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1.
Emergent patterns of teaching/learning in electronic classrooms 总被引：1，自引：0，他引：1
Ben Shneiderman Ellen Yu Borkowski Maryam Alavi Kent Norman 《Educational technology research and development : ETR & D》1998,46(4):23-42
Novel patterns of teaching/learning have emerged from faculty and students who use our three teaching/learning theaters at
the University of Maryland, College Park. These fully-equipped electronic classrooms have been used by 74 faculty in 264 semester-long
courses since the fall of 1991 with largely enthusiastic reception by both faculty and students. The designers of the teaching/learning
theaters sought to provide a technologically rich environment and a support staff so that faculty could concentrate on changing
the traditional lecture from its unidirectional information flow to a more collaborative activity. As faculty have evolved
their personal styles in using the electronic classrooms, novel patterns of teaching/learning have emerged. In addition to
enhanced lectures, we identified three common patterns: (a) active individual learning, (b) small-group collaborative learning,
and (c) entire-class collaborative learning. 相似文献
2.
Seyed Ebrahim Alavi Hamidreza Mansouri Maedeh Koohi Moftakhari Esfahani Fatemeh Movahedi Azim Akbarzadeh Mohsen Chiani 《Indian journal of clinical biochemistry : IJCB》2014,29(2):150-153
In the present study, paclitaxel was archaeosomed to reduce side effects and improve its therapeutic index. Carriers have made a big evolution in treatment of many diseases in recent years. Lipid carriers are of special importance among carriers. Archaeosome is one of the lipid carriers. Paclitaxel is one of the drugs used to treat breast cancer which has some unwanted side effects despite its therapeutic effects. Archaeosomes were extracted from methanogenic archi bacteria and synthesized with a certain ratio of paclitaxel in PBS. The mean diameter of archaeosomal paclitaxel was measured by Zeta sizer instrument, Drug releasing of archaeosomal paclitaxel was examined within 26 h which results showed that the most drug releasing occurs during first 3 h. The cytotoxicity effect of archaeosomal paclitaxel on breast cancer’s cell line was evaluated by MTT assay which results showed that the cytotoxicity effect of archaeosomal paclitaxel on breast cancer’s cell line is more than that of the standard paclitaxel formulation. The results indicated that new drug delivery of paclitaxel using archaeosome, increases the therapeutic index of the drug. 相似文献
3.
Seyed Kazem Bagherpour Doun Sohrab Halal Khor Dardi Qujeq Hasan Ebrahimi Shahmabadi Seyed Ebrahim Alavi Fatemeh Movahedi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(2):242-245
Cisplatinum (Cispt) is an anti-cancer drug with a low level of solubility. One of Cispt’s solvents is dimethyl sulfoxide (DMSO) which can be substituted with chlorine of drug as Cispt’s solvent. Applying such a solvent in biological studies is impossible due to intense reduction in activity. On the other hand, it is specified that Cispt’s stability is increased in aqueous media by increasing sodium chloride (NaCl) concentration up to 0.9 %. Consequently, we intended to study the effect of DMSO on cytotoxicity of Cispt in presence of sodium. MTT assay was employed to study cytotoxicity effect of Cispt + NaCl + DMSO and Cispt + DMSO on G-292 cell line. Cytotoxicity in dilutions of 300 and 9 (p < 0.01) of Cispt in Cispt + NaCl + DMSO formulation was equal to 78 and 7 %. These values were estimated 79 and 18 % for Cispt + DMSO formulation and 79 and 24 % for free drug. IC50 values demonstrated reduction of 45 % in cytotoxicity of Cispt in Cispt + DMSO formulation. Studying chemical structure of Cispt and Cispt dissolved in DMSO showed that NaCl cannot inhibit inactivating effect of DMSO on Cispt and effect of this solvent on Cispt is independent from presence of NaCl. Results represented that using NaCl does not result in stability and keeping cytotoxicity properties of Cispt in DMSO. Findings suggest more studies for using DMSO as a solvent of Cispt. 相似文献
4.
Abstract A critical success factor for businesses in the twenty‐first century will be their ability to meet the environmental demands for complex coordination of action and rapid adjustments to volatile markets and global competition. Business teams are effective mechanisms for addressing the need for dynamic, flexible organizations that can effectively cope with complexity and turbulence. Business teams are not a new phenomenon, but there is a new element in the equation: the use of information technologies (IT) to leverage team effort. Information technologies can enhance team performance through support of interaction processes by providing two types of functionality: coordination support and task execution support. An agenda for action for moving forward a team‐based organization and use of information technologies for support of business teams is provided. 相似文献
5.
Maedeh Koohi Moftakhari Esfahani Seyed Ebrahim Alavi Fatemeh Movahedi Fatemeh Alavi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2013,28(4):358-360
Regarding that the breast cancer is the most prevalent disease among women, paclitaxel, an anti-cancer drug, could be used in treatment of this disease. As paclitaxel has adverse effects, it was used of nanoliposome drug delivery technology in order to reduce adverse effects and improve drug efficacy. Certain ratios of phosphatidylcholine, cholesterol and paclitaxel were synthesized to prepare nanoliposomal paclitaxel. Using Zeta sizer device, the mean diameter of nanoliposomal paclitaxel was obtained 421.4 nm and its encapsulation efficiency was 91.3 %. By dialysis, drug release in nanoliposome paclitaxel formulation within 28 h was studied which was 5.53 %. This study showed that cytotoxicity effect of nanoliposomal paclitaxel is more than that of the standard form. 相似文献
6.
Hasan Ebrahimi Shahmabadi Seyed Kazem Bagherpour Doun Seyed Ebrahim Alavi Mehri Mortazavi Zahra Saffari Maryam Farahnak Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(3):357-361
Emulsion polymerization was used to synthesize poly butyl cyanoacrylate nanoparticles in presence of steric stabilizer dextran 70. Nanoparticles were characterized by particle size analysis, scanning electron microscopy and light microscopy. Polymerization factors affecting particle size and distribution such as dextran 70, polysorbate 80 (PS 80) and H+ concentration, polymerization time and temperature, and sonication were studied. Distinct concentrations of stabilizer were needed to produce proper nanoparticles. In this case, the appropriate value was 2 % of total volume. At pH 4 significant decrease in production efficiency demonstrated the substantial effect of H+ concentration on nanoparticles. Furthermore significant increases in particle size and distribution was observed at 50 °C compared to room temperature. 0.001 % (v/v) PS 80 represented notable influence on size and distribution. In addition, shaped nanoparticles were obtained by altering polymerization time from 5.5 h to 18 h. Finally, nanoparticle features were influenced by different factors. Appropriate manipulating of such factors can lead to obtaining desirable nanoparticles. 相似文献
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8.
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
9.
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
10.
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