PCR技术在法医生物学中的应用

遗传学认为,DNA是人体性状及遗传变异的物质基础,它是遗传信息的携带者.DNA决定着我们的肤色、性别、身高、健康状况等个体特征.每个人的DNA都是不完全一样的.在法医学上,往往需要鉴别现场留下的物证是否属于犯罪嫌疑人.传统的方法主要是通过指纹、脚印、唇纹、化学物质等物证进行核对,这在一些情况下能起到作用.然而,有时候犯罪分子相当狡猾,或者现场被破坏的很严重,根本找不到上述痕迹.但是在理论上,只要犯罪分子在现场留下血渍、精斑、头发、阴毛、唾液等,通过分析其中的DNA,仍可查获真凶.另外,也可通过分析在现场找到的死者的残留物(如毛发、牙齿、骨骼等)中所含的DNA,来验明他们的真实身份.以前由于这些物证中DNA的含量甚微,再加上无法排除在分析时受到的干扰,DNA分析还或多或少是一种幻想.直到1985年,诺贝尔奖获得者Kary mullis发明了聚合酶链反应(polymerasechain reaction,PCR).再加上1988年Saiki对PCR的重大改进,才使DNA分析在法医学领域的应用取得了惊人的突破.所谓PCR,就是通过特定的DNA序列作为引物,在酶的作用下,经过几十次循环,使目的DNA得以快速复制、扩增,从而得到足以进行检测和分析的目的DNA片段.目的DNA(或称模板DNA)就好象是“轮子”,引物好象有汽车的“方向”,酶好象是“(?)力     

抗氧化剂补充在体育生物科学中运用方向的研究

概述了运动、自由基和抗氧化剂间的联系，总结了目前自由基生物学理论在体育生物科学中的研究运用方向以及各种抗氧化剂的补充情况。     

病原生物学课程整合中实验教学的融合与创新

为加快病原生物学课程整合,在实验教学中对实验教学的内容、教学场地及教学方法的选择、师资队伍建设等方面进行了改革与创新,实践证明实验的有机融合有助于学生临床观念的建立与实践、创新能力的培养。     

Isolation and characterization of a crude oil degrading bacteria from formation water: comparative genomic analysis of environmental Ochrobactrum intermedium isolate versus clinical strains

In this study, we isolated an environmental clone of Ochrobactrum intermedium, strain 2745-2, from the formation water of Changqing oilfield in Shanxi, China, which can degrade crude oil. Strain 2745-2 is aerobic and rod-shaped with optimum growth at 42 °C and pH 5.5. We sequenced the genome and found a single chromosome of 4 800 175 bp, with a G+C content of 57.63%. Sixty RNAs and 4737 protein-coding genes were identified: many of the genes are responsible for the degradation, emulsification, and metabolizing of crude oil. A comparative genomic analysis with related clinical strains (M86, 229E, and LMG3301^T) showed that genes involved in virulence, disease, defense, phages, prophages, transposable elements, plasmids, and antibiotic resistance are also present in strain 2745-2.     

Graphicacy in biology textbooks: analysis of activities with images / Alfabetización gráfica en libros de texto de biología: análisis de las actividades con imágenes

The aim of this study is to analyse how graphicacy is promoted through activities with images of the human body in third to sixth year primary school textbooks from three different publishers. The analysis was based on categories related to type of image, type of task, procedures, cognitive processing level required and whether there are explicit instructions on how to use the image. The results show that illustrations and visual diagrams are the most frequent images. The main task is image interpretation, whereas production tasks are scarce. Moreover, the tasks are not evenly distributed among the different procedures. The processing level required is low and requires superficial processing of the images, resulting in a learning process based on copy and repetition. There is some evidence of activities being sequenced according to educational level. We conclude that the kind of graphicacy found in the textbook activities is insufficient for acquiring competence in the use of images.     

How students reason about matter flows and accumulations in complex biological phenomena: An emerging learning progression for mass balance

In recent years, there has been a strong push to transform STEM education at K-12 and collegiate levels to help students learn to think like scientists. One aspect of this transformation involves redesigning instruction and curricula around fundamental scientific ideas that serve as conceptual scaffolds students can use to build cohesive knowledge structures. In this study, we investigated how students use mass balance reasoning as a conceptual scaffold to gain a deeper understanding of how matter moves through biological systems. Our aim was to lay the groundwork for a mass balance learning progression in physiology. We drew on a general models framework from biology and a covariational reasoning framework from math education to interpret students' mass balance ideas. We used a constant comparative method to identify students' reasoning patterns from 73 interviews conducted with undergraduate biology students. We helped validate the reasoning patterns identified with >8000 written responses collected from students at multiple institutions. From our analyses, we identified two related progress variables that describe key elements of students' performances: the first describes how students identify and use matter flows in biology phenomena; the second characterizes how students use net rate-of-change to predict how matter accumulates in, or disperses from, a compartment. We also present a case study of how we used our emerging mass balance learning progression to inform instructional practices to support students' mass balance reasoning. Our progress variables describe one way students engage in three dimensional learning by showing how student performances associated with the practice of mathematical thinking reveal their understanding of the core concept of matter flows as governed by the crosscutting concept of matter conservation. Though our work is situated in physiology, it extends previous work in climate change education and is applicable to other scientific fields, such as physics, engineering, and geochemistry.     

Isolation,resilience, and faith: Experiences of Black Christian students in biology graduate programs

To increase participation of students of color in science graduate programs, research has focused on illuminating student experiences to inform ways to improve them. In biology, Black students are vastly underrepresented, and while religion has been shown to be a particularly important form of cultural wealth for Black students, Christianity is stigmatized in biology. Very few studies have explored the intersection of race/ethnicity and Christianity for Black students in biology where there is high documented tension between religion and science. Since graduate school is important for socialization and Black students are likely to experience stigmatization of their racial and religious identity, it is important to understand their experiences and how we might be able to improve them. Thus, we interviewed 13 Black Christian students enrolled in biology graduate programs and explored their experiences using the theoretical lens of stigmatized identities. Through thematic content analysis, we revealed that students negotiated experiences of cultural isolation, devaluation of intelligence, and acts of bias like other racially minoritized students in science. However, by examining these experiences at the intersection of race/ethnicity and religion, we shed light on interactions students have had with faculty and peers within the biology community that cultivated perceptions of mistrust, conflict, and stigma. Our study also revealed ways in which students' religious/spiritual capital has positively supported their navigation through biology graduate school. These results contribute to a deeper understanding of why Black Christian graduate students are more likely to leave or not pursue advanced degrees in biology with implications for research and practice that help facilitate their success.     

分子生物学实验教学改革

对分子生物学实验教学的主要问题进行了简单总结,并从优化实验内容、学生撰写实验设计、讨论式实验教学、小班制教学及优化考核方法等8个方面提出了实验教学改革的建议。     

利用网络教学拓展综合素质

生物选修模块开设的主要意义在于可以满足学生多样化发展的需要、提高学生的实践和探究等综合能力,然而由于学校、家长以高分为导向的现状．高中的生物选修课教学并没有真正起到拓展学生素质的作用。网络教学的诸多优势可以使生物选修课教学更好地起到拓展学生素质的作用。     

做一个创新型的生物教师

在实施素质教育,全面深化生物教学改革的创新精神的召唤下．生物教师必须具备创新意识,且要有创新的教育方法．从本质上真正培养学生的创造性。生物教师要做一个创新型的教师,跟上时代的脚步。