Advances in the biosynthesis of tetrapyrrole compounds / 生物工程学报

Tetrapyrrole compounds are a class of compounds with important functions. They exist in living organisms and have been widely used in agriculture, food, medicine, and other fields. The cumbersome process and high cost of chemical synthesis, as well as the shortcomings of unstable quality of animal and plant extraction methods, greatly hampered the industrial production and applications of tetrapyrrole compounds. In recent years, the rapid development of synthetic biology has provided new tools for microorganisms to efficiently synthesize tetrapyrrole compounds from renewable biomass resources. This article summarizes various strategies for the biosynthesis of tetrapyrrole compounds, discusses methods to improve its biosynthesis efficiency and future prospects, with the aim to facilitate the research on biosynthesis of tetrapyrrole compounds.

Reliability and validity of nociception coma scale-revised (NCS-R) in patients with disorders of consciousness / 中华行为医学与脑科学杂志

Objective To assess the pain of patients with disorders of consciousness(DOC) and e-valuate the reliability and validity of Chinese version of Nociception Coma Scale- revised ( NCS-R). Meth-ods Sixty-two patients with disorders of consciousness were assessed by NCS-R and the internal reliability, inter-rater reliability,test-retest reliability and concurrent validity was analyzed. Results Cronbach's alpha (α) of internal reliability was 0. 611, test-retest reliability for the NCS-R total scores by spearman was 0. 884. For the subscales,the reliability for the motor,verbal and facial subscale scores by Cronbach's kappa were 0. 856,0. 870 and 0. 856 respectively. Inter-rater reliability for the NCS-R total scores by spearman was 0. 662. For the subscales,the reliability for the motor,verbal and facial subscale scores by Cronbach's kappa were 0. 962,0. 867 and 0. 671 respectively. The spearman coefficient of concurrent validity was 0. 560 (all P<0. 01). Conclusion The NCS-R is a good valid scale and available for Chinese clinician and researchers to assess the pain of DOC patients.

Critical evaluation of particle size distribution models using soil data obtained with a laser diffraction method.

Mathematical descriptions of classical particle size distribution (PSD) data are often used to estimate soil hydraulic properties. Laser diffraction methods (LDM) now provide more detailed PSD measurements, but deriving a function to characterize the entire range of particle sizes is a major challenge. The aim of this study was to compare the performance of eighteen PSD functions for fitting LDM data sets from a wide range of soil textures. These models include five lognormal models, five logistic models, four van Genuchten models, two Fredlund models, a logarithmic model, and an Andersson model. The fits were evaluated using Akaike's information criterion (AIC), adjusted R2, and root-mean-square error (RMSE). The results indicated that the Fredlund models (FRED3 and FRED4) had the best performance for most of the soils studied, followed by one logistic growth function extension model (MLOG3) and three lognormal models (ONLG3, ORLG3, and SHCA3). The performance of most PSD models was better for soils with higher silt content and poorer for soils with higher clay and sand content. The FRED4 model best described the PSD of clay, silty clay, clay loam, silty clay loam, silty loam, loam, and sandy loam, whereas FRED3, MLOG3, ONLG3, ORLG3, and SHCA3 showed better performance for most soils studied.