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1.
Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   
2.
包涵体蛋白 mRNA 是大菜粉蝶颗粒体病毒(pbGV)感染晚期合成的主要信使 RNA.我们从染病晚期幼虫脂肪体中,用饱和苯酚法提取总核酸,用 LiCl 去除其中 DNA,经 Oligo-(dT)纤维素层析柱,mRNA 呈现二个洗脱峰,将洗脱峰组份用尿素-高甲酰胺法制样电镜观察.电镜下 mRNA 分子柔软、粗糙,呈弯曲的线状,分子长度约0.3μ(30个统计)  相似文献   
3.
黄纯农  王君晖 《科技通报》1993,9(4):213-217
ODO冷冻断裂法是一项扫描电镜生物样品制备的有效技术,它在生物医学的形态学研究中发挥了重要作用,把这个技术用到植物离体培养物的超微形态研究,是一个新的尝试.大麦胚性愈伤组织用低浓度的戊二醛前固定,再用ODO冷冻断裂法制备扫描电镜样品.本研究主要观察了淀粉粒和淀粉质体在胚性愈伤组织细胞中的分布,因为淀粉粒沉积的变化和质体结构的变化是去分化和再分化过程中的重要特征之一.本文还图示了自制的冷冻断裂器,并对ODO冷冻断裂法的应用作了一些讨论.  相似文献   
4.
1 Introduction 1 During the last decade a new kind of material called geopolymer has emerged as a viable alternative for many conventional cements and plastics. Geopolymer is inorganic polymer derived from metakaolin and sodium silicate solution. It can be synthesized at low temperature and have useful properties such as high compressive strength. It is stable at temperatures up to 800 °C and even 1150 °C while ordinary Portland cement loses its strength at 500 °C [1]. Several microstruct…  相似文献   
5.
Ferroelectric domain walls differ from domains not only in their crystalline and discrete symmetry, but also in their electronic, magnetic, and mechanical properties. Although domain walls provide a degree of freedom to regulate the physical properties at the nanoscale, the relatively lower controllability prevents their practical applications in nano-devices. In this work, with the advantages of 3D domain configuration detection based on piezoresponse force microscopy, we find that the mobility of three types of domain walls (tail-to-tail, head-to-tail, head-to-head) in (001) BiFeO3 films varies with the applied electrical field. Under low voltages, head-to-tail domain walls are more mobile than other domain walls, while, under high voltages, tail-to-tail domain walls become rather active and possess relatively long average lengths. This is due to the high nucleation energy and relatively low growth energy for charged domain walls. Finally, we demonstrate the manipulation of domain walls through successive electric writings, resulting in well-aligned conduction paths as designed, paving the way for their application in advanced spintronic, memory and communication nano-devices.  相似文献   
6.
Ferrospheres in fly ashes from a coal-fired power plant were extracted by a magnetic separation technique and their microstructure was studied by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and environmental scanning electron microscopy (ESEM). Ferrospheres in fly ashes show significant iron enrichment compared to their respective fly ashes. Iron oxides in ferrospheres mainly occur as minerals magnetite (Fe3O4) and hematite (α-Fe2O3), which are derived mainly from the decomposition and oxidation of iron-bearing minerals in coal during combustion. EDX data indicate that ferrospheres also contain Si, S, Al and Ca resulting from quartz, mullite, anhydrite and amorphous materials. A large percentage of ferrospheres are commonly 5-50 μm in size. The microstructure of ferrospheres includes smooth, polygonal, dendritic, granular and molten drop characteristics. SEM coupled with EDX provided fast and accurate results of the microstructure and chemical composition of ferrospheres, and helped us to assess environmental issues related to the disposal and utilization of fly ashes.  相似文献   
7.
Monitoring of student learning through systematic formative assessment is important for adjusting pedagogical strategies. However, traditional formative assessments, such as quizzes and written assignments, may not be sufficiently timely for making adjustments to a learning process. Technology supported formative assessment tools assess student knowledge, allow for immediate feedback, facilitate classroom dialogues, and have the potential to modify student learning strategies. As an attempt to integrate technology supported formative assessment in the laboratory section of an upper‐level histology course, the interactive application Learning CatalyticsTM, a cloud‐based assessment system, was used. This study conducted during the 2015 Histology courses at Cornell University concluded that this application is helpful for identifying student misconceptions “on‐the‐go,” engaging otherwise marginalized students, and forming a new communication venue between students and instructors. There was no overall difference between grades from topics that used the application and grades from those that did not, and students reported that it only slightly helped improve their understanding of the topic (3.8 ± 0.99 on a five‐point Likert scale). However, they highly recommended using it (4.2 ± 0.71). The major limitation was regarding the image display and graphical resolution of this application. Even though students embrace the use of technology, 39% reported benefits of having the traditional light microscope available. This cohort of students led instructors to conclude that the newest tools are not always better, but rather can complement traditional instruction methods. Anat Sci Educ 10: 328–338. © 2016 American Association of Anatomists.  相似文献   
8.
用布儒斯特角显微镜研究了花生酸分子成膜过程中单分子膜表面形貌的动态变化,发现在气/液界面上花生酸分子首先形成岛状分布,随着表面压的增加形成完整的单分子膜,而当表面压达到崩溃压后薄膜出现裂纹,分子膜重叠,形成多层膜。分析了花生酸单分子膜的形成机理。  相似文献   
9.
Changes in medical school curricula often require educators to develop teaching strategies that decrease contact hours while maintaining effective pedagogical methods. When faced with this challenge, faculty at the University of Cincinnati College of Medicine converted the majority of in‐person histology laboratory sessions to self‐study modules that utilize multiple audiovisual modalities and a virtual microscope platform. Outcomes related to this shift were investigated through performance on in‐house examinations, results of the United States Medical Licensing Examination® (USMLE®) Step 1 Examination, and student feedback. Medical School College Admissions Test® (MCAT®) scores were used as a covariate when comparing in‐house examinations. Results revealed no significant change in performance on in‐house examinations when the content being assessed was controlled (F(2, 506) = 0.676, P = 0.51). A significant improvement in overall practical examination grade averages was associated with the self‐study modules (F(6, 1164) = 10.213, P < 0.01), but gradual changes in examination content may explain this finding. The histology and cell biology portion of USMLE Step 1 Examination remained consistent throughout the time period that was investigated. Student feedback regarding the self‐study modules was positive and suggested that features such as instructor narrated videos were an important component of the self‐study modules because they helped recreate the experience of in‐person laboratory sessions. Positive outcomes from the student perspective and no drop in examination performance suggests that utilizing self‐study modules for histology laboratory content may be an option for educators faced with the challenge of reducing contact hours without eliminating content. Anat Sci Educ 10: 276–285. © 2016 American Association of Anatomists.  相似文献   
10.
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