Objective: To evaluate the in vitro cytotoxic activity of the fractionated extract as well as isolated compounds of Arum palaestinum Boiss.(A. palaestinum)(black calla lily), and to identify the volatile components wh...Objective: To evaluate the in vitro cytotoxic activity of the fractionated extract as well as isolated compounds of Arum palaestinum Boiss.(A. palaestinum)(black calla lily), and to identify the volatile components which may be responsible for the potential antitumor activity.Methods: A. palaestinum was collected from its natural habitats and subjected to phytochemical analysis for separation of pure compounds. In vitro cytotoxic activity was investigated against four human carcinoma cell lines Hep2, He La, Hep G2 and MCF7 for the fractionated extract and isolated compounds. While, the diethyl ether fraction was subjected to GC–MS analysis as it exhibited the most potent cytotoxic effect to evaluate the active constituents responsible for the cytotoxic activities.Results: Four flavonoid compounds were isolated(luteolin, chrysoeriol, isoorientin,isovitexin) from the diethyl ether and ethyl acetate. The extracts and the pure isolated compounds showed a significant high antiproliferative activity against all investigated cell lines. The GC–MS analysis revealed the separation and identification of 15 compounds representing 95.01% of the extract and belonging to different groups of chemical compounds.Conclusions: The present study is considered to be the first report on the cytotoxic activities carried out on different selected fractions and pure compounds of A. palaestinum to provide evidences for its strong antitumor activities. In addition,chrysoeriol and isovitexin compounds were isolated for the first time from the studied taxa.展开更多
Background： Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group...Background： Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group classes among the mainstream dance and fitness audiences; however, the efficacy of these activities for the purposes of health promotion currently remains unclear. The purpose of this study was to simultaneously assess the physiological responses and psychological experiences during salsa dance and Zumba fitness in a community sample of physically inactive women. Methods： Twenty-four participants, aged 22-56 years, visited the laboratory to perform a graded exercise test for determination of maximal oxygen uptake and maximal heart rate. The participants then attended 2 partnered salsa dance and 2 non-partnered Zumba fitness classes each in a counterbalanced order over a 2-week period. The 1-h classes were taught by certified instructors in established venues in the Royal Borough of Kingston and the surrounding communities of London, UK. Physiological data were collected using a wrist-worn ActiGraph wGT3X＋ acceler- ometer with accompanying heart rate monitor and were processed using previously validated dance-specific techniques. Psychological experiences were measured via the Subjective Exercise Experiences Scale. Results： There was a significantly higher （p 〈 0.001） total time spent in moderate-to-vigorous physical activity （51.2± 3.1 vs. 32.6 ±5.9 min）, total energy expenditure （411±66 vs. 210 ± 46 kcal）, and total step count （6773 ± 556 vs. 4108 ±781 steps） during Zumba fitness when compared to salsa dance. Significant pre- to post-class improvements in positive well-being （p 〈 0.01, partial 7/2 = 0.4l） and psychological distress （p 〈 0.001, partial 02 = 0.72） were simultaneously observed for both salsa dance and Zumba fitness. Conclusion： The acute responses to classes of partnered Latin dance and non-partnered Latin-themed aerobic dance suggest that in physically inactive women participation is indeed efficacious in terms of community-based physical activity and psychosocial health promotion.展开更多
Objective To assess the risk factors for upper extremity-work-related musculoskeletal disorders（UE-WMSD） on 13 prod ucti on lines in an airbag factory using the threshold limit values-American conference of industri...Objective To assess the risk factors for upper extremity-work-related musculoskeletal disorders（UE-WMSD） on 13 prod ucti on lines in an airbag factory using the threshold limit values-American conference of industrial hygienists-hand activity level（TLV-ACGIH-HAL） method and introduce the ergonomic improvement to reduce the repe titi veness and the peak force（Pf）.Methods Professional exposure level on 13 production lines in a automobile factory was measured using the TLV-ACGIH-HAL method and a further risk was assessed according to the ergonomic improvement.Results The first assessment of 9 produc tion lines showed that the professional exposure level was above the TLV or HAL limit.The second assessment showed that the professional exposure level was below the AL limit on all production lines except 1,in which the professional exposure level was between TLV and HAL.Conclusion The assessment of UE-WMSD-related risk can ide ntif y the riskiest emplacements and evaluate the reduc tion of risk in professional exposure through interventi ons of structuralorganizati onal type.展开更多
This article explains why it is important to organize communicative activities in English teaching, as well as some theories and basic principles related to this respect. It is made up of four parts: 1) General Introd...This article explains why it is important to organize communicative activities in English teaching, as well as some theories and basic principles related to this respect. It is made up of four parts: 1) General Introduction; 2) How to organize communicative activities; 3) What educational objectives are to be reached through communicative activities and 4) Conclusion.The article is written to exchange ideas on organizing communicative activities in English classes with other English teachers as me.展开更多
基金Support by Science and Technology Development Fund,with Grant No.4402
文摘Objective: To evaluate the in vitro cytotoxic activity of the fractionated extract as well as isolated compounds of Arum palaestinum Boiss.(A. palaestinum)(black calla lily), and to identify the volatile components which may be responsible for the potential antitumor activity.Methods: A. palaestinum was collected from its natural habitats and subjected to phytochemical analysis for separation of pure compounds. In vitro cytotoxic activity was investigated against four human carcinoma cell lines Hep2, He La, Hep G2 and MCF7 for the fractionated extract and isolated compounds. While, the diethyl ether fraction was subjected to GC–MS analysis as it exhibited the most potent cytotoxic effect to evaluate the active constituents responsible for the cytotoxic activities.Results: Four flavonoid compounds were isolated(luteolin, chrysoeriol, isoorientin,isovitexin) from the diethyl ether and ethyl acetate. The extracts and the pure isolated compounds showed a significant high antiproliferative activity against all investigated cell lines. The GC–MS analysis revealed the separation and identification of 15 compounds representing 95.01% of the extract and belonging to different groups of chemical compounds.Conclusions: The present study is considered to be the first report on the cytotoxic activities carried out on different selected fractions and pure compounds of A. palaestinum to provide evidences for its strong antitumor activities. In addition,chrysoeriol and isovitexin compounds were isolated for the first time from the studied taxa.
文摘Background： Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group classes among the mainstream dance and fitness audiences; however, the efficacy of these activities for the purposes of health promotion currently remains unclear. The purpose of this study was to simultaneously assess the physiological responses and psychological experiences during salsa dance and Zumba fitness in a community sample of physically inactive women. Methods： Twenty-four participants, aged 22-56 years, visited the laboratory to perform a graded exercise test for determination of maximal oxygen uptake and maximal heart rate. The participants then attended 2 partnered salsa dance and 2 non-partnered Zumba fitness classes each in a counterbalanced order over a 2-week period. The 1-h classes were taught by certified instructors in established venues in the Royal Borough of Kingston and the surrounding communities of London, UK. Physiological data were collected using a wrist-worn ActiGraph wGT3X＋ acceler- ometer with accompanying heart rate monitor and were processed using previously validated dance-specific techniques. Psychological experiences were measured via the Subjective Exercise Experiences Scale. Results： There was a significantly higher （p 〈 0.001） total time spent in moderate-to-vigorous physical activity （51.2± 3.1 vs. 32.6 ±5.9 min）, total energy expenditure （411±66 vs. 210 ± 46 kcal）, and total step count （6773 ± 556 vs. 4108 ±781 steps） during Zumba fitness when compared to salsa dance. Significant pre- to post-class improvements in positive well-being （p 〈 0.01, partial 7/2 = 0.4l） and psychological distress （p 〈 0.001, partial 02 = 0.72） were simultaneously observed for both salsa dance and Zumba fitness. Conclusion： The acute responses to classes of partnered Latin dance and non-partnered Latin-themed aerobic dance suggest that in physically inactive women participation is indeed efficacious in terms of community-based physical activity and psychosocial health promotion.
文摘Objective To assess the risk factors for upper extremity-work-related musculoskeletal disorders（UE-WMSD） on 13 prod ucti on lines in an airbag factory using the threshold limit values-American conference of industrial hygienists-hand activity level（TLV-ACGIH-HAL） method and introduce the ergonomic improvement to reduce the repe titi veness and the peak force（Pf）.Methods Professional exposure level on 13 production lines in a automobile factory was measured using the TLV-ACGIH-HAL method and a further risk was assessed according to the ergonomic improvement.Results The first assessment of 9 produc tion lines showed that the professional exposure level was above the TLV or HAL limit.The second assessment showed that the professional exposure level was below the AL limit on all production lines except 1,in which the professional exposure level was between TLV and HAL.Conclusion The assessment of UE-WMSD-related risk can ide ntif y the riskiest emplacements and evaluate the reduc tion of risk in professional exposure through interventi ons of structuralorganizati onal type.
文摘This article explains why it is important to organize communicative activities in English teaching, as well as some theories and basic principles related to this respect. It is made up of four parts: 1) General Introduction; 2) How to organize communicative activities; 3) What educational objectives are to be reached through communicative activities and 4) Conclusion.The article is written to exchange ideas on organizing communicative activities in English classes with other English teachers as me.
