Protein S-nitrosylation regulates proteostasis and viability of hematopoietic stem cell during regeneration

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Front Cover: Wide‐field monitoring and real‐time local recording of microvascular networks on small animals with a dual‐raster‐scanned photoacoustic microscope

A dual‐raster‐scanned photoacoustic microscope (DRS‐PAM) was reported, which integrates a two‐dimensional motorized translation stage for large field‐of‐view imaging and a two‐axis fast galvanometer scanner for real‐time imaging. The DRS‐PAM provides a flexible transition from wide‐field monitoring the vasculature of organs to real‐time imaging of local dynamics. Further details can be found in the article by Fei Yang, Zhiyang Wang, Wuyu Zhang, et al. ( e202000022 ).

     

Beta blockers in heart failure haemodynamics,clinical effects and modes of action

Treatment for heart failure may be directed at relieving symptoms and/or improving prognosis. One of the primary aims of research in heart failure is to alter the progressive decline in pump function and thereby improve prognosis.For many years, diuretics have been known as therapeutics in heart failure and they are very effective in symptom relief. Vasodilators and inotropes also have beneficial effects on symptom relief especially in the acute phase through changes in cardiac output, filling pressures and renal perfusion. However, although these treatments produce short-term relief, none have been shown to influence the disease process and thereby improve mortality. Indeed, many of these drugs may even lead to untoward long-term clinical outcomes as has been shown for example for milrinone and ibopamine.There is overwhelming evidence that drugs interfering with the neurohormonal activation in heart failure not only produce symptomatic relief but are also capable of attenuating disease progression with concomitant reductions in both morbidity and mortality. About a decade ago, convincing and large-scale evidence showed that ACE inhibitors produced favourable effects by antagonising the activated renin-angiotensin system. More recently, β-blockers, which antagonise the activated sympathetic system, were shown to be beneficial in the long term in moderate severe heart failure in terms of significant improvements in both morbidity and mortality. The RALES study further amplified the concept that drugs that interact in the neurohormonal system have beneficial effects. In this study, spironolactone, a weak, potassium-sparing diuretic counteracting aldosterone showed a reduction in mortality in more severe forms of heart failure.     

High-security photoacoustic identity recognition by capturing hierarchical vascular structure of finger

Currently, most biometric methods mainly use single features, making them easily forged and cracked. In this study, a novel triple-layers biometric recognition method, based on photoacoustic microscopy, is proposed to improve the security of biometric identity recognition. Using the photoacoustic (PA) dermoscope, three-dimensional absorption-structure information of the fingers was obtained. Then, by combining U-Net, Gabor filtering, wavelet analysis and morphological transform, a lightweight algorithm called photoacoustic depth feature recognition algorithm (PADFR) was developed to automatically realize stratification (the fingerprint, blood vessel fingerprint and venous vascular), extracting feature points and identity recognition. The experimental results show that PADFR can automatically recognize the PA hierarchical features with an average accuracy equal to 92.99%. The proposed method is expected to be widely used in biometric identification system due to its high security.     

α‐Glucosidase Inhibitors from the Fungus Aspergillus terreus 3.05358

One new diketopiperazine alkaloid amauromine B ( 1 ), along with three known meroterpenoids, austalide B ( 2 ), austalides N and O ( 3 and 4 ), and two known steroids ( 5 and 6 ), was isolated and identified from the culture broth of the fungus Aspergillus terreus 3.05358. Their structures were elucidated by extensive spectroscopic techniques, including 2D‐NMR and MS analysis, the absolute configuration of 1 was unambiguously established by single crystal X‐ray diffraction analysis. All the isolates were evaluated for their inhibitory effects on α‐glucosidase. Amauromine B ( 1 ) and austalide N ( 3 ) exhibited more potent α‐glucosidase inhibitory activities than the positive control acarbose.     

Identifying the patterns of changes in α‐ and β‐diversity across Dacrydium pectinatum communities in Hainan Island,China

Exploring vegetation distribution spatial patterns facilitates understanding how biodiversity addresses the potential threat of future climate variability, especially for highly diverse and threatened tropical plant communities, but few empirical studies have been performed. Dacrydium pectinatum is a constructive and endangered species in the tropical mountain forests of Hainan Island, China. In this study, sixty‐eight 30 m × 30 m permanent plots of D. pectinatum were investigated, and species‐based and phylogenetic‐based methods were used to analyze the α‐ and β‐diversity pattern variation and its key drivers. Our study showed that species and phylogenetic α‐diversity patterns are different on a local scale. However, on a regional scale, the variations in the two α‐diversity patterns tend to converge, and they decrease with increasing elevation. The phylogenetic structure changes from overdispersion to convergence with increasing elevation. Soil (SOM, TP, AP), topography (EL, SL), and stand (CD) factors and α‐diversity showed close correlations. Species and phylogenetic β‐diversity have significant positive correlations with changing environmental distance and geographical distance; however, as a representative form of habitat heterogeneity, elevation distance has a greater impact on β‐diversity changes than geographical distance. In conclusion, the α‐ and β‐diversity patterns of the D. pectinatum community are mainly related to habitat filtering, especially in high‐elevation areas, and the colonization history of various regions also affects the formation of diversity patterns. Species‐based and phylogenetic‐based methods robustly demonstrated the key role of the habitat filtering hypothesis in community assembly. We believe that more plant diversity patterns need to be explored to understand the biodiversity formation mechanisms in tropical forests. We also recommend strengthening the construction and management of nature reserves to help address the biodiversity loss crisis in endangered tropical plant communities.     

Fatty acid composition and the characterization of a novel dioxo C18-fatty acid in the latex of Hevea brasiliensis

The fatty acids of the triacylglycerol fraction of the latex of the rubber plant consists of 97% of a C₁₈ furanoid fatty acid, 10,13-epoxy-11-methyloctadeca-10,12-dienoic. The free fatty acid fraction is composed of a more equally distributed mixture of 16:0, 18:0, 18:1, 18:2 and the furanoid acid. A novel dioxo fatty acid, 10,13-dioxo-11-methyloctadecanoic, was also isolated and characterized.     

褪黑素抗肿瘤机制的研究进展

褪黑素是新近引起人们广泛注意的天然抗肿瘤药物，对多种恶性或良性肿瘤具有明显抑制作用。其抗瘤机制复杂而广泛，主要包括调节雌激素作用通路，影响细胞周期，调节生长因子，干扰钙调素和微管蛋白功能，增加细胞间缝隙连接，对细胞代谢的影响以及抗氧化作用和免疫增强作用等。对于褪黑素作用机制的全面了解将有助于其进一步应用于临床。