Biodegradable reinforced composites are playing a vital role in the variety of application for their outstanding performance. Linear Low Density Polyethylene (LLDPE) and Polyethylene Tere-phthalate (PET) blends were p...Biodegradable reinforced composites are playing a vital role in the variety of application for their outstanding performance. Linear Low Density Polyethylene (LLDPE) and Polyethylene Tere-phthalate (PET) blends were prepared by twin screw extruder in different composition. The mechanical properties in 10% PET with LLDPE blend showed the best results where as tensile strength (TS) 9 MPa and percentage elongation at break (%Eb) 33. Cellulose based reinforced PET + LLDPE composite were prepared by compression molding with the optimized jute content 62% that revealed the highest mechanical properties. Cellulose based composites treated with Acacia catechu (AC) solutions (0.1% - 5% w/v) at different soaking time (2 - 20 min.) where observed significant improvement of the mechanical properties. Cellulose treated with 0.1% AC for 2 minutes soaking time depicted the highest mechanical properties and TS is 115% higher than untreated. Composite prepared with 0.1% AC treated showed the best mechanical properties as tensile strength (TS), bending strength (BS), tensile modulus (TM) and bending modulus (BM) were to be 47 MPa, 39 MPa, 1220 MPa and 1784 MPa respectively. The properties of TS, BS, TM and BM were improved as 9%, 30%, 14% and 34% respectively, which were better to untreated composite. Electrical properties such as dielectric constant and loss of the treated and untreated composites were found to be higher dielectric constant of treated jute composite than that of untreated samples. Water uptake and soil degradation of untreated and treated composites performed in significant study. The effect of AC with cellulose composites has found in remarkable changes in the mechanical properties.展开更多
From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） w...From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） were obtained.Their structures were determined on the basis of spectroscopic analysis.Free-radical scavenging activities of them were evaluated.展开更多
OBJECTIVE:To investigate the effect of black catechu(BC) on the pharmacokinetics of theophylline(CYP1A2 substrate,with narrow therapeutic index)in rabbits.METHODS:In the present investigation the effect of BC on the p...OBJECTIVE:To investigate the effect of black catechu(BC) on the pharmacokinetics of theophylline(CYP1A2 substrate,with narrow therapeutic index)in rabbits.METHODS:In the present investigation the effect of BC on the pharmacokinetics of theophylline,a CYP1A2 substrate was determined.In the study,BC(264 mg/kg,p.o.) or saline(control group) was given to rabbits for 7 consecutive days and on the 8^(th)day theophylline(16 mg/kg) was administered orally one hour after BC or saline treatment.Blood samples were withdrawn at different time intervals(0.5,1,1.5,2,3,4,6,8,12,24 and 36 h) from the marginal ear vein.RESULTS:The pretreatment of rabbits with BC resulted in a significant increase in maximum blood concentration,time of peak concentration and area under the concentration time profile curve until last observation which was about 41.32%,35.71%and 15.03%,respectively.While decreases in clearance,volume of distribution,and half-life were observed.It is suggested that BC pretreatment decreases the CYP1 A metabolic activity leading to increase in bioavailability and decrease in oral clearance of theophylline,which may be due to inhibition of CYP1 A.CONCLUSION:BC can significantly alter theophylline pharmacokinetics in vivo possibly due to inhibition of CYP1 A and P-glycoprotein activity.Based on these results,precaution should be exercised when administering BC with CYP1 A substrate.展开更多
UP446 has been used in both joint supplements and prescription medical food. The purpose of this study was to evaluate the pharmaceutical safety of UP446 via acute and 26-week repeated oral dose toxicity study in SD r...UP446 has been used in both joint supplements and prescription medical food. The purpose of this study was to evaluate the pharmaceutical safety of UP446 via acute and 26-week repeated oral dose toxicity study in SD rats. In acute toxicity study, UP446 was administered by oral gavage to Sprague-Dawley rats (5 males and 5 females) at a dose of 5000 mg/kg. In 26-week repeated oral dose toxicity study, UP446 at doses of 500, 1000 and 2000 mg/kg/day were given orally to groups of rats (10 rats/dose/sex) for 26-week. UP446 at a dose of 5000 mg/kg produced no treatment-related acute toxicity or mortality in any of the animals tested during 14 days of the study. In 26-week repeated dose toxicity study, there was no significant difference in body weight between the control and all treatment groups. Blackish stool and soft stool was observed in one male in the 1000 mg/kg group and in some males and females of 2000 mg/kg group. However, these changes of stool were not considered to be toxic effects because neither histopathological change in gastrointestinal tracks (GIT) nor body weight change were detected. No drug induced abnormalities were found as of body weights, food consumption, ophthalmological examinations, urinalysis, hematology, clinical chemistry, organ weights and gross necropsy in any animals in the dosing groups. These results suggest that the oral lethal dose of UP446 for male and female rats is in excess of 5000 mg/kg and the no observed adverse effect level (NOAEL) of the UP446 for both male and female rats is considered to be greater than 2000 mg/kg/day.展开更多
Biodegradable starch-based chitosan reinforced composite polymeric films were prepared by casting. The chitosan content in the films was varied from 20% to 80% (w/w). Tensile strength (TS) was improved significantly w...Biodegradable starch-based chitosan reinforced composite polymeric films were prepared by casting. The chitosan content in the films was varied from 20% to 80% (w/w). Tensile strength (TS) was improved significantly with the addition of chitosan but elongation at break (EB %) of the composites decreased. Tensile strength of the composites raised more with the addition of the acacia catechu content in the films varied from 0.05% to 0.2% (w/w). The better thermal stability of this prepared film was confirmed by thermo-gravimetric analysis. Structural characterization was done by Fourier transform infrared spectroscopy. Surface morphologies of the composites were examined by scanning electron microscope (SEM) which suggested sufficient homogenization of starch, chitosan and acacia catechu. Water uptake was found lower for final composites in comparison to starch/chitosan and chitosan films. The satisfactory rate of degradation in the soil is expected that the final composite film is within less than 6 months. The developed films intended to use as the alternative of synthetic non-biodegradable colored packaging films.展开更多
文摘Biodegradable reinforced composites are playing a vital role in the variety of application for their outstanding performance. Linear Low Density Polyethylene (LLDPE) and Polyethylene Tere-phthalate (PET) blends were prepared by twin screw extruder in different composition. The mechanical properties in 10% PET with LLDPE blend showed the best results where as tensile strength (TS) 9 MPa and percentage elongation at break (%Eb) 33. Cellulose based reinforced PET + LLDPE composite were prepared by compression molding with the optimized jute content 62% that revealed the highest mechanical properties. Cellulose based composites treated with Acacia catechu (AC) solutions (0.1% - 5% w/v) at different soaking time (2 - 20 min.) where observed significant improvement of the mechanical properties. Cellulose treated with 0.1% AC for 2 minutes soaking time depicted the highest mechanical properties and TS is 115% higher than untreated. Composite prepared with 0.1% AC treated showed the best mechanical properties as tensile strength (TS), bending strength (BS), tensile modulus (TM) and bending modulus (BM) were to be 47 MPa, 39 MPa, 1220 MPa and 1784 MPa respectively. The properties of TS, BS, TM and BM were improved as 9%, 30%, 14% and 34% respectively, which were better to untreated composite. Electrical properties such as dielectric constant and loss of the treated and untreated composites were found to be higher dielectric constant of treated jute composite than that of untreated samples. Water uptake and soil degradation of untreated and treated composites performed in significant study. The effect of AC with cellulose composites has found in remarkable changes in the mechanical properties.
基金supported by the National Science and Technology Project of China(No2009zx09301-003-4-1)and the Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine,Peking Union Medical College,Ministry of Education
文摘From the aqueous extract of Acacia catechu,two new phenolic compounds（3R,4R）-3-（3,4-dihydroxyphenyl）-4-hydroxycy-clohexanone （1） and（4R）-5-（1-（3,4-dihydrophenyl）-3-oxobutyl）-dihydrofuran-2（3H）-one（2） were obtained.Their structures were determined on the basis of spectroscopic analysis.Free-radical scavenging activities of them were evaluated.
基金the Deanship of Scientific Research at King Saud University for funding this research group,No. RG-1435-041
文摘OBJECTIVE:To investigate the effect of black catechu(BC) on the pharmacokinetics of theophylline(CYP1A2 substrate,with narrow therapeutic index)in rabbits.METHODS:In the present investigation the effect of BC on the pharmacokinetics of theophylline,a CYP1A2 substrate was determined.In the study,BC(264 mg/kg,p.o.) or saline(control group) was given to rabbits for 7 consecutive days and on the 8^(th)day theophylline(16 mg/kg) was administered orally one hour after BC or saline treatment.Blood samples were withdrawn at different time intervals(0.5,1,1.5,2,3,4,6,8,12,24 and 36 h) from the marginal ear vein.RESULTS:The pretreatment of rabbits with BC resulted in a significant increase in maximum blood concentration,time of peak concentration and area under the concentration time profile curve until last observation which was about 41.32%,35.71%and 15.03%,respectively.While decreases in clearance,volume of distribution,and half-life were observed.It is suggested that BC pretreatment decreases the CYP1 A metabolic activity leading to increase in bioavailability and decrease in oral clearance of theophylline,which may be due to inhibition of CYP1 A.CONCLUSION:BC can significantly alter theophylline pharmacokinetics in vivo possibly due to inhibition of CYP1 A and P-glycoprotein activity.Based on these results,precaution should be exercised when administering BC with CYP1 A substrate.
文摘UP446 has been used in both joint supplements and prescription medical food. The purpose of this study was to evaluate the pharmaceutical safety of UP446 via acute and 26-week repeated oral dose toxicity study in SD rats. In acute toxicity study, UP446 was administered by oral gavage to Sprague-Dawley rats (5 males and 5 females) at a dose of 5000 mg/kg. In 26-week repeated oral dose toxicity study, UP446 at doses of 500, 1000 and 2000 mg/kg/day were given orally to groups of rats (10 rats/dose/sex) for 26-week. UP446 at a dose of 5000 mg/kg produced no treatment-related acute toxicity or mortality in any of the animals tested during 14 days of the study. In 26-week repeated dose toxicity study, there was no significant difference in body weight between the control and all treatment groups. Blackish stool and soft stool was observed in one male in the 1000 mg/kg group and in some males and females of 2000 mg/kg group. However, these changes of stool were not considered to be toxic effects because neither histopathological change in gastrointestinal tracks (GIT) nor body weight change were detected. No drug induced abnormalities were found as of body weights, food consumption, ophthalmological examinations, urinalysis, hematology, clinical chemistry, organ weights and gross necropsy in any animals in the dosing groups. These results suggest that the oral lethal dose of UP446 for male and female rats is in excess of 5000 mg/kg and the no observed adverse effect level (NOAEL) of the UP446 for both male and female rats is considered to be greater than 2000 mg/kg/day.
文摘Biodegradable starch-based chitosan reinforced composite polymeric films were prepared by casting. The chitosan content in the films was varied from 20% to 80% (w/w). Tensile strength (TS) was improved significantly with the addition of chitosan but elongation at break (EB %) of the composites decreased. Tensile strength of the composites raised more with the addition of the acacia catechu content in the films varied from 0.05% to 0.2% (w/w). The better thermal stability of this prepared film was confirmed by thermo-gravimetric analysis. Structural characterization was done by Fourier transform infrared spectroscopy. Surface morphologies of the composites were examined by scanning electron microscope (SEM) which suggested sufficient homogenization of starch, chitosan and acacia catechu. Water uptake was found lower for final composites in comparison to starch/chitosan and chitosan films. The satisfactory rate of degradation in the soil is expected that the final composite film is within less than 6 months. The developed films intended to use as the alternative of synthetic non-biodegradable colored packaging films.
