Illumination and regolith temperature at China's next candidate lunar landing site Shackleton crater

This study focuses on the illumination and temperature at China’s next lunar candidate landing site Shackleton crater.We used the NASA’s SPICE system to evaluate the terrain obscuration effect on real-time illumination;the resulting illumination map resembles previous studies,validating the methodologies used in our study.In addition,we estimated an accumulated illumination map for the period of likely rover movement.The map indicates the illuminated inner wall of the Shackleton crater is close to 27%of the whole,meaning that the rover will likely receive solar radiation during its movement.Using the real-time illumination and the distributed 1-D thermal diffusion model,we continuously evaluated the regolith temperature for more than 20 years to stabilize the temperature,and selected the temperature of the end time as the initial value used in a thermal study set for July 20,2023 and May 8,2027.Our results indicate the temperature in the permanent shadow region remains nearly constant,thus validating the stability of our estimated initial temperature.Our results also indicate that the surface temperature is more sensitive to transient illumination,but the subsurface temperature is more likely to be associated with the accumulated illumination.This difference indirectly implies that the conductivity of the lunar regolith is inefficient.The locations receiving more solar radiation show a temperature larger than the threshold(~112 K)of ice stability.The permanently shadowed regions can be as cold as 25 K,and such extreme coldness is a hazard to the rover.There are suitable temperature locations which have a warm surface but cold subsurface to preserve water ice.To further ensure normal rover movement,we provided a map of suitable temperature sites and found that these locations exist not only in the Shackleton crater’s inner wall,but also outside the crater.We suggested four trade-off sampling sites with suitable temperatures and gradual slopes.

Single-cell transcriptomics reveals cell type diversity of human prostate

Extensive studies have been performed to describe the phenotypic changes occurring during malignant transformation of the prostate.However,the cell types and associated changes that contribute to the development of prostate diseases and cancer remain elusive,largely due to the heterogeneous composition of prostatic tissues.Here,we conduct a comprehensive evaluation of four human prostate tissues by singlecell RNA sequencing(sc RNA-seq)to analyze their cellular compositions.We identify 18 clusters of cell types,each with distinct gene expression profiles and unique features;of these,one cluster of epithelial cells(Ep)is found to be associated with immune function.In addition,we characterize a special cluster of fibroblasts and aberrant signaling changes associated with prostate cancer(PCa).Moreover,we provide insights into the epithelial changes that occur during the cellular senescence and aging.These results expand our understanding of the unique functional associations between the diverse prostatic cell types and the contributions of specific cell clusters to the malignant transformation of prostate tissues and PCa development.

Developing Prototype Simulants for Surface Materials and Morphology of Near Earth Asteroid 2016 HO3

There are a variety of applications for asteroid simulants in asteroid studies for science advances as well as technology maturation.For specific purpose,it usually requires purpose-specialized simulant.In this study,we designed and developed a set of prototype simulants as S-type asteroid surface materials analogue based on H,L,and LL ordinary chondrites’mineralogy and terrestrial observations of near-earth asteroid 2016 HO3,which is the Chinese sample return mission target.These simulants are able to simulate morphology and reflectance characteristics of asteroid(469219)2016 HO3 and,thus,to be used for engineering evaluation of the optical navigation system and the sampling device of the spacecraft during the mission phase.Meanwhile,these prototype simulants are easily to modify to reflect new findings on the asteroid surface when the spacecraft makes proximate observations.