In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experime...In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experiment and orthogonal experiment.The results showed that the optimum extraction condition was:the ration of ethanol and acetone 1∶1(v/v,containing 0.1%BHT),solid-liquid ratio 1∶30(g/mL),extraction time 7 min,ultrasonic power 240 W,extraction frequency 3 times.Under the above condition,the extraction rate of carotenoids was 85.98%.展开更多
Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga expose...Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.展开更多
By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electri...By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electric field. For a certain infinite set of discrete oscillator frequencies, we obtain the analytical solutions. The ground state polarization of the atom is then calculated. The same result is also obtained through linear response theory.展开更多
Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for...Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil (free of carotenoids) bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses (89%-95%). As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents (expressed in g (100 g)-1 fresh portion) of steam-dried and fried squashes were significantly higher (P 〈 0.05) than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.展开更多
Background Endoplasmic reticulum (ER) stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin (PQS) is able to inhibit excessive ER stress-relat...Background Endoplasmic reticulum (ER) stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin (PQS) is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin (TG), which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG (1 μmol/L) treatment for 24 h, following PQS pre-treatment (160 μg/mL) for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase (Si-PERK) for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 (GRP78), calreticulin, PERK, eukaryotic translation initiation factor 2α (elF2c0, activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.展开更多
For a long time, Vietnam has modifications in all aspects in the society. For many years, Vietnam has improved features in administrative works as well as in different areas, such as public administration, finance, an...For a long time, Vietnam has modifications in all aspects in the society. For many years, Vietnam has improved features in administrative works as well as in different areas, such as public administration, finance, and accounting In the accounting content, budget accounting is an important thing which is worth noting. However, along with the achievements, Vietnam is also facing a number of limitations to be overcome for ensuring transparency in the state budget. Since then, the main purpose of the article is to provide a general picture of budget accounting in Vietnam and what has not been done through finding the relationships with budget regulations and international public sector accounting. The results showed that Vietnam will transform and issue the new law on budget and build up a new model for controlling information published by data accounting system in the future.展开更多
Diesel particulate matter (DPM) is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. Th...Diesel particulate matter (DPM) is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. This paper used computational fluid dynamics method to study the DPM dispersion in a dead-end entry with loading operation. The effects of different push-pull ventilation systems on DPM distribution were evaluated to improve the working conditions for underground miners. The four push-pull systems considered include: long push and short pull tubing; short push and long pull tubing, long push and curved pull tubing, and short push and curved pull tubing. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup local ventilation, select DPM control strategies and for DPM annual training for underground miners.展开更多
The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusi...The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusia (Nees) Bremek, paeonol in Paeonia suffruticosa Andr and piperine in Piper longum L ) The C O group in baicalin, indigo, paeonol and piperine could be reduced to CH OH in acidic solution at the dropping mercury electrode, and showed very good second derivative differential pulse polarographic peak at 1 550V, 1 300V, 1 630V and 0 860V (vs Ag/AgCl) respectively The linear relationship between concentration of baicalin, indigo, paeonol, piperine and peak height was obtained in the concentration range of 4 5×10 5 ~ 2 7×10 4 mol·L 1 , 3 8×10 5 ~ 4 2×10 4 mol·L 1 , 1 0~6 0×10 4 mol·L 1 and 7 0×10 5 ~2 5×10 4 mol·L 1 and the determination limits were 9 0×10 8 mol·L 1 , 8 4×10 9 mol·L 1 , 9 2×10 9 mol·L 1 and 8 7×10 9 mol·L 1 respectively This method is simple, rapid and sensitive, and the results are accurate展开更多
文摘In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experiment and orthogonal experiment.The results showed that the optimum extraction condition was:the ration of ethanol and acetone 1∶1(v/v,containing 0.1%BHT),solid-liquid ratio 1∶30(g/mL),extraction time 7 min,ultrasonic power 240 W,extraction frequency 3 times.Under the above condition,the extraction rate of carotenoids was 85.98%.
文摘Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.
基金Supported by the National Natural Science Foundation of China under Grant No.10805029ZheJiang NSF under Grant No.R6090717the K.C.Wong Magna Foundation of Ningbo University
文摘By using the path integral approach, we investigate the problem of Hooke's atom (two electrons interacting with Coulomb potential in an external harmonic-oscillator potential) in an arbitrary time-dependent electric field. For a certain infinite set of discrete oscillator frequencies, we obtain the analytical solutions. The ground state polarization of the atom is then calculated. The same result is also obtained through linear response theory.
文摘Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil (free of carotenoids) bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses (89%-95%). As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents (expressed in g (100 g)-1 fresh portion) of steam-dried and fried squashes were significantly higher (P 〈 0.05) than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.
基金Acknowledgements This work was supported by International Science and Technology Cooperation Project (2010DFA31690), National Natural Science Foundation of China (81030063 and 81170140) and China Postdoctoral Science Foundation (2014M562608). The authors declare no conflict of interests regarding the publication of this paper.
文摘Background Endoplasmic reticulum (ER) stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin (PQS) is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin (TG), which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG (1 μmol/L) treatment for 24 h, following PQS pre-treatment (160 μg/mL) for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase (Si-PERK) for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 (GRP78), calreticulin, PERK, eukaryotic translation initiation factor 2α (elF2c0, activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.
文摘For a long time, Vietnam has modifications in all aspects in the society. For many years, Vietnam has improved features in administrative works as well as in different areas, such as public administration, finance, and accounting In the accounting content, budget accounting is an important thing which is worth noting. However, along with the achievements, Vietnam is also facing a number of limitations to be overcome for ensuring transparency in the state budget. Since then, the main purpose of the article is to provide a general picture of budget accounting in Vietnam and what has not been done through finding the relationships with budget regulations and international public sector accounting. The results showed that Vietnam will transform and issue the new law on budget and build up a new model for controlling information published by data accounting system in the future.
文摘Diesel particulate matter (DPM) is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners' exposure to DPM has become an increasing concern. This paper used computational fluid dynamics method to study the DPM dispersion in a dead-end entry with loading operation. The effects of different push-pull ventilation systems on DPM distribution were evaluated to improve the working conditions for underground miners. The four push-pull systems considered include: long push and short pull tubing; short push and long pull tubing, long push and curved pull tubing, and short push and curved pull tubing. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup local ventilation, select DPM control strategies and for DPM annual training for underground miners.
文摘The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusia (Nees) Bremek, paeonol in Paeonia suffruticosa Andr and piperine in Piper longum L ) The C O group in baicalin, indigo, paeonol and piperine could be reduced to CH OH in acidic solution at the dropping mercury electrode, and showed very good second derivative differential pulse polarographic peak at 1 550V, 1 300V, 1 630V and 0 860V (vs Ag/AgCl) respectively The linear relationship between concentration of baicalin, indigo, paeonol, piperine and peak height was obtained in the concentration range of 4 5×10 5 ~ 2 7×10 4 mol·L 1 , 3 8×10 5 ~ 4 2×10 4 mol·L 1 , 1 0~6 0×10 4 mol·L 1 and 7 0×10 5 ~2 5×10 4 mol·L 1 and the determination limits were 9 0×10 8 mol·L 1 , 8 4×10 9 mol·L 1 , 9 2×10 9 mol·L 1 and 8 7×10 9 mol·L 1 respectively This method is simple, rapid and sensitive, and the results are accurate