密闭系统中四种共培养植物光合作用效率研究

目的 探讨大型密闭系统中几种共培养植物的光合效率等特性,为开展人与植物的物质交换实验提供基础数据.方法 利用受控生态生保系统集成实验平台植物舱开展常压下生菜等4种共培养色拉型蔬菜的光合效率研究.植物共培养面积为36.0 m2;采用Hoagland营养液培养;光源为90％红+10％蓝LED组合光源,光照强度为450μmol·m-2·s-1PPF,光照周期为24 h;根据植物不同生长阶段调节CO2浓度,控制范围为0.2％ ～0.8％.结果 系统运行平稳,环境参数控制状态良好,植物生长状态基本正常;共培养植物产O2量和CO2吸收量平均分别为0.915 kg·d-1和1.204 kg·d-1,植物平均每天能产生约1.1人呼吸所需的O2,同时吸收其排出的CO2.结论 通过该实验,基本掌握植物共培养技术及系统放O2和吸收CO2的能力,可为开展多人多天的受控生态生保系统集成试验研究提供技术支持.     

受控环境中高CO_2浓度条件下油麦菜生长特性研究

目的研究植物在高大气CO2浓度下的生长特性,为空间受控生态生保系统选择生物部件提供依据。方法在受控环境中不同CO2浓度下培养油麦菜,综合评价不同处理下植株的生长状态、生理特性和养分含量。结果0.1%～1.0%CO2浓度能够促进油麦菜植株的光合和蒸腾速率、提高叶绿素和类胡萝卜素的含量,但更高浓度(1.5%～2.0%)CO2则会导致其下降;在0.1%～2.0%CO2浓度条件下,油麦菜植株能够基本正常生长,株高和叶面积都有所增加,但叶片数量却在下降;随着CO2浓度梯度增加,油麦菜植株中氮、钾和Vc的含量下降,磷的含量上升,而微量元素的含量没有明显差异。结论油麦菜植株在高CO2浓度下能够基本正常生长,没有受到严重抑制现象,具有较强耐高CO2浓度的能力,适宜作为受控生态生保系统中的候选生物部件。     

长效专用控释肥在受控生态生保系统中应用的实验研究

目的研究并验证长效专用控释肥料在受控生态生保系统中应用的可行性，为未来受控生态生保系统中高等植物的栽培提供合适的养分资源。方法在特定的光照、温度和大气等环境条件下，通过植物栽培实验，进行施肥、不施肥以及不同专用控释肥料品种的生菜培养，比较不同处理下植株的生长形态、测试并分析植株体内的各种营养组分等。结果在不施肥的条件下，植株不能正常生长，施肥能促进植株的正常生长发育；利用肥料1栽培的生菜植株品质好于肥料2栽培的生菜植株。结论所研制的长效控释专用肥料能在受控生态生保系统中应用，针对不同的植物品种应选用不同的肥料品种作为养分资源。     

受控生态环境小麦的生长发育动态及生物学特性

目的利用"绿航星际"4人180天受控生态生保系统(Controlled Ecological Life Support System,CELSS)试验平台,研究小麦在受控生态生保系统中的生长发育动态和生物学特性,为小麦植物部件在该系统的工程应用积累数据。方法对小麦(Wt03)全生育期不同生长天数的重要性状和生物量积累情况进行动态监测,并比较小麦在受控生态环境下与大田的生物学特性差异,全面观察和记录小麦在CELSS中的生长发育特性。结果从移栽后15 d到85 d,小麦的总生物量积累从209.15 g/m2增长到2379.59 g/m2,收获可食部分干重13.41 g/(m2·d)。相比大田环境,小麦在受控生态环境下的生育期相对缩短,其性状上株高明显变矮,单穗重下降,但旗叶变大,单株有效穗增多,产量比大田提高53%。结论该小麦品种在密闭系统中有良好的适应性,产量较高,适合用作受控生态生保系统生物部件。     

多年生叶类蔬菜在CELSS中的生产和品质分析

目的研究多年生叶类蔬菜在受控生态生保系统(Controlled Ecological Life Support System,CELSS)中的生长和生产情况。方法在绿航星际—4人180天CELSS集成试验中,引入4种多年生叶类蔬菜(绿背天葵、芹菜、韭菜和空心菜),通过对生长情况、生长速率以及营养成分等指标与生菜进行比较,分析多年生叶类蔬菜在CELSS中的应用前景。结果4种多年生叶类蔬菜在集成试验中生长状态良好;试验结束时,绿背天葵和空心菜可食部分生产速率高于生菜;多年生叶类蔬菜的收获间隔时间短,且营养成分与生菜相当。结论多年生叶类蔬菜具有管理简单、收获间隔短、产量稳定等特点,能够在未来长期深空探测或星球基地任务的生保系统构建中发挥重要作用。     

受控生态生保系统中C2H4去除装置的研制

目的 研制成C2H4去除装置,去除密闭环境植物生长过程中不断产生的微量C2H4气体,为受控生态生保系统大气控制提供有效的方法。方法 根据产品技术指标和性能要求,提出设计方案,并完成产品的加工、安装与调试,最后进行低浓度C2H4去除的验证试验。结果 该装置系统运行良好,其能耗、体积、降解C2H4能力等均满足设计要求。在气体流速为1．0～3．0L／min、相对湿度20％、灯源功率48W条件下,C2H4浓度从0．034mg／kg降至0．010mg／kg以下;从降解产物来看,除CO2和H2O外,基本上无其它有毒副产物产生。结论 该装置结构设计合理,C2H4去除效率高,可作为受控生态生保系统植物栽培体系中微量C2H4污染气体的去除装置。     

4人180天受控生态生保系统集成试验概述

4人180天受控生态生保系统集成试验是针对深空探测后续长期载人航天任务需求开展的关键技术预先性研究。该试验以未来月球或火星航天员基地受控生态生保系统的研制及其工程化为任务背景,在中国航天员科研训练中心长期实验室研究和初步系统集成试验研究的基础上开展的由4人乘组参与的集成要素多、封闭时间长、物质闭合度高的受控生态生保系统集成技术试验。试验系统引入受控生态概念,以生物再生为主要技术特征,有机融合物化再生技术和基础性环境控制技术,构建成适合多乘员长时间驻留的第三代载人航天环境控制与生命保障的试验系统。本文概述了试验平台基本情况、志愿者乘组情况、试验项目设置、试验条件控制、试验基本结果等内容,并初步讨论了受控生态生保系统集成试验的科学目标与未来发展前景。     

受控生态生保技术综合实验系统的研制

目的 建成受控生态生保技术综合实验系统,为下一步开展受控生态生保系统的整合实验和系统内物质闭合循环实验研究构建试验平台。方法 在大量方案调研、方案设计和图纸设计的基础之上,通过加工、安装和联合调试等技术手段来实现。结果 该系统容积约为40m^3,其舱内温度、相对湿度、氧浓度、二氧化碳浓度、总压、光照强度、光照周期、栽培基质水分含量和乙烯浓度等参数均得到有效控制,系统运行稳定;栽培系统包括左右两排,每排分为上下两层;栽培床总面积约为8．4m^3,其上下垂直距离电动可调;光源为红色和蓝色两种发光二极管的组合。结论 该试验平台的成功研制,为下一步开展大规模受控生态生保技术整合试验研究创造了必备条件。     

受控环境中二氧化碳浓度对生菜生长发育的影响

目的,研究受控生态生保系统中获得高产优质美湖包心生菜的二氧化碳高浓度极限值。方法 在新近建成的空间高等植物栽培地面实验装置中,进行了5批次不同二氧化碳浓度实验（2000－10000umol.mol^-1),其它诸多参数保持恒定。栽培期间进行了植株形态学观察,记录了每日二氧化碳添加量,营养液补充水添量和冷凝水收集量等,收获后进行了产量和光合效率计算及植物多种组分的分析等。结果 生菜在二氧化碳浓度为6000umol.mol^-1时栽培效果比较理想,8000umol.mol^-1时产量有所提高但品质略有下降,而当达到10000umol.mol^-1时则出现明显的中毒凋亡现象,此时产量和品质均极差。结论 在上述情况下,美湖包心生菜栽培舱内二氧化碳浓度最好控制在6000umol.mol^-1以内。     

南极植物生产系统概述与分析

植物是受控生态生保系统中的关键生物部件,可以为乘员提供食物、氧气和净水,同时可以起到一定的心理支持作用。世界各国/组织在南极开展了多年的植物生产系统研究和实施工作,研制了不同类型的植物生产系统。这些系统不仅为南极考察人员提供了一定的食物供给,也为推动受控生态生保系统的发展提供了技术支持和试验验证。本文总结和分析了南极曾经建设或现有的植物生产系统,对比分析了这些植物生产系统的建设目的、规模、类型和自动化程度等具体信息,并展望了南极植物生产系统未来的发展趋势。     

Prolonged constant load cycling exercise is associated with reduced gross efficiency and increased muscle oxygen uptake

This study investigated the effects of prolonged constant load cycling exercise on cycling efficiency and local muscle oxygen uptake responses. Fourteen well‐trained cyclists each completed a 2‐h steady‐state cycling bout at 60% of their maximal minute power output to assess changes in gross cycling efficiency (GE) and muscle oxygen uptake (mVO₂) at time points 5, 30, 60, 90, and 120 min. Near‐infrared spatially resolved spectroscopy (NIRS) was used to continually monitor tissue oxygenation of the Vastus Lateralis muscle, with arterial occlusions (OCC) applied to assess mVO₂. The half‐recovery time of oxygenated hemoglobin (HbO₂) was also assessed pre and post the 2‐h cycling exercise by measuring the hyperemic response following a 5‐min OCC. GE significantly declined during the 2‐h cycling bout (18.4 ± 1.6 to 17.4 ± 1.4%; P < 0.01). Conversely, mVO₂ increased, being significantly higher after 90 and 120 min than at min 5 (+0.04 mlO₂/min/100 g; P = 0.03). The half‐recovery time for HbO₂ was increased comparing pre and post the 2‐h cycling exercise (+7.1 ± 19s), albeit not significantly (d: 0.48; P = 0.27). This study demonstrates that GE decreases during prolonged constant load cycling exercise and provides evidence of an increased mVO₂, suggestive of progressive mitochondrial or contractile inefficiency.     

Real evaporative cooling efficiency of one‐layer tight‐fitting sportswear in a hot environment

Real evaporative cooling efficiency, the ratio of real evaporative heat loss to evaporative cooling potential, is an important parameter to characterize the real cooling benefit for the human body. Previous studies on protective clothing showed that the cooling efficiency decreases with increasing distance between the evaporation locations and the human skin. However, it is still unclear how evaporative cooling efficiency decreases as the moisture is transported from the skin to the clothing layer. In this study, we performed experiments with a sweating torso manikin to mimic three different phases of moisture absorption in one‐layer tight‐fitting sportswear. Clothing materials Coolmax^® (CM; INVISTA, Wichita, Kansas, USA; 100%, profiled cross‐section polyester fiber), merino wool (MW; 100%), sports wool (SW; 50% wool, 50% polyester), and cotton (CO; 100%) were selected for the study. The results demonstrated that, for the sportswear materials tested, the real evaporative cooling efficiency linearly decreases with the increasing ratio of moisture being transported away from skin surface to clothing layer (adjusted R² >0.97). In addition, clothing fabric thickness has a negative effect on the real evaporative cooling efficiency. Clothing CM and SW showed a good ability in maintaining evaporative cooling efficiency. In contrast, clothing MW made from thicker fabric had the worst performance in maintaining evaporative cooling efficiency. It is thus suggested that thin fabric materials such as CM and SW should be used to manufacture one‐layer tight‐fitting sportswear.     

葡萄糖修饰的载胰岛素脂质体以包封率为指标的制备工艺研究

目的基于乙醇对脂质双分子层膜的去稳定作用制备得较高包封率的载胰岛素脂质体。方法本研究以空白大单室脂质体在乙醇存在的条件下对胰岛素进行主动载药。考察了脂质处方、乙醇浓度、孵育温度、孵育时间、PEG2000-succ-Chol用量、药脂比等对包封率的影响。结果乙醇存在条件下空白大单室脂质体对胰岛素进行主动载药而得粒径（180±70）nm的小多室脂质体,包封率为28%～32%。结论该方法制备所得的胰岛素脂质体比文献报道的包封率提高了近2倍,而且避免了使用有机溶剂,最大程度保护了胰岛素的生物活性。     

Mechanical efficiency in athletes during running

The purpose of this study was to compare the external mechanical efficiency (ME) between power-trained athletes ( n = 5) and endurance-trained athletes ( n = 5). The relationships between biomechanical variables and metabolic cost were also investigated. The subjects ran at 3 different speeds (2.50 m · s⁻¹, 3.25 m · s⁻¹ and 4.00 m · s⁻¹) both on the treadmill and on the track. The external work of the subjects was determined by a kinematic arm, and energy expenditure was determined by measuring oxygen consumption and respiratory exchange ratio. Biomechanical parameters included ground reaction forces, angular displacements of the knee and ankle joints and electromyography (EMG) of the selected muscles. The mean ME (±SD) values during running on treadmill were as follows: 49.6±8.9%, 60.1±9.6% and 61.2±10.4% for the endurance group, and 47.1±3.7%, 52.0±4.3% and 57.4±5.5% for the power group. In running on the track the respective values were 57.5±11.9%, 51.5±6.1% and 62.2±9.2% for the endurance group, and 47.0±8.3%, 45.3±10.2% and 60.0±5.9% for the power group. The subject groups did not differ significantly in ME due to high interindividual variance among both subject groups. The metabolic responses such as heart rate, pulmonary ventilation and oxygen uptake differed clearly between the athletic groups but this was not the case for the most of the biomechanical variables (such as EMG, step length and vertical displacement of the centre of the gravity). In conclusion, physiological and biomechanical variables appear to affect ME in a very complex way. In other words, efficiency is related individually to the sum of many variables.     

体温过高时的头部致冷问题

体温过高时可采用个体调温装置进行全身或局部致冷。头部是有效的致冷区，有极高的致冷效率，但由于体表面积不大，对其致冷重要性的认识尚不一致。本文以实验事实为依据，系统论述了头部具有极好的致冷效果，应作为局部致冷的首选部位。尤其在航空活动中，头部致冷有着特殊重要的意义。文章还讨论了应注意的若干医学－工程学问题，以供工程设计参考。     

舰船人员人工种植牙疗效及相关因素评价

目的　探讨舰船环境对人工种植牙的影响因素 ,提高其临床成功率。方法　对 2 4例舰船人员 36颗改良术式法的 HA- Ti人工种植体 ,负重 1年后进行临床及 X线随访 ,并与同期 35例陆地人员的 4 7颗种植体对照。结果　舰船组临床成功率为 86 .11% ,低于陆地组的 93.6 2 % ,统计学差异无显著性 (P>0 .0 5 )。舰船组的菌斑指数 (PL I)明显高于地面组 (P<0 .0 5 )。龈沟出血指数 (SBI)和牙周治疗需要指数 (CPITN )两项指标 ,舰船组均明显高于陆地组 (P<0 .0 5 )。两组患者种植体和牙槽骨的骨性结合率 ,舰船组 (89.6 5 %± 11.32 % )略低于陆地组 (92 .12 %± 10 .5 6 % ) ,但无明显统计学意义 (P>0 .0 5 )。结论　人工种植牙可适用于舰船人员 ,但患者应着重提高口腔及牙周保健能力。     

Calibration of a radionuclide calibrator system as a Bulgarian standard for activity

A commercially available radionuclide calibrator of the type Curiementor 3 (PTW, Freiburg, Germany) was calibrated using activity standard solutions, from the Physikalisch-Technische Bundesanstalt (PTB), of a number of photon-emitting radionuclides, in particular those used in nuclear medicine: ¹⁸F, ⁵¹Cr, ⁶⁷Ga, ^99mTc, ¹¹¹In, ¹²³I, ¹²⁵I, ¹³¹I, ¹⁸⁶Re, ²⁰¹Tl, and for beta-emitting nuclides: ³²P, ⁸⁹Sr, ⁹⁰Y, ²⁰⁴Tl. An energy-dependent efficiency curve was established to calculate efficiencies for photon-emitting radionuclides. The differences between experimental and calculated radionuclide efficiencies of the measuring system are of the order of a few percent. The performance of the system was checked for instrument stability, using a long-lived ¹³⁷Cs source, and for linearity using the decay of a ^99mTc source. The calibration measurements were carried out with 2 g of solution in standard PTB-type glass ampoules. The dependence of efficiency with varying solution mass and changing ampoule geometry is studied for some of the radionuclides. For example, geometry correction factors are determined for various solution volumes or ampoules with different wall thickness. The measuring system will enable the National Centre of Metrology (NCM) of Bulgaria to provide calibration services for activity measurements, which are traceable to PTB standards, and to organize national comparisons in order to improve the quality of measurements for nuclear medicine in Bulgarian hospitals. Furthermore, it should enable NCM to declare Calibration and Measurement Capabilities (CMCs) and to submit radioactive solutions to the International Reference System (SIR) at the BIPM in order to compare the results with Key Comparison Reference Values (KCRVs).     

机械剪毛中羊只的保定及高效剪毛方式

剪毛是细毛羊标准化生产的重要环节,剪毛技术直接影响套毛的质量及价格。相比传统的手工剪毛方式,机械化剪毛方式具有速度快、产量高,质量好等优势,推行机械化剪毛可以提高羊毛的数量、品质、质量,进而提高牧业生产效率和经济效益。如何高质量、快进度地完成剪毛工作,对收获数量多、质量好的羊毛产品是一项重要的研究课题。本文通过参照国内外机械剪毛的各项实际操作,就机械剪毛技术水平现状、技术优势与效率、规范化操作要点与步骤等进行了梳理,就如何运用机械剪毛方式实现高效剪毛进行了总结和探讨,以期对细羊毛生产提供参考。     

乳杆菌电转化的研究进展

乳杆菌在食品、工业、微生物学等领域发挥着重要作用,作为益生菌,既可向体外生物反应器方向开发,又可作为潜在疫苗的抗原递送载体.由于乳杆菌属革兰阳性菌,细胞壁厚,重组质粒电转化效率低,甚至不能实现转化,影响了它作为基因工程受体菌的应用.笔者研究了近年来有关乳杆菌的电转化方案,总结了影响电转化效率的因素,如细胞壁预处理、电转缓冲液、电击参数、培养基、孵育时间以及菌体密度、质粒用量、热击条件等,并根据自己的试验结果提出优化方案,为乳杆菌在疫苗及生物反应器等领域的遗传开发研究提供较全面的借鉴.     

Human- Versus System-Level Factors and Their Effect on Electronic Work List Variation: Challenging Radiology’s Fundamental Attribution Error

PurposeThe aim of this study was to analyze sources of variation influencing the unread volume on an electronic abdominopelvic CT work list and to compare those results with blinded radiologist perception.MethodsThe requirement for institutional review board approval was waived for this HIPAA-compliant quality improvement effort. Data pertaining to an electronic abdominopelvic CT work list were analyzed retrospectively from July 1, 2013, to June 30, 2014, and modeled with respect to the unread case total at 6 pm (Monday through Friday, excluding holidays). Eighteen system-level factors outside individual control (eg, number of workers, workload) and 7 human-level factors within individual control (eg, individual productivity) were studied. Attending radiologist perception was assessed with a blinded anonymous survey (n = 12 of 15 surveys completed).ResultsThe mean daily unread total was 24 (range, 3–72). The upper control limit (48 CT studies [3 SDs above the mean]) was exceeded 10 times. Multivariate analysis revealed that the rate of unread CT studies was affected principally by system-level factors, including the number of experienced trainees on service (postgraduate year 5 residents [odds ratio, 0.83; 95% confidence interval, 0.74–0.92; P = .0008] and fellows [odds ratio, 0.84; 95% confidence interval, 0.74–0.95; P = .005]) and the daily workload (P = .02 to P < .0001). Individual faculty productivity had a weak effect (Spearman ρ = 0.13, P = .03; adequacy: 3% of variance explained). The majority (67%) of radiologists (8 of 12) completing the survey believed that variation in faculty effort was the most important influence on the daily unread total.ConclusionsSystem-level factors best predict the variation in unread CT examinations, but blinded faculty radiologists believe that it relates most strongly to variable individual effort.