants or risk factors）. However, when the follow-up period is very long and Kaplan-Meier survival curves are adopted, or Kaplan- Meier-based more complex models such as Cox＇s analysis are used, clinical （or epidemiological） reality may well be distorted since by these survival methods risks tend to be overestimated, whereas survival tends to be reduced.
基金Supported by the Science and Technology Project of North China Sea Branch of State Oceanic Administration(No.2014B02)
文摘At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological effects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals(As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refi ne ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index(PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single effects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefl y, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved signifi cantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.
基金Supported by the NNSF of China(10271011)Supported by LIMB of the Ministry of Education China
文摘This paper discusses the first eigenvalue on a compact Riemann manifold with the negative lower bound Ricci curvature. Let M be a compact Riemann manifold with the Ricci curvature≥-R, R=const. ≥0 and d is the diameter of M. Our main result is that the first eigenvalue λ1 of M satisfies λ1≥π^2/d^2-0.518R.
基金Projects(51278216,51308241)supported by the National Natural Science Foundation of ChinaProject(2013BS010)supported by the Funds of Henan University of Technology for High-level Talents,China
文摘The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) of piles. Based on a two-parameter,hyperbolic curve-fitting equation describing the load-settlement relation of piles, the SLS model factor is defined. Then, taking into account the uncertainties of load-settlement model, load and bearing capacity of piles, the formula for computing the SLS reliability index(βsls) is obtained using the mean value first order second moment(MVFOSM) method. Meanwhile, the limit state function for conducting the SLS reliability analysis by the Monte Carlo simulation(MCS) method is established. These two methods are finally applied to determine the SLS target reliability index. Herein, the limiting tolerable settlement(slt) is treated as a random variable. For illustration, four load test databases from South Africa are compiled again to conduct reliability analysis and present the recommended target reliability indices. The results indicate that the MVFOSM method overestimates βsls compared to that computed by the MCS method. Besides, both factor of safety(FS) and slt are key factors influencing βsls, so the combination of FS and βsls is welcome to be used for the SLS reliability analysis of piles when slt is determined. For smaller slt, pile types and soils conditions have significant influence on the SLS target reliability indices; for larger slt, slt is the major factor having influence on the SLS target reliability indices. This proves that slt is the most key parameter for the determination of the SLS target reliability index.
基金2019 Second Hospital of Hebei Medical University Pro ject(Grant No.2h2019042)。
文摘In the present study,we optimized the ceftriaxone dosing regimens based on pharmacokinetic/pharmacodynamic(PK/PD)principles using Monte Carlo simulation(MCS).Based on PK/PD theory,MCS was performed using Crystal Ball software combining PK and PD parameters with 10000 simulation runs to calculate the probability of target attainment(PTA)and cumulative fraction of response(CFR)for the seven clinically common dosing regimens of ceftriaxone(1 g qd,1.5 g qd,1 g bid,2 g qd,1 g tid,1.5 g bid,and 2 g bid).A%fT≥50 as the target value expected to achieve satisfactory clinical efficacy and a dosing regimen with an obtained CFR≥90%or the ability to achieve the highest PTA was used as a reasonable choice for empirical antimicrobial therapy,i.e.the clinically optimal regimen.All eight pathogenic bacteria had a CFR>90%when the dosing regimen was 2 g bid and 1 g tid,seven pathogenic bacteria had a CFR>90%when the dosing regimen was 1 g bid and 1.5 g bid,except for Pseudomonas aeruginosa,and all pathogenic bacteria had a CFR<90%when the dosing regimen was 1 g qd and 1.5 g qd.The dosing regimens of 2 g bid and 1 g tid were effective against all eight pathogenic bacteria infections,and 1 g bid and 1.5 g bid dosing regimens were effective against the other seven pathogenic bacteria except for Pseudomonas aeruginosa.
文摘An affirmative answer to a conjecture of K. Ogiue formulated in [2] is given, namely, thefollowing result is proved:Let Ma (n ≥ 2) be a complete Kaehler hypersurface immersed in a complex projective spaceCPn+1. Ifevery sectional curvature of Mn is positive, then Mn is totally geodesic in CPn+1.
文摘We have studied the reversal of magnetisation in Ising ferromagnet by the field having gradient along a particular direction. We employed the Monte Carlo simulation with Metropolis single spin nip algorithm. The average lifetime of the metastable state was observed to increase with the magnitude of the gradient of applied field. In the high gradient regime, the system was observed to show two distinct region of up and down spins. The interface or the domain wall was observed to move as one increases the gradient. The displacement of the mean position of the interface was observed to increase with the gradient as hyperbolic tangent function. The roughness of the interface was observed to decay exponentially as the gradient increases. The number of spin flip per site was observed to show a discontinuity in the vicinity of the domain wall. The amount of the discontinuity was found to diverge with the system size as a power law fashion with an exponent 5/3.
