基于射波刀Xsight spine prone tracking模式治疗脊柱肿瘤患者的摆位准确性分析

目的:射波刀脊柱肿瘤治疗提供了两种追踪模式,即脊柱追踪系统(Xsight spine tracking,XST)和俯卧位脊柱追踪系统(Xsight spine prone tracking,XSPT)。本研究通过比较两种脊柱追踪模式的摆位误差,评估射波刀采用XSPT模式治疗脊柱肿瘤患者的摆位准确性。方法:回顾性分析2020年7月至2021年6月在北京大学第三医院行射波刀治疗的腰骶脊柱肿瘤患者18例,分别采用仰卧位(真空垫固定)和俯卧位(热塑体网与俯卧板固定)进行CT模拟定位。按照XST与XSPT两种追踪方式设计治疗计划,治疗中分别记录两种体位脊柱追踪的摆位修正误差,平移修正为进出、左右、升降方向,角度修正为顺时针-逆时针旋转、仰俯、倾斜。同时采集俯卧位治疗模式下同步呼吸追踪的相关误差。两种追踪模式的摆位修正误差参数通过配对t检验方法进行分析,比较两组修正误差的差异。同时分析俯卧位同步呼吸相关误差,评估呼吸模型的预测准确性。结果:升降方向仰卧位修正误差为(0.18±0.16)mm,俯卧位为(0.31±0.26)mm,差异具有统计学意义(P<0.05);进出方向仰卧位修正误差为(0.27±0.24)mm,俯卧位为(0.50±0.40)mm,差异具有统计学意义(P<0.05)。俯卧位呼吸模型相关误差左右、进出和升降的平均值分别为(0.21±0.11)mm、(0.41±0.38)mm和(0.68±0.42)mm。结论:治疗中受呼吸运动的影响,相比于仰卧位定位方式,俯卧位在升降与进出方向摆位误差相对较大,但俯卧位治疗方式具有同步呼吸追踪系统,且该系统可以实现治疗过程中呼吸动度的实时修正。俯卧位脊柱追踪模式的一致性与准确性同样能够满足临床治疗需求。

Assessment of Temperature Extremes in China Using RegCM4 and WRF

This study assesses the performance of temperature extremes over China in two regional climate models(RCMs),RegCM4 and WRF, driven by the ECMWF's 20 th century reanalysis. Based on the advice of the Expert Team on Climate Change Detection and Indices(ETCCDI), 12 extreme temperature indices(i.e., TXx, TXn, TNx, TNn, TX90 p, TN90 p,TX10 p, TN10 p WSDI, ID, FD, and CSDI) are derived from the simulations of two RCMs and compared with those from the daily station-based observational data for the period 1981–2010. Overall, the two RCMs demonstrate satisfactory capability in representing the spatiotemporal distribution of the extreme indices over most regions. RegCM performs better than WRF in reproducing the mean temperature extremes, especially over the Tibetan Plateau(TP). Moreover, both models capture well the decreasing trends in ID, FD, CSDI, TX10 p, and TN10 p, and the increasing trends in TXx, TXn, TNx, TNn, WSDI, TX90 p,and TN90 p, over China. Compared with observation, RegCM tends to underestimate the trends of temperature extremes,while WRF tends to overestimate them over the TP. For instance, the linear trends of TXx over the TP from observation,RegCM, and WRF are 0.53?C(10 yr)^(-1), 0.44?C(10 yr)^(-1), and 0.75?C(10 yr)^(-1), respectively. However, WRF performs better than RegCM in reproducing the interannual variability of the extreme-temperature indices. Our findings are helpful towards improving our understanding of the physical realism of RCMs in terms of different time scales, thus enabling us in future work to address the sources of model biases.

Regulatory effect of salicylic acid and methyl jasmonate supplementation on ergosterol production in Hericium erinaceus mycelia

We evaluated the biomass and ergosterol content of Hericium erinaceus mycelium, and extracellular enzyme activities in H. erinaceus liquid culture following salicylic acid（SA） and methyl jasmonic acid（Me JA）supplementation. The optimal SA concentration was100 lmoláL-1, where the highest ergosterol content of 2.33 mgág-1was obtained following 6-day cultivation with100 lmoláL-1SA supplementation, and which was significantly higher than the unsupplemented control（p ／ 0.01）. Following 4-day supplementation with50 lmoláL-1Me JA, the highest ergosterol content obtained was 1.988 mgág-1, which was 25.8 % higher than the unsupplemented control. Our data indicate that SA and Me JA supplementation improves ergosterol content in H.erinaceus mycelium.

The Linkage between Two Types of El Ni?o Events and Summer Streamflow over the Yellow and Yangtze River Basins

It is generally agreed that El Nino can be classified into East Pacific(EP)and Central Pacific(CP)types.Nevertheless,little is known about the relationship between these two types of El Ni?o and land surface climate elements.This study investigates the linkage between EP/CP El Ni?o and summer streamflow over the Yellow and Yangtze River basins and their possible mechanisms.Over the Yellow River basin,the anomalous streamflow always manifests as positive(negative)in EP(CP)years,with a correlation coefficient of 0.39(-0.37);while over the Yangtze River basin,the anomalous streamflow shows as positive in both EP and CP years,with correlation coefficients of 0.72 and 0.48,respectively.Analyses of the surface hydrological cycle indicate that the streamflow is more influenced by local evapotranspiration(ET)than precipitation over the Yellow River basin,while it is dominantly affected by precipitation over the Yangtze River basin.The different features over these two river basins can be explained by the anomalous atmospheric circulation,which is cyclonic(anticyclonic)north(south)of 30°N over East Asia.EP years are dominated by two anticyclones,which bring strong water vapor convergence and induce more precipitation but less ET,and subsequently increase streamflow and flooding risks.In CP years,especially over the Yellow River basin,two cyclones dominate and lead to water vapor divergence and reduce moisture arriving.Meanwhile,the ET enhances mainly due to local high surface air temperature,which further evaporates water from the soil.As a result,the streamflow decreases,which will then increase the drought risk.

Alcohols Extraction Process and Content of Active Ingredients in Chinese Northeastern Auricularia auricula

[Objectives] The aim was to study the type and content of alcohol-soluble active ingredients in Auricularia auricula. [Methods]With total yield of alcohol extract as an indicator,the optimal concentrations of ethanol,isopropanol and n-butanol for alcohol extraction of A. auricula powder were determined. The contents of total flavonoids,polyphenols and triterpenoids in three different alcohol extracts of A. auricula,as well as in the alcohol extracts of polysaccharides and melanin extraction residue of A. auricula were determined. [Results] When90% ethanol was used,the yield of alcohol extract of A. auricula was 10. 7%. In the alcohol extract,the contents of total flavonoids,polyphenols and triterpenoids were 5. 68 mg/100 g,0. 43% and 0. 55%,respectively. When 100% isopropanol was used,the yield of alcohol extract was 10. 1%. In the alcohol extract,the contents of total flavonoids,polyphenols and triterpenoids were 4. 84 mg/100 g,0. 66% and 0. 37%,respectively. When 70% n-butanol was used,the yield of alcohol extract was 5. 4%. In the alcohol extract,the contents of total flavonoids,polyphenols and triterpenoids were 4. 07 mg/100 g,1. 68% and 0. 30%,respectively. The yields of ethanol,isopropanol and n-butanol extracts of polysaccharide and melanin extraction residue of A. auricula were 13. 8%,14. 3% and 8. 9%,respectively. In the three kinds of alcohol extracts,the contents of total flavonoids were 8. 28,11. 99,and 12. 38 mg/100 g,respectively; the contents of polyphenols were 0.14%,0. 38% and 0. 75%,respectively; and the contents of triterpenoids were 0. 25%,0. 60% and 0. 58%,respectively. [Conclusions]This study will provide certain reference for the in-depth study and development and utilization of active ingredients in A. auricula.

Homogenization of the Daily Land Surface Temperature over the Mainland of China from 1960 through 2017

Land surface temperature(LST)is one of the most important factors in the land-atmosphere interaction process.Raw measured LSTs may contain biases due to instrument replacement,changes in recording procedures,and other non-climatic factors.This study attempts to reduce the above biases in raw daily measurements and achieves a homogenized daily LST dataset over China using 2360 stations from 1960 through 2017.The high-quality land surface air temperature(LSAT)dataset is used to correct the LST warming biases especially evident during cold months in regions north of 40ºN due to the replacement of observation instruments around 2004.Subsequently,the Multiple Analysis of Series for Homogenization(MASH)method is adopted to detect and then adjust the daily observed LST records.In total,3.68×10^(3) effective breakpoints in 1.65×106 monthly records(about 20%)are detected.A large number of these effective breakpoints are located over large parts of the Sichuan Basin and southern China.After the MASH procedure,LSTs at more than 80%of the breakpoints are adjusted within+/-0.5℃,and of the remaining breakpoints,only 10%are adjusted over 1.5℃.Compared to the raw LST dataset over the whole domain,the homogenization significantly reduces the mean LST magnitude and its interannual variability as well as its linear trend at most stations.Finally,we perform preliminary analysis upon the homogenized LST and find that the annual mean LST averaged across China shows a significant warming trend[0.22℃(10 yr)^(-1)].The homogenized LST dataset can be further adapted for a variety of applications(e.g.,model evaluation and extreme event characterization).

Physical dosimetric reconstruction of a case of large area back skin injury due to overexposure in an interventional procedure

To estimate the physical dose of skin and key organs in a case of overexposure during a cardiac interventional procedure.Methods The female patient aged 50 suffered from owerexposure during ardiac interventional therapy in a hospital,Xinxiang city,Henan province,China in January 2020.The mesh-type phantom for the patient was constructed based on the adult mesh-type reference computational phantoms(MRCPs)released by the International Comission on Radiological Protection Publication 145 (ICRP145)and phantom deformation technology.Models of exposure scenario were constructed and simulated with particle and heavy ion transport code system(PHTTS)according to exposure conditions.Resuts:The maximum absorbed dose of key organs/tissues under iradiation in posteroanterior(PA)and 30°left anterior oblique directions(LOA)was 632.4 and 305.6 mGy,respectively.The let lung,heart,and left mammary gland received a larger dose under both iradiation conditions.The ratio of the absorbed dose with and without shielding was a lculated,and the relative difference in most organs was<1%between two directions.The iso-dose curve of the back skin revealed the ditribution of the absorbed dose(0.1-5.2 Gy).The dose estimate of key tssues/organs was higher than the conventional level,especially the local skin,up to 5.2 Gy.Concusions The interventional procedure in this ase resulted in a higher dose.Monte Carlo codes combined with the MRCPs can be employed to estimate physical dose to individuals in concrete irradia tion scenarios.