高师生物教育专业实验教学现状及改革研究——来自阜阳师范学院生科院毕业生的调查报告

通过对阜阳师范学院生科院生物教育专业毕业生的问卷调查,发现了高师生物教育专业实验教学中存在的问题,并从实验室硬件建设、实验课程体系、实验教学目的、实验教学方式、实验管理体制以及实验教学评价等方面提出了改进思路。     

Evaluation of a Hill based muscle model for the energy cost and efficiency of muscular contraction

The purpose of this study was to evaluate a Hill-based mathematical model of muscle energetics and to disclose inconsistencies in existing experimental data. For this purpose, we simulated iso-velocity contractions of mouse fast twitch EDL and slow twitch SOL fibers, and we compared the outcome to experimental results. The experimental results were extracted from two studies published in the literature, which were based on the same methodology but yielded different outcomes (B96 and B93). In the model, energy cost was modeled as the sum of heat and work. Parameters used to model heat rate were entirely independent of the experimental data-sets. Parameters describing the mechanical behavior were derived from both experimental studies. The model was found to accurately predict the muscle energetics and mechanical efficiency of data-set B96. The model could not, however, replicate the energetics and efficiency of SOL and EDL that were found in data-set B93. The model overestimated the shortening heat rate of EDL but, surprisingly, also the mechanical work rate for both muscles. This was surprising since mechanical characteristics of the model were derived directly from the experimental data. It was demonstrated that the inconsistencies in data-set B93 must have been due to some unexplained confounding artifact. It was concluded that the presented model of muscle energetics is valid for iso-velocity contractions of mammalian muscle since it accurately predicts experimental results of an independent data-set (B96). In addition, the model appeared to be helpful in revealing inconsistencies in a second data-set (B93).     

Teaching about Scientific Origins: Taking Account of Creationism

The purpose of this study was to develop a model for measuring experimental design ability based on functional magnetic resonance imaging (fMRI) during biological inquiry. More specifically, the researchers developed an experimental design task that measures experimental design ability. Using the developed experimental design task, they measured both the paper experimental design ability and the fMRI experimental design ability of subjects. Subjects’ paper experimental design ability was measured using the quotient equation of experimental design ability, and their fMRI experimental design ability using the brain connectivity coefficient. According to the fMRI results, differences in design ability existed among subjects in terms of brain connectivity coefficient level during the experimental design task. The experimental design ability brain connectivity coefficient level and quotient for each subject were analysed. Statistically significant correlations between subjects’ connectivity strength level among brain activation regions and quotient value guided the establishment of a measuring model. The model measured experimental design ability and could predict an individual’s experimental design ability quotient using his or her brain connectivity coefficient. Hence, the model developed for this study for measuring experimental design ability based on fMRI may serve as a practical measurement of students’ scientific experimental design ability. Furthermore, this study could serve as a founding theory for measuring models of other scientific processing abilities such as observation, question generation, classification, hypothesis generation and hypothesis evaluation.     

人参皂苷Rg1对抑郁症大鼠抑郁行为和海马神经元损伤、PKA、PKC的影响

摘要 目的：探讨与分析人参皂苷Rg1对抑郁症大鼠抑郁行为和海马神经元损伤、蛋白激酶A（PKA）与蛋白激酶C（PKC）的影响。方法：抑郁症大鼠48只随机平分为三组-模型组、实验1组、实验2组,每组16只大鼠。实验1组、实验2组每天2次灌胃给药（1 mg/mL、4 mg/mL人参皂苷Rg1）,给药体积为10 mL;模型组以相同方式按体重给予双蒸水。观察与记录鼠抑郁行为和海马神经元损伤、PKA、PKC表达变化情况。结果：实验1组、实验2组治疗第7 d、第14 d的逃避潜伏期都显著低于模型组,实验2组与实验1组相比也显著缩短（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的糖水偏好率高于模型组,实验2组与实验1组相比也显著升高（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的血清5-羟色胺较模型组高,血清皮质酮含量较模型组低,实验2组与实验1组对比也有明显差异（P<0.05）。实验1组、实验2组治疗第7 d、第14 d的海马神经元组织的PKA、PKC蛋白相对表达水平显著低于模型组,实验2组与实验1组相比也显著缩短（P<0.05）。结论：人参皂苷Rg1在抑郁症大鼠的应用能改善抑郁行为,增加糖水偏好率,降低逃避潜伏期,还可提高大鼠的血清5-羟色胺含量,降低血清皮质酮含量,降低海马神经元组织的PKA、PKC蛋白表达水平。     

A simple kinetic model for dynein oscillatory activity

A kinetic model for dynein, a molecular motor, complexed with microtubule fragments, is considered. The model explains the experimental observations of oscillatory movements in surprisingly simple axonemal fragments perfused by the ATP solution. The model explains at first time the oscillatory dynein activity as a phenomenon induced by two dynein heads cooperative interaction in the axoneme. The oscillation form, frequency, and amplitude, observed for the model, are close to these experimental characteristics. Kinetic parameters, used in the model, are close to the known experimental parameters.     

Modelling osteoblast adhesion on surface-engineered biomaterials: optimisation of nanophase grain size

A double-layered model is proposed for numerically simulating osteoblast adhesion on surface-engineered biomaterials. The proposed model consists of molecular and cellular motions based on theoretical and experimental evidence and creates predictive simulations from sparse experimental data. The comparison of numerical solutions and experimental data reveals that the proposed model can explain the nonlinear behaviour of osteoblast adhesion on material surfaces in respect to nanophase grain size (0–100 nm). The model further provides insight into the optimisation of nanophase grain size on the surface of the biomaterial.     

Equivalent models of indanol isomers adsorption on cellulose tribenzoate

The adsorption isotherm data of (R)- and (S)-1-indanol and of their racemic mixture on cellulose tribenzoate were measured by frontal analysis. The experimental data for each enantiomers were fitted to the single-component bilangmuir isotherm model. The competitive experimental data were fitted to the ideal adsorption solution model (IAS), the real adsorption solution model (RAS), and the bilangmuir thermodynamically consistent model (BTC). The mass transfer kinetic parameters were estimated from systematic comparisons between the experimental single-component band profiles and profiles calculated using the general rate model (GR) of chromatography coupled with the generalized Maxwell-Stefan equation (GMS). The validation of the isotherm model and of the mass transfer kinetic model was made by comparing the experimental band profiles obtained for solutions of the two enantiomers and those calculated with the competitive GR-GMS model. The excellent agreement observed proves that a combination of the BTC isotherm model and the GMS kinetic model, using the best values of the BTC and GMS parameters estimated from single component experiments, allows an excellent prediction of the binary isotherm and the binary mass transfer kinetics.     

马铃薯生育期进程的动态模拟研究

本研究系统解析和改进了前人关于作物生长温度效应的非线性模型,并对修改后的模型进行了解释,结合4年的田间试验数据和本研究提出的基于高斯方程的作物生长温度效应模型,建立了不同生态条件下马铃薯生育期进程的模拟模型．模型解析了地膜覆盖条件下土壤温度增加对马铃薯生育期进程的数值贡献,模拟了不同生态条件下马铃薯的生育期进展,结果表明模拟值与实测值具有良好的一致性。     

Metabolic dynamics in the human red cell. Part IV--Data prediction and some model computations

The biochemical information on the basic cellular determinants of the human red cell has been compiled into a comprehensive model of the red cell metabolic machinery. This model gives a consistent interpretation--both qualitative and quantitative--of the experimental findings. The predicted steady states and the dynamic states of the model are compared with the experimental findings, and the utility of this model is demonstrated.     

A mathematical model of the proliferative kinetics of cells labelled with brominated DNA precursors

A mathematical model of cell division is presented. It permits analyzing cell proliferation obtained by using BrdU. Numerical experiments show that this model adequately describes experimental data. Application of this model permits decreasing experimental data bulk.     

分子实验技能课程教学模式初探

目的:探索适合临床研究生的分子实验技能课教学模式,提高研究生科研思维能力和实验技能。方法:根据临床研究生的特点,以学生为主体,注重学生科研思维的培养,运用多样化的教学手段,对研究生临床分子实验技能课程的教学方法进行探索。结果:通过实验技能课的学习与培训,临床研究生科研思维能力得到很大的提升,对医学实验研究兴趣增加,取得了很好的教学效果。结论:多元化教学模式比较适合临床研究生实验技能课的教学。     

Construction of rat spinal cord injury model based on Allen’s animal model

The aim of this study is to explore the construction of rat spinal cord injury model guided by Allen's model. Methods: Male rats aged 4–5 weeks and weighing about 250 g are selected as subjects in the Animal Laboratory Center of XX Hospital. Rats are divided into two groups, which are experimental group 1 and experimental group 2, respectively, so as to construct spinal cord injury model in rats. The first group is given 300 g.cm hitting force of T10 spinal cord, and the second group is given 500 g.cm hitting force of T10 spinal cord. Within 25 days after spinal cord injury in Allen's rats, the survival, neurological function, diet, motor ability, tactile ability and auditory ability of the two groups are monitored and evaluated daily. Results: In terms of survival, the survival rate of rats in group 1 is 85%, while that of rats in group 2 is 21%, and there is a concentrated death phenomenon in group 2. In terms of neurological function recovery, experimental group 1 is stable and gets 7 points and experimental group 2 is stable and gets 3 points. In terms of diet, the experimental group 1 is stable and gets 5 points and the experimental group 2 is stable and gets 2 points. In terms of motor ability, the experimental group 1 is stable and gets 5 points and the experimental group 2 is stable and gets 2 points. In tactile sense, experimental group 1 is stable and gets 17 points and experimental group 2 is stable and gets 12 points. It can be seen that the post-operative recovery ability of the experimental group 1 is better than that of the experimental group 2. Conclusion: Under the guidance of Allen's model, compared with the group 2, the experimental group 1 of the rat spinal cord injury model has better recovery in each index. It can be seen that the smaller impact strength is more beneficial to the recovery of rats after spinal cord injury surgery.     

Conceptual, methodological and computational issues concerning the compartmental modeling of a complex biological system: Postprandial inter-organ metabolism of dietary nitrogen in humans

A multi-compartmental model has been developed to describe dietary nitrogen (N) postprandial distribution and metabolism in humans. This paper details the entire process of model development, including the successive steps of its construction, parameter estimation and validation. The model was built using experimental data on dietary N kinetics in certain accessible pools of the intestine, blood and urine in healthy adults fed a [15N]-labeled protein meal. A 13-compartment, 21-parameter model was selected from candidate models of increasing order as being the minimum structure able to properly fit experimental data for all sampled compartments. Problems of theoretical identifiability and numerical identification of the model both constituted mathematical challenges that were difficult to solve because of the large number of unknown parameters and the few experimental data available. For this reason, new robust and reliable methods were applied, which enabled (i) a check that all model parameters could theoretically uniquely be determined and (ii) an estimation of their numerical values with satisfactory precision from the experimental data. Finally, model validation was completed by first verifying its a posteriori identifiability and then carrying out external validation.     

Investigation of Design Space for Freeze-Drying: Use of Modeling for Primary Drying Segment of a Freeze-Drying Cycle

In this work, we explore the idea of using mathematical models to build design space for the primary drying portion of freeze-drying process. We start by defining design space for freeze-drying, followed by defining critical quality attributes and critical process parameters. Then using mathematical model, we build an insilico design space. Input parameters to the model (heat transfer coefficient and mass transfer resistance) were obtained from separate experimental runs. Two lyophilization runs are conducted to verify the model predictions. This confirmation of the model predictions with experimental results added to the confidence in the insilico design space. This simple step-by-step approach allowed us to minimize the number of experimental runs (preliminary runs to calculate heat transfer coefficient and mass transfer resistance plus two additional experimental runs to verify model predictions) required to define the design space. The established design space can then be used to understand the influence of critical process parameters on the critical quality attributes for all future cycles.     

NEW MODEL SYSTEMS FOR EXPERIMENTAL EVOLUTION

Microbial experimental evolution uses a few well‐characterized model systems to answer fundamental questions about how evolution works. This special section highlights novel model systems for experimental evolution, with a focus on marine model systems that can be used to understand evolutionary responses to global change in the oceans.