Cytokinesis-blocked micronucleus assay was applied as a biological dosimeter to detect abnormalities in human peripheral lymphocytes of thirteen students exposed to formaldehyde (FA) during a 12-week (10 h per week) a...Cytokinesis-blocked micronucleus assay was applied as a biological dosimeter to detect abnormalities in human peripheral lymphocytes of thirteen students exposed to formaldehyde (FA) during a 12-week (10 h per week) anatomy class. Breathing-zone air samples colleeted during dissection procedures showed a mean concentration of 2. 37 ppm (3. 17mg/m3 ). Ten students from the same school but without FA exposure served as controls. Chromosome aberrations (CA) and sister chromatid exchanges (SCE) were detected in both groups. The micronuclei (MN) rate (6. 38 ± 2. 50‰ ) and CA rate (5. 92 ±2. 40‰ ) in the FA-exposed group showed a significant increase (P< 0. 01 ) when compared with those of the controls (3. 15 ±1. 46‰and 3. 40 ± 1. 57 % respectively). A correlation between MN and CA in individuals was observed. SCE in the exmpd group were also increased (P< 0. 05), but not so greatly as MN or CA. The results indicated that FA might damage the chromosomes of human lymphocytes.展开更多
This paper will first focus on a brief evaluation ofthe teacher-centered and the learner-centered method-ologies.Then,it presents the practical ways of teach-ing based on the learner-centered approach in class-rooms t...This paper will first focus on a brief evaluation ofthe teacher-centered and the learner-centered method-ologies.Then,it presents the practical ways of teach-ing based on the learner-centered approach in class-rooms to show how students’initiative is given fullplay.Finally,it presents the guidance from fellowstudents and teachers in group activitis.The purposeof the learner-centered approach is to develop students’communicative展开更多
This paper focuses on providing effective feedback for the students in the writing process.Excessivemarking is defective as it reduces their motivation,whereas minimal marking is recommended as itimproves their inner ...This paper focuses on providing effective feedback for the students in the writing process.Excessivemarking is defective as it reduces their motivation,whereas minimal marking is recommended as itimproves their inner drive for writing.In addition,there are other forms of feedback,such as peerfeedback,comments and face-to-face discussions.The students are required to act on the feedback totheir own advantage.It has been proved that the proposed correcting method is time-saving,chal-lenging and efficient.展开更多
文摘Cytokinesis-blocked micronucleus assay was applied as a biological dosimeter to detect abnormalities in human peripheral lymphocytes of thirteen students exposed to formaldehyde (FA) during a 12-week (10 h per week) anatomy class. Breathing-zone air samples colleeted during dissection procedures showed a mean concentration of 2. 37 ppm (3. 17mg/m3 ). Ten students from the same school but without FA exposure served as controls. Chromosome aberrations (CA) and sister chromatid exchanges (SCE) were detected in both groups. The micronuclei (MN) rate (6. 38 ± 2. 50‰ ) and CA rate (5. 92 ±2. 40‰ ) in the FA-exposed group showed a significant increase (P< 0. 01 ) when compared with those of the controls (3. 15 ±1. 46‰and 3. 40 ± 1. 57 % respectively). A correlation between MN and CA in individuals was observed. SCE in the exmpd group were also increased (P< 0. 05), but not so greatly as MN or CA. The results indicated that FA might damage the chromosomes of human lymphocytes.
文摘This paper will first focus on a brief evaluation ofthe teacher-centered and the learner-centered method-ologies.Then,it presents the practical ways of teach-ing based on the learner-centered approach in class-rooms to show how students’initiative is given fullplay.Finally,it presents the guidance from fellowstudents and teachers in group activitis.The purposeof the learner-centered approach is to develop students’communicative
文摘This paper focuses on providing effective feedback for the students in the writing process.Excessivemarking is defective as it reduces their motivation,whereas minimal marking is recommended as itimproves their inner drive for writing.In addition,there are other forms of feedback,such as peerfeedback,comments and face-to-face discussions.The students are required to act on the feedback totheir own advantage.It has been proved that the proposed correcting method is time-saving,chal-lenging and efficient.
