Effects of spaceflight and simulated microgravity on microbial growth and secondary metabolism

Spaceflight and ground-based microgravity analog experiments have suggested that microgravity can affect microbial growth and metabolism. Although the effects of microgravity and its analogs on microorganisms have been studied for more than 50 years, plausible conflicting and diverse results have frequently been reported in different experiments, especially regarding microbial growth and secondary metabolism. Until now, only the responses of a few typical microbes to microgravity have been investigated; systematic studies of the genetic and phenotypic responses of these microorganisms to microgravity in space are still insufficient due to technological and logistical hurdles. The use of different test strains and secondary metabolites in these studies appears to have caused diverse and conflicting results. Moreover, subtle changes in the extracellular microenvironments around microbial cells play a key role in the diverse responses of microbial growth and secondary metabolisms. Therefore, "indirect" effects represent a reasonable pathway to explain the occurrence of these phenomena in microorganisms. This review summarizes current knowledge on the changes in microbial growth and secondary metabolism in response to spaceflight and its analogs and discusses the diverse and conflicting results. In addition, recommendations are given for future studies on the effects of microgravity in space on microbial growth and secondary metabolism.

论Manned Spaceflight的文体特征及其翻译策略——以被动句为研究案例

Manned Spaceflight一文陈述客观准确,逻辑结构严密,专业术语性强,语气正式。其文体特征包括被动语态、名词化、非谓语、专业词汇、割裂、并列、无灵主语、介词、长句、省略等。以被动句为例,通过Manned Spaceflight中翻译实践发现,被动句翻译为主动句、被动句和无主句时,翻译策略各不相同。

Analyses on schedule-cost coefficient correlation of spaceflight project based on historical statistics and its application

When analyze the uncertainty of the cost and the schedule of the spaceflight project, it is needed to know the value of the schedule-cost correlation coefficient. This paper deduces the schedule distribution, considering the effect of the cost, and proposes the estimation formula of the correlation coefficient between the in（schedule） and the cost. On the basis of the fact and Taylor expansion, the relation expression between the schedule-cost correlation coefficient and the in-schedule-cost correlation coefficient is put forward. By analyzing the value features of the estimation formula of the in-schedule-cost correlation coefficient, the general rules are proposed to ascertain the value of the schedule-cost correlation coefficient. An example is given to demonstrate how to approximately amend the schedule-cost correlation coefficient based on the historical statistics, which reveals the traditional assigned value is inaccurate. The universality of this estimation method is analyzed.

Mutagenic Effects of Spaceflight Treatment on the Second-Generation Seeds of Alfalfa

[ Objective] To explore the effects of spaceflight on the second-generation seeds of alfalfa and provide a theoretical basis for mutation breeding. [Method] The seeds of Medicago stavia L. lines no. 1, no. 2 and no. 4 were carried into space by the Shijian-8 seed breeding satellite for a 15-d spaceflight treatment. After returning to the ground, seedlings were transplanted to field. Traits of the second-generation seeds of alfalfa were evaluated. [Result] The 1 000-grain weight of the second-generation seeds were 5% -9% significantly higher than that the control （P 〈 0.05）. The germination rate, seedling weight, shoot length and root length were significantly increased （P 〈 0.05）. The hard seed rate and the rate of moldy seeds were significantly decreased （ P 〈 0.05）. However, the rate of dead seeds was increased. [ Conclusion] Spaceflight treatment has positive mutagenic effects on the second-generation seeds of alfalfa.

Speed kills: Highly relativistic spaceflight would be fatal for passengers and instruments

Highly relativistic speeds are desirable for interstellar travel. Relativistic time dilation would reduce the subjective duration of the trip for the travelers, so that they can cover galaxy-scale distances in a reasonable amount of personal time. Unfortunately, as spaceship velocities approach the speed of light, interstellar hydrogen H, although only present at a density of approximately 1.8 atoms/cm3, turns into intense radiation that would quickly kill passengers and destroy electronic instrumentation. In addition, the energy loss of ionizing radiation passing through the ship’s hull represents an increasing heat load that necessitates large expenditures of energy to cool the ship. Stopping or diverting this flux, either with material or electromagnetic shields, is a daunting problem. Going slow to avoid severe H irradiation sets an upper speed limit of v ~ 0.5 c. This velocity only gives a time dilation factor of about 15%, which would not substantially assist galaxy-scale voyages. Diffuse interstellar H atoms are the ultimate cosmic space mines and represent a formidable obstacle to interstellar travel.

Manned Spaceflight Ancient Dream, Modern Attempt

China was first in the world to invent rockets, and the first "astronaut" was also Chinese. In the late 14th century a man named Wanhu had himself tied to a special chair, the back of which was fitted with 47 prototype rockets, while

Estimation Method of Schedule-cost Correlation Coefficient of Spaceflight Project

To evaluate the cost risk and the schedule risk of the spaceflight project,the schedule-cost(S-C) correlation coefficient is directly appointed according to the experts' experience usually.This paper deduces SDMCU(the schedule distribution model considering the effect of the cost uncertainty),and then proposes the approximate formula to estimate the ln(S)-C correlation coefficient based on the models of SDMCU and CDMSU(the cost distribution model considering the effect of the schedule uncertainty).Furthermore,an approximate relationship expression of the S-C and the ln(S)-C correlation coefficients is put forward according to general facts and the Taylor expansion,and advanced by means of mass numerical validation is the general rule of obtaining the estimation value of the schedule-cost correlation coefficient based on the historical data.

Remarkable Achievements of China’s Manned Spaceflight Project

On September 21,1992, the feasibility report on implementing China's Manned Spaceflight Project was approved and a three-step development strategy was also determined. From then on, China's Manned Spaceflight Project has developed rapidly.

LM-2F: A Great Launch Vehicle for China's Manned Spaceflight

The LM-2F launch vehicle is China's first launch carrier developed for China's Manned Space Program,which is one of the most important parts of the Program.It is developed from the LM-2E launch vehicle,with addition of two new systems,an escape system and a fault detection system.

关于“Some Theoretical Problems of the Spaceflight Mechanics”(Ⅲ)

改善了文献［２］的前言

关于“Some Theoretical Problems of the Spaceflight Mechanics” (Ⅳ)

本文完善了文献［１］的一些结果。

Genome and clonal hematopoiesis stability contrasts with immune,cfDNA,mitochondrial,and telomere length changes during short duration spaceflight

Background The Inspiration4(I4)mission,the first all-civilian orbital flight mission,investigated the physiological effects of short-duration spaceflight through a multi-omic approach.Despite advances,there remains much to learn about human adaptation to spaceflight's unique challenges,including microgravity,immune system perturbations,and radiation exposure.Methods To provide a detailed genetics analysis of the mission,we collected dried blood spots pre-,during,and post-flight for DNA extraction.Telomere length was measured by quantitative PCR,while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations.A robust bioinformatic pipeline was used for data analysis,including variant calling to assess mutational burden.Result Telomere elongation occurred during spaceflight and shortened after return to Earth.Cell-free DNA analysis revealed increased immune cell signatures post-flight.No significant clonal hematopoiesis of indeterminate potential(CHIP)or whole-genome instability was observed.The long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months post-flight.Conclusion Our findings provide valuable insights into the physiological consequences of short-duration spaceflight,with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to Earth.CHIP sequencing data will serve as a reference point for studying the early development of CHIP in astronauts,an understudied phenomenon as previous studies have focused on career astronauts.This study will serve as a reference point for future commercial and non-commercial spaceflight,low Earth orbit(LEO)missions,and deep-space exploration.

自修复弹性体材料的研究进展及应用

综述了基于外援型和本征型2种体系的弹性体材料自修复机理和自修复技术在弹性体材料中的应用,并展望了自修复弹性体材料在载人航天领域的应用前景。

载人航天人机交互界面色彩设计方法研究

目的对载人航天人机交互界面的色彩设计方法流程进行了梳理和分析。方法遵循“以人为中心”的设计原则,从色彩空间与模型、色彩设计与人因、航天色彩设计范围、载人航天器色彩设计模型,以及载人航天器色彩设计与人因评价体系等方面,对载人航天器人机交互界面色彩设计方法流程体系进行了探讨。结果构建了载人航天色彩设计模型,阐述了完整的载人航天色彩设计方法流程体系。结论针对载人航天人机交互色彩设计方法的研究为航天员在轨环境中的生活品质及工作效能等相关领域的提高提供了有力支持,进一步增强了航天领域色彩设计与人因工程的重要性。

载人航天商业化的国际损害责任制度:困境与应对

载人航天商业化的发展需要平衡外层空间的公共性和商业载人航天的私营性,国际损害责任制度对管控商业载人航天的成本和风险至关重要。国际外空法对国际损害责任进行了一般性、原则性规定,部分航天国家在国内法中对商业载人航天的损害责任予以明确。基于外空领域的现有责任规则,构建国际损害责任制度面临着责任主体和索赔主体不明、过失作为例外要件存在不合理、国际保险标准难统一、责任分配制度待完善的困境。对此,可考虑通过关联性确认责任主体和索赔主体、对损害统一适用绝对责任、引入强制责任保险、形成双重责任制度,为国家载人航天商业化发展提供制度构建思路;同时,促进国际社会达成共识,推动人类命运共同体理念在外空领域的进一步实现。

航天诱变育种对金针菇遗传和药用品质性状的影响

[目的]本文旨在利用航天诱变技术,选育获得金针菇特色优质种质资源。[方法]对金针菇菌株F3-1进行航天诱变处理,通过拮抗试验、分子标记试验和活性物质测定等对航天诱变菌株进行筛选鉴定及遗传变异多样性分析,并筛选活性物质含量高的菌株。[结果]拮抗试验初筛获得7株与出发菌株存在拮抗现象的变异株。分子标记(ISSR、RAPD、SRAP)聚类分析结果表明,7个诱变菌株与出发菌株的遗传相似系数为0.694~0.962,且在遗传相似系数为0.800时可分为3个类群。诱变菌株与出发菌株的菌丝生长速度、生物量、总酚、类黄酮、多糖和麦角硫因等指标的变异系数为7.68%~38.97%,遗传多样性指数H′为1.53~2.00。其中,多糖含量的变异系数最高,受诱变影响大;总酚的遗传多样性指数最大,诱变类型丰富。生物学特性聚类分析显示,在遗传距离为3.16时分为3个类群。最终筛选获得2株活性物质含量高的菌株(T2和T5),其中T2菌株生长速度、生物量和活性物质等均优于出发菌株,而T5菌株主要表现为高多糖含量菌株,其多糖含量比出发菌株提高114.70%(P<0.01)。[结论]航天诱变处理的金针菇菌株存在丰富的遗传变异多样性,是新品种选育的优异种质资源。

Physiological effects of weightlessness: countermeasure system development for a long-term Chinese manned spaceflight

The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness.

一种适用于载人航天飞行的针织手套设计及性能分析

针对载人航天飞行任务中航天服配套的舒适手套,开展研究设计与样品试制,以传统的纯棉天然纤维与高性能的聚酰亚胺纤维2种材料织造的针织手套为对象,在力学性能、吸湿性、透气性、热传导性等方面进行比对实验与分析,同时针对聚酰亚胺在卫生学、远红外等原生特性方面开展实验验证。结果表明:相对于棉针织手套,聚酰亚胺针织手套的力学性能与热稳定性更优,使用过程中脱出物更少,对载人航天飞行应用的环境更加友好;基于聚酰亚胺纤维的低吸湿与低导热特性,在航天服内部人手出汗与环境温度变化下的干湿态转换过程中,针织手套的性能损失较小;聚酰亚胺纤维原生性的远红外特性与抗菌抑菌能力能够为针织手套在肢体末端湿冷环境下提供更好的温热性与卫生学满足性。

2023年国外载人航天发展初步分析

2023年,国外载人航天继续稳步发展。美国继续大力推进阿尔忒弥斯月球探测计划,稳步布局国际空间站2030年后的发展;俄罗斯积极规划载人登月与未来月球基地发展,筹划新轨道空间站建设。欧洲谋求发展独立的载人航天能力,将以货运飞船为基础研制载人飞船。印度积极推动首次载人航天飞行任务准备,并明确空间站与载人登月任务。商业载人航天继续快速发展,成为更多国家开展载人航天活动的主要渠道。国际空间站投入运营已满25年,在推动深空载人探索技术与地球科学技术发展等方面将发挥更大作用。

IM公司奥德修斯号月面着陆器任务浅析

针对M公司的Nova-C级月面着陆器奥德修斯号开展了分析,从整器构型、飞行过程、载荷配置、任务评价4个方面进行了介绍,并对此次任务中遇到的故障以及处置措施进行了梳理,剖析了商业航天的特征,最后总结了商业航天运营模式对于我国航天事业发展的启示,以及本次飞行任务中的亮点和故障情况对我国月球探测任务的启示,并给出了几点思考与建议。