载人航天器环控生保系统热网络的轻量化分析

目的 减轻载人航天器中环控生保系统的重量,方法采用网络分析原理,出环控生保系统中气、液流体回路所构成的流动和热网络,建立此网络中流动、传热及重复计算的物理模型和数学模型。从热平衡、热热及其系统重量关系式出发,计算出网络的结点热力学参数及网络系统重量,并对系统重量的一些影响因素进行了分析。结果 流动和热网络系统中存在最侍者这径,使系统重量最小。并且此最佳管径与流量关系密切;适当地提高通风温度可以降低     

对机械通气中呼气峰流量法计算呼气阻力公式的分析

目的通过分析机械通气呼气峰流量时刻对应的回路压、容积,及增加回路不同部位阻力后气道阻力的变化特点,来分析机械通气时用呼气峰流量法“Re=(PPlat-PEEP)/Ve”所计算的呼气阻力的准确性与影响因素。方法将夹板模拟肺通过呼吸回路与呼吸机相连。①观察分析呼气峰流量时刻气道两端的压力：选择容量控制通气模式,留置平台时间,进行通气;锁屏后,观察呼气峰流量时刻对应的回路压力与所设置的呼气末正压（PEEP）间的关系;观察此时的容积与吸气平台期容积之间的关系,以此来推测此时的肺泡内压与平台压（Pplat）间的关系。②验证呼吸机回路呼气支阻力对所计算的气道呼气阻力的影响：分别用夹子依次增加回路吸气支阻力、呼气支阻力、Y型管后延长管（相当于气道）阻力,观察其对所计算的吸气阻力（Ri）与呼气阻力（Re）的影响。③观察管路内气流释放对呼气峰流量的干扰：在正常回路状态,在一次正常通气的平台期,完全夹闭Y型管后延长管,待进入呼气时刻,管路气流释放后,再松开夹闭,让模拟肺内气流排出;观察由单纯模拟肺内气流排出形成的呼气峰流量与未干预状态下的呼气峰流量间的关系。结果①呼气峰流量时刻对应的气道两端压力：压力-时间曲线显示,此时外口压力（回路压力）明显高于PEEP;容积-时间曲线显示,呼气峰流量点的容积要略小于平台期的容积,意味着,此时内口压力（肺泡内压）会略低于Pplat;即,气道内外口实际压力差要明显小于“PPlat-PEEP”。②气道阻力与回路阻力关系：增加回路吸气支阻力时,Ri/Re均无明显变化;增加呼气支阻力时,Ri无明显变化,Re明显增加;增加延长管阻力时,Ri/Re均同时明显增加。即,回路呼气支的阻力明显影响所计算的呼气气道阻力。③管路对呼气峰流量的影响：流量-时间曲线显示,管路的回缩可形成明显的瞬时呼气气流,后续来源于模拟肺的呼气峰流量会略低于未干预状态下的呼气峰流量,即管路回缩释放的气流对实际的呼气峰流量存在影响。结论因呼气峰流量时刻气道两端的压力差小于“平台压-PEEP”,且呼气峰流量包含管路回缩产生的流量,导致呼气峰流量法呼气阻力计算公式的计算结果存在一定的不准确性,其结果包含回路呼气支的阻力;当回路支阻力明显增高时,会严重干扰计算结果,临床上需有清晰的认识。     

热电集成薄膜蒸发废水处理系统的轻量化分析

目的 在满足净水产量和卫生要求的条件下，使载人空间飞行器环控生保系统的热电集成薄膜蒸发废水处理系统的设计质量达到系统水平上的轻量化。方法 根据热电集成薄膜蒸发废水处理系统工作过程的特点，建立其主要部件的流动、传热和质量构成的物理数学模型，用数值方法对系统质量与结构参数、操作参数的关系进行研究。结果 系统的质量不仅与废水处理系统本身的结构参数、操作参数有关，而且与电源系统和热控系统的工作特性关系密切。相关质量在系统质量构成中占有较大比例。结论 废水处理系统的热电制冷元件的数目、废水的循环流量存在最佳值，使系统的设计质量最小。而较高的系统冷凝压力，有利于系统质量的降低。     

载人航天器通风除湿系统运行参数的优化分析

目的：研究载人航天器通风除湿系统运行参数及一些组件的设计与优化方法，方法：建立了载人航天器通风除湿系统的数学物理模型，通过设计合适的系统运行参数及时有效地除去舱内产生的热量、水分、防止结露，满足人体的舒适性要求，并且采用计算的方法，分析了各种运行参数及组件对系统当量质量的影响。结果：载人航天器进舱气流温度、相对湿度及通风率、稻谷散湿量都影响舱内气体的露点温度及舒适性。舱内空气参数的有两种方式：以控制温度为主要目标的设计方法，回路中不需要使用余热回收换热器，结构简单，但有时不能满足除湿要求，优先满足湿度控制目标的方法，能够稳定控制舱内露点的温度、有利于防止结露，但系统结构较为复杂，结论：在保证系统性能的前提下，采用优化设计措施可以减轻空气处理系统的质量及耗电量，实现系统的轻量化。     

适用于空间细胞培养系统的泵头分体式直流电机驱动微泵

目的为了搭建适用于我国航天医学细胞生物学研究的小型化、集成化、自动化细胞培养系统,提出了一种性能可靠、操作维护简单、成本低廉且自带阀控功能的泵头分体式直流电机驱动型蠕动微泵。方法测试了基于不同额定电压直流电机和减速比构建的微泵工作性能;并以该微泵为核心部件建立了自动细胞培养回路,开展了空间实验常用细胞系MG63和血管内皮细胞的中长周期培养试验。结果零背压下微泵流量与驱动电压呈良好的线性关系,以额定电压8 V(16 V)电机构建的微泵,电压由6 V增至10 V(8 V增至12 V)时,流量由0.29 m L/min增至0.67 m L/min(2.63 m L/min增至4.95 m L/min);持续15 d的测量表明微泵工作稳定性很好。MG63和血管内皮细胞均可在以该微泵为核心的自动细胞培养回路中正常生长达15 d。结论该泵头分体式直流电机驱动微泵工作污染风险低,流量易调,可满足我国空间自动化细胞培养系统搭建的需求。     

环控生保集成演示验证系统总体设计及其试验验证

目的：研制环控生保集成演示验证系统，为未来中长期环控生保系统技术的研究创造一个先进的地面研究试验环境。方法：将固态胺二氧化碳收集浓缩、Sabatier二氧化碳还原、全氟磺酸热电综合膜蒸发尿处理和固态聚合物水电解制氧等再生式生保技术、集中通风温湿度控制技术、测量控制等非再生式技术集成在一密封绝热环境中，并通过试验考核。结果：系统及再生式各分系统主要技术指标满足要求，系统总体及各分系统的整合是成功的，基本上达到了系统整合部分闭环。结论：系统方案设计合理，系统的主要性能技术指标满足要求。系统总体及所属各个分系统之间匹配与协调性良好，系统运转正常，测试数据正确。     

前门控在256层螺旋CT冠脉成像中应用的探讨

目的通过分析冠脉CTA图像质量及辐射量探讨前门控对冠心病的临床应用价值。方法选取行冠脉CTA检查患者500例,心率≤70次／min者124例;心率〉70次／min者376例,前者随机分为前后门控两组,后者均为后门控扫描。结果心率≤70次／min者,前后门控两组图像质量评分分别为4．14±0．87和4．15±0．83,差异无统计学意义（P〉O．05）;有效辐射量分别为（1．89±0．57）mSv和（15．01±4．13）mSv,差异有统计学意义（P〈0．05）。心率〉70次／min者：71～85次／min者优质图像所在R—R间期百分比具有不确定性;心率〉85次／rain者100％在40％～50％R—R间期。结论心率≤70次／min时,前后门控冠脉成像图像质量具有一致性,前门控明显降低了辐射量;心率〉70次／min者也可以应用前门控技术扫描。     

便携式给氧复苏呼吸器的设计

目的：设计一款具有复苏和吸氧双重功能的便携式呼吸器。方法采用正压式、气动气控的设计方案,对关键部件进行了理论计算,利用三维设计软件 Solidedge 进行了虚拟样机的构建、结构的校核,最后对样机进行了加工装配和测试。结果经过实验测试,所研制的呼吸器在3～5．5 bar 气源压力下能实现急救复苏和辅助吸氧功能,给氧流量10～12 L／min,达到预期技术指标。结论便携式给氧复苏呼吸器具有体积小、重量轻、操作简单、便于携带、无需电源等特点,具有广阔的应用前景。     

载人航天器密封舱压控规律解析解及其实验验证

目的：导向载人航天器密闭舱总压和氧分压变化规律的解析解，环控生保总体设计师可以此作为飞行或地面试验时压控参数预测的依据。方法：将飞行时段分段化，对系统规定的压力控制带下不同的供气工况分别进行理论推导，解微分方程组，得出不同供气工况座舱总压和氧分压的解析解，结果：试验结果和理论计算结果吻合较好，结论：本文导出的解析解正确，满足工程精度要求。     

评价“胸痛三联排除”的CT冠状动脉血管成像扫描方法在疑有低到中度急性冠状动脉综合征危险的急诊病人64层CT检查中的应用

目的比较一组接受前瞻性心电门控64层CT冠状动脉成像病人及另一组接受回顾性心电门控64层CT冠状动脉病人的成像质量及病人放射剂量。方法本研究依从HIPAA法案并得到了机构审查委员会的批准。由于设计是回顾性研究故不需要知情同意。2位独立阅片者分别对100例病人心脏CT成像（每组各50例）的冠状动脉进行分段影像质量评分和综合评分。计算观察者间偏差。记录对应实际扫描Z轴长度的病人放射剂量，以Z轴长度为12cm的典型心脏计算标准化剂量。结果2组病例的临床特征及CT参数匹配良好。     

胎儿脐带绕颈的彩色多普勒血流检测与临床分析

目的探讨应用彩色多普勒超声检测脐带绕颈胎儿脐动脉血流参数改变的临床意义,帮助临床选择正确的分娩方式,降低围产儿死亡率。方法以行产前（1周内）检查及分娩的足月单胎头位孕妇作为观测对象。检出脐带绕颈246例,分为脐带绕颈1周组、2周组和3周组,以60例无脐带绕颈者作为对照组,比较各组脐动脉阻力指数（RI）及收缩期最大血流速度与舒张末期最大血流速度比值（S／D）。另与843例无脐带绕颈者比较分娩方式及结果之间的差异。结果脐带绕颈1周组RI、S／D与对照组比较无显著性差异（P〉0．05）,脐带绕颈2、3周组RI、S／D明显高于对照组（P〈0．01）。脐带绕颈组胎儿宫内窘迫率、胎儿剖宫产率及羊水过少的发生率明显高于无脐带绕颈组（P〈0．01）。结论脐动脉血流RI、S／D值是判断脐带绕颈胎儿宫内缺氧的敏感可靠指标,对临床选择合理的分娩方式。减少围产儿并发症具有指导意义。     

Congenital internal hernia as a cause of small bowel obstruction: CT findings in 11 adult patients

The aim of this study is to report the CT findings in patients proved to have congenital internal hernia (CIH) as a cause of small bowel obstruction (SBO). The CT scans of 11 patients (9 men and 2 women, with ages ranging from 20 years to 95 years (mean 60.7 years), presenting with clinical symptoms and signs of SBO without previous abdominal surgery or trauma, were retrospectively reviewed. In all patients features of SBO were seen. In addition, in nine of them a saclike mass, containing dilated small bowel loops with mesenteric vessels converging toward its orifice was demonstrated and a pre-operative diagnosis of an incarcerated internal hernia was suggested. In the other two, a closed loop obstruction was seen without an identifiable cause. Mural thickening of the entrapped loops within the hernial sac was seen in five patients, with hypoperfusion in four of them, blurring of the mesenteric vessels with localized mesenteric fluid was demonstrated in seven and free peritoneal fluid in 10. All patients were operated on following the CT and an incarcerated CIH was confirmed. Gangrenous bowel was present at exploration in seven cases. One patient died. In conclusion, in patients with intact abdomen and SBO, CT may be the first imaging modality to discover a clinically unsuspected CIH, which requires prompt surgical intervention. Radiologists should be aware of the CT features suggestive of a SBO caused by CIH, i.e. a saclike mass of dilated small bowel loops, as a correct diagnosis will influence patient management and prognosis.     

Preclinical testing of a new clot-retrieving wire device using polyvinyl alcohol hydrogel vascular models

Introduction Cerebral embolism is the principal cause of cerebral infarction. Recently, mechanical embolectomy has been proposed as an effective method. We performed a preclinical evaluation of a new mechanical clot-retrieving wire. Methods This clot-retrieving wire consisted of three nitinol loops at the tip of a microguidewire. These three loops could be collapsed into a 0.018-inch wire compatible microcatheter. Each loop was 8 mm long and 3.5 mm wide. For simulation, polyvinyl alcohol (PVA) vascular anatomical models of the human carotid (eight models) and vertebrobasilar (three models) circulation were constructed. A pulsatile flow circulation system was used. Embolic clots were produced using pig blood plasma. The microcatheter and the microguidewire were advanced beyond the clot. The wire was then exchanged for the retrieving wire. The microcatheter was then pulled slightly back to open the loops. The clot was then caught by withdrawal of the system. Once caught, the clot was retrieved to the guiding catheter tip. We investigated the following points: ease of device deployment, clot capture ability, clot removal against blood flow and removal of the clot out of the introducer system. Results A total of 104 procedures were performed in 11 PVA models and evaluated. The drop rate was 19%. We succeeded in partial and total recanalization in 51.0% of the procedures (53/104) within 30 minutes. Conclusion This new clot-retrieving wire could be useful for mechanical clot extraction in stroke.     

Obstructed ectopic kidney mimicking Chilaiditi syndrome on F-18 FDG imaging

Fluorine-18 fluorodeoxyglucose positron emission tomography was obtained in a patient with a duodenal mass. Conventional imaging revealed multiple dilated intestinal loops. Initial impression of positron emission tomographic images was interposition of a loop of bowel between the liver and diaphragm (Chilaiditi syndrome) in an unusual location, with absent right kidney activity. Computed tomography and magnetic resonance imaging of the abdomen showed an obstructed ectopic kidney in this position with a markedly dilated collecting system. There is absence of fluorodeoxyglucose in the markedly dilated renal collecting system resulting from acute obstruction, giving the false appearance of gas-filled bowel loops with an unusual location of the interposition.     

粘连性腹内疝及其合并肠缺血坏死的MSCT诊断

目的 探讨粘连性腹内疝及合并绞窄性肠坏死的MSCT特征.方法 回顾性分析21例经手术证实的粘连性腹内疝的CT资料,CT原始数据经多平面重建(MPR)及CT血管造影(CTA),以显示疝环、疝入肠系膜、疝内肠管的特征.结果 19例粘连性腹内疝均显示疝环,小肠扩张积液、聚集并移位,其中17例显示疝环处肠管狭窄与扩张肠管移行;17例显示疝入肠系膜水肿、增厚,肠系膜血管纠集、充血,其中11例显示疝环处肠管及其系膜扭转;15例显示腹水.根据疝入肠管影像表现将粘连性腹内疝分型:Ⅰ型为肠管扩张伴肠壁增厚(7例);Ⅱ型为肠管扩张不伴肠壁增厚(9例);Ⅲ型为肠管不扩张但肠壁增厚(5例).3型腹内疝肠管壁平扫CT值、动脉及门脉期肠壁强化值差异有统计学意义(P<0.05),Ⅰ和Ⅲ型小于Ⅱ型,Ⅰ、Ⅲ型之间的差异无统计学意义(P>0.05).8例粘连性腹内疝合并绞窄性肠坏死(5例为Ⅰ型,3例为Ⅲ型),CT显示肠扭转伴疝入小肠壁显著水肿增厚,肠壁模糊呈持续性低强化,其中4例显示肠系膜上静脉血栓栓塞,3例显示肠系膜上动脉主干或分支闭塞,8例均显示大量腹水.结论 粘连带形成的疝环,狭窄与扩张肠管移行以及小肠扩张、聚集并移位提示粘连性腹内疝的存在;疝入肠系膜水肿,血管纠集,充血,肠系膜血管闭塞,肠管壁显著水肿增厚并持续低强化,则是绞窄性肠坏死的影像特征.     

Assessing the Impact of Referral on Multidisciplinary Tumor Board Outcomes in Patients With Hepatocellular Carcinoma

Background and AimsHepatocellular carcinoma (HCC) is a complex and unique cancer. At many tertiary care institutions, optimal treatment is planned at a multidisciplinary liver tumor board (MDLTB). This study examined the impact of referral on MDLTB outcomes for patients with HCC.MethodsChart review was performed of incident HCC cases presented over 3 years at an American College of Surgeons accredited MDLTB. Internal cases were defined as patients whose care originated within the tertiary care institution of the MDLTB; external cases were defined as patients who received initial care from outside institutions and referred to the tertiary care MDLTB for consultation. Internal and external cases were compared for differences in HCC diagnosis, treatment, and survival.ResultsThere were 120 internal cases and 163 external cases. Compared with internal cases, external cases took significantly more time to be diagnosed with HCC (4.5 versus 37.5 days, P < .001) and to be discussed at MDLTB (19 versus 53 days, P < .001). Internal cases were more often diagnosed by imaging studies (77.5%), and external cases were more often diagnosed by biopsy (43%) or by consensus of experts at MDLTB (26%).ConclusionPatients with HCC, whose care originated within the tertiary care institution of the MDLTB, were less likely to require biopsy and had shorter time from initial suspicion to diagnosis of HCC. The data suggest that referral of external HCC cases to a tertiary center MDLTB at initial suspicion may limit unnecessary diagnostic procedures, possibly resulting in decreased health care costs and reduced uncertainty for patients.     

彩色多普勒超声对颈动脉体瘤的诊断价值

 目的 探讨彩色多普勒超声在颈动脉体瘤诊断中的应用价值.方法 回顾性分析7例颈动脉体瘤患者的二维及彩色多普勒超声表现.所有病例均经手术病理证实.结果 颈动脉体瘤二维超声表现为颈动脉分叉处见实质性低回声肿块,边界清晰,边缘规则或呈分叶状.肿瘤较小时,多位于颈总动脉分叉处,使颈内、外动脉间距增大,形状多较规则;肿瘤较大时,常围绕血管生长.彩色多普勒超声均可见肿瘤内有较丰富的彩色血流信号,以动脉血流为主;CDFI还能清晰显示肿瘤与颈动脉的关系.结论 二维及彩色多普勒超声对诊断颈动脉体瘤具有无创、安全、特异性、准确性高的特点,有利于同颈部其他性质包块的鉴别诊断,是目前颈动脉体瘤诊断的首选方法.     

航船信息系统与航海环境医学

航海环境医学涉及人、机器、环境间的关系问题，可从信息系统的角度进行分析。航行中的船舶应看作是由多层次、多种类的子系统组成的反馈网络，这一网络之存在及其正常运行依赖于不停地进行内外信息交流。大多数导致航行失败的事故都与网络内的信息流动受阻或中断有关。如何运用信息系统原理，采取必要措施，维持人体系统（尤其是脑）在航海特殊环境条件下的正常信息运动，是现代航海环境医学须要重视的研究内容。     

封闭型空间细胞培养板研制与验证

目的为适用于空间特殊实验环境,并在细胞培养实验中更高效地使用试剂、提高细胞培养用品的污染防护能力,提出了一种内部流动路径可控、具备防渗漏、防污染能力的全透明和全封闭细胞培养板。方法基于有限元仿真对培养板核心结构—流路控制挡板进行了优化,以优化后的培养板为核心部件搭建细胞培养回路,并开展了中长周期细胞培养试验。结果最优化的三坝-纵向排列细胞培养板,可有效控制其内部流体的流动路径,进出口流速1 m L/min时流体剪切力仅4.8×10~(-5)Pa,流动死区几乎为0,以该培养板为核心构建的细胞培养回路中培养的细胞可正常生长15 d。结论该细胞培养板,可使腔内新旧细胞培养试剂更换及残留气体排出更彻底,防渗漏防污染能力大大提升,试剂使用率提高,能满足空间实验常用典型细胞系的中长期培养需求,适合于我国目前及将来的空间医学生物学实验应用场合。