The Lyman-alpha Solar Telescope(LST) for the ASO-S mission——Ⅱ. design of LST

As one of the three payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is composed of three instruments:a Solar Corona Imager(SCI),a LyαSolar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST).When working in-orbit,LST will simultaneously perform high-resolution imaging observations of all regions from the solar disk to the inner corona up to 2.5 R⊙(R⊙stands for the mean solar radius)with a spatial resolution of 4.8′′and 1.2′′for coronal and disk observations,respectively,and a temporal resolution of 30–120 s and 1–120 s for coronal and disk observations,respectively.The maximum exposure time can be up to20 s due to precise pointing and image stabilization function.Among the three telescopes of LST,SCI is a dual-waveband coronagraph simultaneously and independently observing the inner corona in the HI Lyα(121.6±10 nm)line and white light(WL)(700±40 nm)wavebands by using a narrowband Lyαbeam splitter and has a field of view(FOV)from 1.1 to 2.5 R⊙.The stray-light suppression level can attain<10^-6 B⊙(B⊙is the mean brightness of the solar disk)at 1.1 R⊙and≤5×10^-8 B⊙at 2.5 R⊙.SDI and WST are solar disk imagers working in the Lyαline and 360.0 nm wavebands,respectively,which adopt an off-axis two-mirror reflective structure with an FOV up to 1.2 R⊙,covering the inner coronal edge area and relating to coronal imaging.We present the up-to-date design for the LST payload.

Genetic characteristics of a patient with multiple primary cancers:A case report

BACKGROUND Two or multiple primary malignant neoplasms(MPMNs)rarely occur in the same patient.It has been reported that MPMNs are easily misdiagnosed as the recurrence or metastasis of malignancies in clinical practice,affecting the choice of treatment for the patients,thereby resulting in the delay of optimal diagnosis.Next generation sequencing(NGS)can be used to distinguish between multiple primary lung cancers and intrapulmonary metastasis,and may distinguish the origin of tumours in different sites of the body.CASE SUMMARY We report the case of 66-year-old woman who suffered from different malignant neoplasms in the rectum and esophageal and gastrointestinal tract.The first neoplasm rectal adenocarcinoma was diagnosed and removed in 2016.The second and third lesions were diagnosed with esophageal squamous-cell carcinoma(ESCC)and gastrointestinal stromal tumour(GIST),respectively,in 2019.Nextgeneration whole exome sequencing was performed on the tissue specimens of rectal carcinoma,esophageal cancer,GIST,and white blood cells to investigate the relationship between malignancies at different timeframe and determine whether the ESCC and GIST evolved from the rectal adenocarcinoma.Mutations including v-Ki-ras2-Kirsten rat sarcoma viral oncogene homolog,adenomatosis polyposis coli,and mothers against decapentaplegic homolog 4 were detected in rectal adenocarcinoma sample,mast/stem cell growth factor receptor was detected in GIST tissue,and lysine methyltransferase 2D was detected in ESCC specimen.Overall,ESCC and GIST were not genetically evolved from rectal adenocarcinoma,and this patient did not have a trunk driven clone.CONCLUSION NGS is an effective tool to study clonal evolution of tumours and distinguish between MPMNs and intrapulmonary metastasis.

Corrosion resistance of BN-ZrO_(2)ceramics with different additives by molten steel

BN–ZrO_(2)ceramics with different additives such as SiC,Al_(2)O_(3) and MgAl_(2)O_(4) were fabricated by hot pressing sintering process to study sintering properties and corrosion resistance by the rotary immersion molten steel test.The results showed that SiC,Al_(2)O_(3) and MgAl_(2)O_(4) can improve the sintering properties of BN–ZrO_(2)ceramics;especially,the introduction of SiC can significantly improve the hardness of the material;thus,the above compounds will help to improve the wear resistance of BN–ZrO_(2)ceramics.The exposed oxide layer is in contact with molten steel and forms liquid phase after BN oxidation and B_(2)O_(3) volatilization,additives can significantly affect the properties of liquid phase,and m-ZrO_(2)grains are sintered and grown by dissolution–precipitation mechanism by liquid phase.Consequently,Al_(2)O_(3) and MgAl_(2)O_(4) are more conducive to the formation of working layer with solid skeleton,which determines the corrosion resistance of BN–ZrO_(2)ceramics.