新型生物——人工复合血管研制的初步报告

本文设计一种由胶原和高分子聚合物组成的新型生物一人工复合血管。其研制过程是将包绕有聚酯网的硅胶棒埋入羊的皮下组织,再将形成的经聚酯网为支架的胶原管经醛化处理。作者通过肉眼和SEM观察提出了研制生物——人工复合血管的要点:聚酯网网孔要合适,其与硅胶棒的间隙要恰当,理化处理方法更要选择好。     

Anaerobic Degradation of Propionate by a Mesophilic Acetogenic Bacterium in Coculture and Triculture with Different Methanogens

A mesophilic acetogenic bacterium (MPOB) oxidized propionate to acetate and CO₂ in cocultures with the formate- and hydrogen-utilizing methanogens Methanospirillum hungatei and Methanobacterium formicicum. Propionate oxidation did not occur in cocultures with two Methanobrevibacter strains, which grew only with hydrogen. Tricultures consisting of MPOB, one of the Methanobrevibacter strains, and organisms which are able to convert formate into H₂ plus CO₂ (Desulfovibrio strain G11 or the homoacetogenic bacterium EE121) also degraded propionate. The MPOB, in the absence of methanogens, was able to couple propionate conversion to fumarate reduction. This propionate conversion was inhibited by hydrogen and by formate. Formate and hydrogen blocked the energetically unfavorable succinate oxidation to fumarate involved in propionate catabolism. Low formate and hydrogen concentrations are required for the syntrophic degradation of propionate by MPOB. In triculture with Methanospirillum hungatei and the aceticlastic Methanothrix soehngenii, propionate was degraded faster than in biculture with Methanospirillum hungatei, indicating that low acetate concentrations are favorable for propionate oxidation as well.     

Extinction risk of Chinese angiosperms varies between woody and herbaceous species

Aim

Understanding how species' traits and environmental contexts relate to extinction risk is a critical priority for ecology and conservation biology. This study aims to identify and explore factors related to extinction risk between herbaceous and woody angiosperms to facilitate more effective conservation and management strategies and understand the interactions between environmental threats and species' traits.

Location

China.

Taxon

Angiosperms.

Methods

We obtained a large dataset including five traits, six extrinsic variables, and 796,118 occurrence records for 14,888 Chinese angiosperms. We assessed the phylogenetic signal and used phylogenetic generalized least squares regressions to explore relationships between extinction risk, plant traits, and extrinsic variables in woody and herbaceous angiosperms. We also used phylogenetic path analysis to evaluate causal relationships among traits, climate variables, and extinction risk of different growth forms.

Results

The phylogenetic signal of extinction risk differed among woody and herbaceous species. Angiosperm extinction risk was mainly affected by growth form, altitude, mean annual temperature, normalized difference vegetation index, and precipitation change from 1901 to 2020. Woody species' extinction risk was strongly affected by height and precipitation, whereas extinction risk for herbaceous species was mainly affected by mean annual temperature rather than plant traits.

Main conclusions

Woody species were more likely to have higher extinction risks than herbaceous species under climate change and extinction threat levels varied with both plant traits and extrinsic variables. The relationships we uncovered may help identify and protect threatened plant species and the ecosystems that rely on them.     

Hectogram-scale synthesis of [Aib8, Arg34]-GLP-1 (7–37) by liquid-phase fragment condensation

Based on small-scale synthesis (0.3 g), a 100-g scale-up synthesis of crude [Aib⁸, Arg³⁴]-glucagon-like peptide-1 (GLP-1) (7–37) was completed. The crude [Aib⁸, Arg³⁴]-GLP-1 (7–37) was purified using a dynamic axial compression column 200 (DAC-200). Approximately 61 g of [Aib⁸, Arg³⁴]-GLP-1 (7–37) with a purity of >99% was obtained through one-step reverse-phase chromatography. The purification yield was approximately 92%. The yield from the total reaction was approximately 60%. In summary, we developed an economical and environmentally friendly route to the synthesis and purification of crude [Aib⁸, Arg³⁴]-GLP-1 (7–37), laying a foundation for subsequent industrial production.     

TTLL11 gene is associated with sustained attention performance and brain networks: A genome-wide association study of a healthy Chinese sample

Genetic studies on attention have mainly focused on children with attention-deficit/hyperactivity disorder (ADHD), so little systematic research has been conducted on genetic correlates of attention performance and their potential brain mechanisms among healthy individuals. The current study included a genome-wide association study (GWAS, N = 1145 healthy young adults) aimed to identify genes associated with sustained attention and an imaging genetics study (an independent sample of 483 healthy young adults) to examine any identified genes' influences on brain function. The GWAS found that TTLL11 showed genome-wide significant associations with sustained attention, with rs13298112 as the most significant SNP and the GG homozygotes showing more impulsive but also more focused responses than the A allele carriers. A retrospective examination of previously published ADHD GWAS results confirmed an un-reported, small but statistically significant effect of TTLL11 on ADHD. The imaging genetics study replicated this association and showed that the TTLL11 gene was associated with resting state activity and connectivity of the somatomoter network, and can be predicted by dorsal attention network connectivity. Specifically, the GG homozygotes showed lower brain activity, weaker brain network connectivity, and non-significant brain-attention association compared to the A allele carriers. Expression database showed that expression of this gene is enriched in the brain and that the G allele is associated with lower expression level than the A allele. These results suggest that TTLL11 may play a major role in healthy individuals' attention performance and may also contribute to the etiology of ADHD.     

Sesquiterpenoids from the Resina Commiphora Promoting the Apoptotic Activity of PC-3 Prostate Cancer Cells

Four new germacrane-type sesquiterpenes commiphoranes M1-M4 ( 1 - 4 ) together with eighteen sesquiterpenes were isolated from the Resina Commiphora. The structures and relative configurations of new substances were determined by using spectroscopic methods. Biological activity investigation revealed that nine compounds including 7 , 9 , 14 , 16 , (+)- 17 , (−)- 17 , 18 , 19 , and 20 could induce the apoptosis of prostate cancer originated PC-3 cells, through classic apoptosis signaling pathway, even using flow cytometry showed that the compound (+)- 17 caused apoptosis of PC-3 cells more than 40 %, suggesting their potential therapeutic application in the development of novel drugs against prostate cancer.     

Enhancing electrical outputs of the fuel cells with Geobacter sulferreducens by overexpressing nanowire proteins

Protein nanowires are critical electroactive components for electron transfer of Geobacter sulfurreducens biofilm. To determine the applicability of the nanowire proteins in improving bioelectricity production, their genes including pilA, omcZ, omcS and omcT were overexpressed in G. sulfurreducens. The voltage outputs of the constructed strains were higher than that of the control strain with the empty vector (0.470–0.578 vs. 0.355 V) in microbial fuel cells (MFCs). As a result, the power density of the constructed strains (i.e. 1.39–1.58 W m⁻²) also increased by 2.62- to 2.97-fold as compared to that of the control strain. Overexpression of nanowire proteins also improved biofilm formation on electrodes with increased protein amount and thickness of biofilms. The normalized power outputs of the constructed strains were 0.18–0.20 W g⁻¹ that increased by 74% to 93% from that of the control strain. Bioelectrochemical analyses further revealed that the biofilms and MFCs with the constructed strains had stronger electroactivity and smaller internal resistance, respectively. Collectively, these results demonstrate for the first time that overexpression of nanowire proteins increases the biomass and electroactivity of anode-attached microbial biofilms. Moreover, this study provides a new way for enhancing the electrical outputs of MFCs.     

榄香烯对急性血瘀模型大鼠血液流变性的影响

本文观察了榄香烯对急性血瘀模型大鼠血液流变性的影响。实验结果表明：榄香烯６．２５－２５ｍｇ／ｋｇ／ｄ,ｉｐ×７ｄ,可使血瘀模型鼠的高低切变率全血粘度和还原粘度、血浆粘度、血沉、红细胞聚集指数、纤维蛋白原及红细胞电泳时间等显著降低（Ｐ＜０．０５、Ｐ＜０．０１）。提示榄香烯有活血化瘀作用     

Regulation of cellulase synthesis in mycelial fungi: Participation of ATP and cyclic AMP

Summary ATP and cAMP in 4 strains of mycelial fungi were determined by luciferin-luciferase system and HPLC respectively. Cellulase synthesis was subject to the dual control of ATP and cAMP. No matter what carbon sourse was used, cellulase synthesis was repressed if intracellular ATP concentration was over 10^-7mg/ml. Exogenous cAMP could increase cellulase synthesis under depression conditions.     

Genetics of Soybean-Heterodera glycines Interactions

The soybean cyst nematode, Heterodera glycines, is one of the most economically important pathogens of soybean. Effective management of the nematode is often dependent on the planting of resistant soybean cultivars. During the past 40 years, more than 60 soybean genotypes and plant introductions (PI) have been reported as resistant to H. glycines. About 130 modern soybean cultivars registered in the United States are resistant to certain races of H. glycines. Several resistance genes have been identified and genetically mapped; however, resistance levels in many soybean cultivars are not durable. Some older cultivars are no longer resistant to certain H. glycines populations in many production areas, especially if a soybean monoculture has been practiced. Past soybean registration reports show that all resistant cultivars developed in public institutions from the mid-1960s to the present have been derived from five PIs. This narrow genetic background is fragile. To further complicate the issue, soybean-H. glycines genetic interactions are complex and poorly understood. Studies to identify soybean resistance genes sometimes have overlapped, and the same genes may have been reported several times and designated by different names. Nevertheless, many potential resistance genes in existing germplasm resources have not yet been characterized. Clearly, it is necessary to identify new resistance genes, develop more precise selection methods, and integrate these resistance genes into new cultivars. Rational deployment of resistant cultivars is critical to future sustained soybean production.