Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design

研究目的：优化获得血红密孔菌（P.sanguineus）的最佳培养基组成,提高耐热漆酶的产量。创新要点：获得了目前文献报道的最高水平的漆酶活力。研究方法：通过单因素试验研究了不同培养基（番茄汁、麦麸、麦芽提取物和葡萄糖细菌蛋白胨培养基）和不同组合诱导剂（大豆油、阿魏酸、没食子酸、二甲基苯胺、酸性蓝62和活性蓝19分别与硫酸铜组合诱导剂）对P.sanguineus产耐热漆酶的影响。在此基础上采用中心组合试验设计,进一步研究了番茄汁培养基结合硫酸铜和大豆油组合诱导剂对P.sanguineus产耐热漆酶的影响。利用SAS10.0和响应面分析方法对试验结果进行了统计分析和建立回归模型。重要结论：通过中心组合设计优化得出P.sanguineus产耐热漆酶的最优培养基条件：以36.8%番茄汁为培养基,以3 mmol/L硫酸铜和1%大豆油作为组合诱导剂。该条件下在10 L搅拌槽生物反应器中漆酶活力达到了143 000 IU/L（2,2＇-联氮双（3-乙基苯并噻唑啉-6-磺酸）为底物,pH值为3.0）。     

An analysis of Ph.D. examiners’ reports in engineering

In recent years, there have been increasing calls for an overall transformation of the nature of engineering Ph.D. programs and the way theses are assessed. There exists a need to understand the examination process to ensure the best quality outcome for candidates in engineering. The work we present in this paper uses data collected between 2003 and 2010 for a total of 1220 Australian Ph.D. theses by analysing examiner reports. Our analysis indicates that Ph.D. theses in engineering, N?=?106, differ considerably from those in other fields in areas such as gender of candidates and examiners and the examiners’ geographical location. We also found that assessment areas such as significance and contribution of the thesis, publications arising from the thesis, breadth, depth and recency of the literature review and communication and editorial correctness are areas in which the proportion of text of engineering examiners' comments differs significantly from other fields.     

University Students' Writing: Types of Errors and Some Comparisons Across Disciplines

The purpose of this study was to identify the writing errors made by 310 first year university students in 13 disciplines using a checklist of five writing error categories, each with a number of sub‐categories. The overall median error rate was 3S.0 errors per 1000 words. Punctuation and capitalisation was by far the most common category of error, and sentence structure, word usage, spelling and vocabulary followed in descending order of frequency. Law and Economics students exhibited the highest error rates while Geography, Mechanical Engineering, Philosophy, English, Statistics, Linguistics, Geology, History and Sociology students had error rates near the median value, and French and Psychology students made fewest errors. The major error sub‐categories that best indicated difference between good and poor writers were the use of commas and some aspects of sentence construction.     

Changes in the level of biogenic amines in cerebrospinal fluid of suicidal attempt cases

The levels of norepinephrine (NE), dopamine (DA) serotonin (5-HT) and its metabolite 5-hydroxyindole acetic acid (5-HIAA) have been determined in the cerebrospinal fluid (CSF) of normal (n=25) and suicidal attempt cases (n=30). A significant decrease in the level of NE (p<0.01), 5-HT(p<0.001) and 5-HIAA (p<0.001) in the CSF of suicide attempt cases were observed as compared to normal controls. It is concluded that CSF 5-HIAA level which is drastically depleted may be used as an early biochemical indicator of suicidal attempt so that it may be treated by the drugs which can enhance the suppressed neurotransmitter activity.     

Isolation ofMycobacterium Tuberculosis 31 kDa antigen protein of diagnostic interest from culture filtrate using anti-ES-31 antibody by affinity chromatography

Proteins secreted into the culture medium byMycobacterium tuberculosis (M. tb) are shown to be source of antigens of immunodiagnostic interest. Anin vitro released 31 kDa antigen ESAS-7F isolated fromM.tb H₃₇Ra culture filtrate by salt precipitation, SDS-PAGE and cation exchange fast protein liquid chromatography (FPLC) was shown earlier to be a diagnostically important antigen fraction. In this report, we describe the isolation of ESAS-7F antigen using monospecific antibody coupled to sepharose CL-4B column. The percentage recovery of ESAS-7F antigen using affinity chromatography was approximately 8% of the total ES antigen proteins compared to 0.05% obtained by conventional purification steps using salt precipitation, SDS-PAGE and FPLC. Similar seroreactivity was observed by the antigen isolated by both the methods in indirect ELISA. Affinity chromatography helped in an increased recovery of ESAS-7F antigen and obviates the need for time consuming conventional purification steps.     

Algorithm-improved high-speed and non-invasive confocal Raman imaging of 2D materials

Confocal Raman microscopy is important for characterizing 2D materials, but its low throughput significantly hinders its applications. For metastable materials such as graphene oxide (GO), the low throughput is aggravated by the requirement of extremely low laser dose to avoid sample damage. Here we introduce algorithm-improved confocal Raman microscopy (ai-CRM), which increases the Raman scanning rate by one to two orders of magnitude with respect to state-of-the-art works for a variety of 2D materials. Meanwhile, GO can be imaged at a laser dose that is two to three orders of magnitude lower than previously reported, such that laser-induced variations of the material properties can be avoided. ai-CRM also enables fast and spatially resolved quantitative analysis, and is readily extended to 3D mapping of composite materials. Since ai-CRM is based on general mathematical principles, it is cost-effective, facile to implement and universally applicable to other hyperspectral imaging methods.     

“Air Anatomy” – Teaching Complex Spatial Anatomy Using Simple Hand Gestures

Spatial understanding of complex anatomical concepts is often a challenge for learners, as well as for educators. It is even more challenging for students with low mental spatial abilities. There are many options to teach spatial relationships, ranging from simple models to high-end three-dimensional (3D) virtual reality tools. Using a randomized controlled trial design, this study explored the use of a unique combination of deictic and iconic hand gestures to enhance spatial anatomical understanding, coining the term “Air Anatomy”. The control group (n = 45) was given a lecture on the anatomy of extraocular muscles, while the intervention group (n = 49) received the same lecture including “Air Anatomy” hand gestures. When compared to the control group, the post-test scores for the intervention group were significantly higher for basic recall (P < 0.001; Mann–Whitney U test) and for the application of knowledge (P = 0.015; Mann–Whitney U test). Students with low to moderate spatial ability (as assessed by a mental rotation test) were found to benefit most by this technique. Students in the intervention group also reported a lower extrinsic cognitive load and higher germane load, when compared to the control group. An instructional skills questionnaire survey indicated the effectiveness of this technique in improving overall classroom experience. Feedback of the students in the intervention group was also favorable for instruction using “Air Anatomy”. The study suggests that “Air Anatomy” is a useful, “no-cost”, accessible method that aids spatial understanding of anatomical concepts.     

A regression analysis of elementary students’ ICT usage vis-à-vis access to technology in Singapore

This paper explores the relationship among ICT infrastructure (i.e., computing devices and Internet), one-to-one computing program and student ICT activities in school. It also looks into the differences of how ICT is being used in the teaching of English, mathematics and science at the elementary school level in relation to the availability of computing devices, Internet connection and one-to-one program. A total of 360 Grade 5 students from three schools (120 students from each school) in the western part of Singapore participated in a questionnaire adapted from the Program for International Student Assessment (PISA) ICT Familiarity Component for Student Questionnaire regarding students’ ICT use. One of the participating schools has implemented a school-based one-to-one computing program for all its students for the past nine years, with the school providing the necessary computing devices for all its Grade 1 to 3 students and a student computer ownership program to encourage all its Grade 4 students to procure their own computing devices to be used till completion of elementary education at Grade 6. The regression analyses suggest that how ICT is being used plays a more significant role in predicting the frequency of ICT use for the various subject areas than ICT infrastructure and one-to-one computing program. Further analysis also reveals that one-to-one computing program and availability of computing devices have a significant interaction effect on the frequency of ICT usage for English but not for mathematics and science—the presence of computing devices seem to have an impact for the usage of ICT for English but not the other two subject areas. The findings concur with earlier studies that there are differences in frequency and how ICT is being used in the teaching of English, mathematics and science.