Chemoselective labeling-based spermatozoa glycan imaging reveals abnormal glycosylation in oligoasthenotspermia

Spermatogenesis, maturation, capacitation and fertilization are precisely regulated by glycosylation. However, the relationship between altered glycosylation patterns and the onset and development of reproductive disorders is unclear, mainly limited by the lack of in situ imaging techniques for spermatozoa glycosylation. We developed an efficient and highly specific spermatozoa glycan imaging technique based on the robust chemoselective labeling of sialic acid(Sia) and N-acetyl-D-galactosamine(Gal/GalNAc). We further proposed a “tandem glycan chemoselective labeling” strategy to achieve simultaneous imaging of two types of glycans on spermatozoa. We applied the developed method to the spermatozoa from oligozoospermic patients and diabetic mice and found that these spermatozoa showed higher levels of Sia and Gal/Gal NAc expression than the normal groups. Moreover, spermatozoa from diabetic mice showed a severe decrease in number, viability, and forward motility, suggesting that in vivo glucose metabolism disorders may lead to an elevated level of spermatozoa glycosylation and have a correlation with the development of oligoasthenotspermia. Our work provides a research tool to reveal the relationship between glycosylation modification and spermatozoa quality, and a promising clue for the development of glycan-based reproductive markers.

Linking coral fluorescence phenotypes to thermal bleaching in the reef-building Galaxea fascicularis from the northern South China Sea

Coral fluorescence phenotypes have been suggested as an adaptation to a broad range of environmental conditions,yet the mechanisms linking thermal bleaching tolerance in reef-building coral populations,associated with fluorescence phenotypes due to GFP-like proteins,remains unclear.In this study,the relationship between the thermal sensitivity and phenotypic plasticity of corals was investigated using two phenotypes of Galaxea fascicularis,green and brown.The results reveal that brown G.fascicularis was more susceptible to bleaching than green G.fascicularis when exposed to a higher growth temperature of 32℃.Both phenotypes of G.fascicularis were associated with the thermotolerant Symbiodiniaceae symbiont,Durusdinium trenchii.However,the brown G.fascicularis showed a significant decrease in Symbiodiniaceae cell density and a significant increase in pathogenic bacteria abundance when the growth temperature was raised from 29 to 32℃.The physiological traits and transcriptomic profiles of Symbiodiniaceae were not notably affected,but there were differences in the transcriptional levels of certain genes between the two phenotype hosts of G.fascicularis.Under heat stress of 32℃,the gene encoding green fluorescent protein(GFP)-like and chromosome-associated proteins,as well as genes related to oxidative phosphorylation,cell growth and death showed lower transcriptional levels in the brown G.fascicularis compared to the green G.fascicularis.Overall,the results demonstrate that the green form of G.fascicularis is better able to tolerate ocean warming and defend against pathogenic bacteria,likely due to higher gene transcription levels and defense ability.

Simultaneous optimization of conduction and polarization losses in CNT@NiCo compounds for superior electromagnetic wave absorption

Polarization and conduction losses are the two most crucial dielectric loss mechanisms for carbon-based composites,but their synergistic effects in different frequency bands need to be further revealed.More importantly,for polarization and conduction losses,the strengthening of one party always comes at the expense of the other,which inevitably limits the overall performance of the absorbers.Herein,we have developed a composite of CNT and NiCo hybrid particles via a scalable wet chemical process and an-nealing method.Through the adjustment of the precursor and the annealing temperature,the conduction and polarization losses of the composite are optimized simultaneously.The optimized samples achieved the full absorption of the X and Ku bands under conditions of low filling rate and thin thickness.Further theoretical and experimental studies have revealed conduction loss and polarization loss laws at different frequency ranges.The synergistic effect of conductive loss and magnetic loss in the low-frequency region ensures that the sample exhibits high microwave dissipation performance.However,in the medium and high-frequency part,the magnetic loss can be almost ignored and the timely replenishment of polar-ization loss keeps the wave-absorbing performance at a high level.The excellent multi-band absorption characteristics make the as-obtained absorbers meet the needs of future applications.

Research progress in the phytochemistry and biology of Ilex pharmaceutical resources

Ilex is a botanical source for various health-promoting and pharmaceutically active compounds that have been used in traditional Chinese medicine and food for thousands of years.Increasing interest in Ilex pharmaceutical and food resources has led to additional discoveries of terpenoids,saponins,polyphenols(especially flavonoids),glycosides,and many other compounds in various Ilex species,and to investigation of their chemotaxonomy,molecular phylogeny and pharmacol-ogy.In continuation of our studies on Ilex pharmacology and phylogeny,we review the phytochemistry,chemotaxonomy,molecular biology and phylogeny of Ilex species and their relevance to health-promotion and therapeutic efficacy.The similarity and dissimilarity between Ilex paraguariensis,the source plant of mate tea,and the source plants of large-leaved K udingcha(e.g.,Ilex kudingcha and Ilex latifolia)are discussed.It is essential to utilize emerging technologies in non-Camellia tea studies to promote the sustainable utilization of Ilex resources and the identification and development of novel compounds with potential health and clinical utility.Systems biology and "-omics"technologies will play an increasingly important role in pharmaceutical and food research on the bioactive compounds of Ilex species.

The Tianwen-1 Guidance, Navigation, and Control for Mars Entry, Descent, and Landing

Tianwen-1,the first mission of China’s planetary exploration program,accomplished its goals of orbiting,landing,and roving on the Mars.The entry,descent,and landing(EDL)phase directly determines the success of the entire mission,of which the guidance,navigation,and control(GNC)system is crucial.This paper outlines the Tianwen-1 EDL GNC system design by introducing the GNC requirements followed by presenting the GNC system architecture and algorithms to meet such requirements.The actual flight results for the whole EDL phase are also provided in this paper.

Corrigendum to “The Tianwen-1 Guidance, Navigation, and Control for Mars Entry, Descent, and Landing”

In the article titled“The Tianwen-1 Guidance,Navigation,and Control for Mars Entry,Descent,and Landing”[1],there was an error in Figure 9(b).On the y-axis,the data read q1,q2,and q1.It should have read q1,q2,and q3.This is updated as shown in Figure 1 below.