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21.
Neda Dadgar Maedeh Koohi Moftakhari Esfahani Sepideh Torabi Seyed Ebrahim Alavi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(4):501-504
This study is aimed to investigate the nanoliposomal artemisinin preparation, and its implementation on breast cancer cells. Side effects have been one of the common challenges of drug usage, as well as cancer treatment. In order to reduce such effects, nanotechnology has been a great help. Nanoliposomes are provided through reverse phase evaporation. In this method, certain proportions of phosphatidylcholine, cholesterol and artemisinin were mixed together. Besides, the obtained formulation was pegylated by using polyethylene glycol 2000 in order to increase its stability and solubility. The mean diameter of non-pegylated and pegylated liposomal artemisinin was determined by Zeta sizer system. The percent of drug released from liposome was performed by dialysis. The encapsulation efficiency of both formulations was estimated by spectrophotometry method. As a result, encapsulation and drug release of nanoliposomal formulation were more than the pegylation of the same formulation. In addition, this study indicated that cytotoxicity effect of pegylated nanoliposomal artemisinin was more, in comparison with nanoliposomal artemisinin. 相似文献
22.
Seyed Ebrahim Alavi Maedeh Koohi Moftakhari Esfahani Fatemeh Alavi Fatemeh Movahedi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2013,28(3):299-302
It is clear that cancer is one of the most mortal diseases in the world and the most prevalent among women is breast cancer. As hydroxyurea (HU)—a drug which is used in chemotherapy—has many adverse effects in long-term despite of its therapeutic properties, we made use of nano drug delivery technology in order to reduce adverse effects and increase therapeutic index. Thus, liposomation is a novel way in drug delivery systems. In this study a mixture of phosphatidylcholine and cholesterol was mixed and HU was added to the resultant mixture. The mean diameter of the nanoliposomal HU measured with the Zeta Sizer device (equal to 402.5 nm) and its encapsulation efficiency was 70.8 %. Besides, using dialysis, the pattern of drug release from nanoliposomes has been studied and the results showed that the drug release of nanoliposomal drug within 28 h was equal to 25.85 %. This study showed that the cytotoxicity effect of nanoliposomal drug is more than that of the standard drug. 相似文献
23.
Delayed-onset muscle soreness refers to the skeletal muscle pain that is experienced following eccentric exercise. The aim of the present study was to examine the physiological effects of physical activity with or without ibuprofen on delayed onset muscle soreness. Forty-four non-athletic male volunteers (age 24.3?±?2.4 years) were randomly assigned to one of four groups: physical activity (n = 11), ibuprofen (n = 11), physical activity and ibuprofen (combination, n = 11), or control (n = 11). The physical activity programme comprised 5?min of walking and jogging, 10?min of static stretching of the hands and shoulder girdle, and 5?min of concentric movements with sub-maximal contractions. The total amount of ibuprofen consumed by a single individual was 2800?mg; this was taken from 1?h before the eccentric actions up to 48?h after it. Delayed onset muscle soreness was induced by performing 70 eccentric contractions of the biceps muscle of the non-dominant side on a modified arm curl machine. Perceived muscle soreness, maximal eccentric contraction, creatine kinase enzyme activity and elbow range of motion were assessed 1?h before and 1, 24 and 48?h after the eccentric actions. The results indicated that, after the eccentric actions, soreness increased (P?<?0.001) across time in all groups, with the highest values being recorded at 24?h. At 24 and 48?h, greater soreness (P <?0.001) was observed in the control group than in the physical activity and combination groups. After the eccentric actions, creatine kinase increased and was elevated (P?<?0.001) compared with baseline in all groups, with values returning to baseline in the physical activity and combination groups by 48?h. However, creatine kinase in the control and ibuprofen groups was still significantly higher than at baseline after 48?h. Creatine kinase was higher (P?<?0.001) in the control group than in physical activity and combination groups at 24 and 48?h. There was also a reduction (P?<?0.001) in elbow range of motion across time. This reduction in elbow range of motion was greater (P?<?0.001) in the control and ibuprofen groups than in the physical activity and combination groups at 1, 24 and 48?h. The reduction in maximum eccentric contraction was greater (P?<?0.001) in the control and ibuprofen groups than in the physical activity group at 24 and 48?h and the combination group at 48?h. In conclusion, the results add to our understanding of the effects of physical activity and the combination of physical activity and ibuprofen in reducing the severity of muscle soreness induced by eccentric exercise. Physical activity conducted before eccentric exercise alleviates muscle soreness. Our results indicate that physical activity with or without ibuprofen helps to prevent delayed-onset muscle soreness. 相似文献
24.
A learning model for enhancing the student's control in educational process using Web 2.0 personal learning environments 
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下载免费PDF全文 Ebrahim Rahimi Jan van den Berg Wim Veen 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(4):780-792
In recent educational literature, it has been observed that improving student's control has the potential of increasing his or her feeling of ownership, personal agency and activeness as means to maximize his or her educational achievement. While the main conceived goal for personal learning environments (PLEs) is to increase student's control by taking advantage of Web 2.0 tools and technologies, there is not a robust learning model available to achieve it. This contribution focuses on proposing a learning model built upon self‐regulated learning and student's control theories and concepts, and supported by the learning affordances of Web 2.0 tools and technologies for enhancing student's control by developing and applying Web 2.0 PLEs. 相似文献
25.
We present a method based on the propagation of highly nonlinear solitary waves (HNSWs) to measure the internal pressure of tennis balls. HNSWs are compact waves that can form and travel in nonlinear systems such as one-dimensional chains of spherical particles, where they are conventionally generated by the mechanical impact of a striker. The speed, amplitude, and duration of these waves can be tuned by modifying the particles’ material or size, or the velocity of the striker. In the present study we numerically investigated the coupling mechanism between the solitary waves propagating along a 1-D granular chain and a tennis ball in contact with the nonlinear medium. A discrete particle model of the beads was coupled to a linear mass–spring–damper model of the tennis ball computed using finite element analysis. Balls with different internal pressures were considered and we found that the time of flight of the HNSWs decreases monotonically with the increase of the internal pressure of the ball. 相似文献
26.
Seyed Ebrahim Alavi Maedeh Koohi Moftakhari Esfahani Soheil Ghassemi Azim Akbarzadeh Gholamhossein Hassanshahi 《Indian journal of clinical biochemistry : IJCB》2014,29(1):84-88
Breast cancer is one of the most frequent cancer types within women population. Hydroxyurea (HU) is a chemotherapy compound for treatment of patients with cancer diagnosis, including breast cancer associated with several adverse effects. In this study, we applied nanotechnology to decreased drug side effects along with improvement of therapeutic index. Liposomation is widely used in modern pharmacological developments in order to enhance the effects of the drugs. To achieve this, in this study a mixture of phosphatidylcholine and cholesterol was made up and HU was added to the resultant mixture, was then pegylated using Polyethylene Glycol 2000 to increase resistance, applicability and solubility. The mean diameters of nanoliposomal and pegylated nanoliposomal HU were measured by Zeta sizer device and obtained about 402.5 and 338.2 nm. The efficiency of non-pegylated and pegylated liposomal HU was 70.8 and 64.2, respectively. Releasing HU in both formulations was estimated about 25.8 and 21.7 %. Also, this study investigated the cytotoxicity effect of nanoliposomal and pegylated nanoliposomal HU using MTT assay. Results of this investigation showed that the cytotoxic properties of pegylated HU was 3.6 % more than those non-pegylated form, while was 38.93 % more than ordinary from of HU. This study showed that the stability, releasing pattern and cytotoxicity of the pegylated nanoliposomal HU is better than that of nanoliposomal HU. 相似文献
27.
This paper identifies the amount of variance in mathematics achievement in high- and low-achieving schools that can be explained by school-level factors, while controlling for student-level factors. The data were obtained from 2679 Iranian eighth graders who participated in the 2007 Trends in International Mathematics and Science Study. Of the total sample, 1422 and 1257 students were from high- and low-achieving schools, respectively. Two-level hierarchical linear modelling was applied. The results indicated that of the total variance in mathematics achievement, 27.95 and 6.70% were due to between-school differences in the high- and low-achieving schools, respectively. Controlling for the school-level factors, the better-performing students were those with a higher level of confidence in learning mathematics in both samples. After controlling for the student-level factors, inadequacies in school resources and school type yielded the strongest link to achievement in the high- and low-achieving schools, respectively. 相似文献
28.
Khosrow Bagheri Noaparast 《Journal of Philosophy of Education》2013,47(4):564-576
The position of the philosophy of education in theoretical or practical philosophy was the main subject of debate between Paul Hirst and Wilfred Carr. In his support for practical philosophy, Carr argues that in order to bridge the theory/practice gap and deconstruct the illusory intactness of philosophy of education from developments in the practical realm, philosophy of education should be assumed as a branch of practical philosophy. Opposed to this argument, Hirst holds that philosophy of education is a second‐order activity and a theoretical matter. Even though both viewpoints seem to be reductive, it is argued here that the controversy of Hirst and Carr on theoretical/practical philosophy of education is more a pseudo‐problem than a real one. This is because Hirst does not dismiss the reflection on action as a source of philosophical knowledge, nor does Carr in fact avoid a second‐order activity in his endeavour in philosophy of education. Nonetheless, it is argued that we should celebrate a moderate dualism in the case of theoretical and practical reason. 相似文献
29.
W L Cornelius K Ebrahim J Watson D W Hill 《Research quarterly for exercise and sport》1992,63(3):311-314
The purpose of the study was to determine the effects of modified Proprioceptive Neuromuscular Facilitation (PNF) flexibility techniques on hip flexion in college males and to determine if local cold application enhances the effectiveness of these techniques. Male subjects (N = 120), with an average age of 21.5 +/- 2.7 years, were randomly assigned to one of four different kinds of stretching treatments with cold or no cold application (15 per group). Range of motion (ROM) in degrees was determined following four stretching techniques: three modified PNF (PCP, 3-PIECP, 3-PIFCP) and a passive stretch (P). Data were analyzed using a 2 (conditions) x 4 (treatments) ANOVA. There were no significant differences in ROM between cold and no cold conditions. Significant differences existed among ROM techniques (p less than .05). Post hoc analyses revealed that the three modified PNF techniques resulted in greater ROM than the passive stretch technique. However, we conclude that cold application does not influence the effectiveness of selected stretching techniques. 相似文献
30.
Ali Ebrahim 《International Journal of Science and Mathematics Education》2012,10(2):293-314
This study compares the effects of two methods of teaching—teacher-centered and cooperative learning—on students’ science
achievement and use of social skills. The sample consists of 163 female elementary science students in 8 intact grade 5 classes
who were assigned to 2 instructional methods and were taught an identical science unit by 4 classroom teachers. The students’
science achievement was measured by a researcher-designed achievement test given to students as a pretest and a posttest.
Students’ social skills were determined by a researcher-designed survey administered as a pretest and posttest. Analysis of
the achievement test scores and the social skills survey responses revealed that cooperative learning strategies have significantly
(p > 0.05) more positive effects on both students’ achievement and social skills than teacher-centered strategies. These results
provide an evidential base to inform policy decisions and encourage and persuade teachers to implement cooperative learning
methods in Kuwaiti classrooms. 相似文献