Biomechanical tolerance of whole lumbar spines in straightened posture subjected to axial acceleration

Quantification of biomechanical tolerance is necessary for injury prediction and protection of vehicular occupants. This study experimentally quantified lumbar spine axial tolerance during accelerative environments simulating a variety of military and civilian scenarios. Intact human lumbar spines (T12‐L5) were dynamically loaded using a custom‐built drop tower. Twenty‐three specimens were tested at sub‐failure and failure levels consisting of peak axial forces between 2.6 and 7.9 kN and corresponding peak accelerations between 7 and 57 g. Military aircraft ejection and helicopter crashes fall within these high axial acceleration ranges. Testing was stopped following injury detection. Both peak force and acceleration were significant (p < 0.0001) injury predictors. Injury probability curves using parametric survival analysis were created for peak acceleration and peak force. Fifty‐percent probability of injury (95%CI) for force and acceleration were 4.5 (3.9–5.2 kN), and 16 (13–19 g). A majority of injuries affected the L1 spinal level. Peak axial forces and accelerations were greater for specimens that sustained multiple injuries or injuries at L2–L5 spinal levels. In general, force‐based tolerance was consistent with previous shorter‐segment lumbar spine testing (3–5 vertebrae), although studies incorporating isolated vertebral bodies reported higher tolerance attributable to a different injury mechanism involving structural failure of the cortical shell. This study identified novel outcomes with regard to injury patterns, wherein more violent exposures produced more injuries in the caudal lumbar spine. This caudal migration was likely attributable to increased injury tolerance at lower lumbar spinal levels and a faster inertial mass recruitment process for high rate load application. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 36:1747–1756, 2018.     

新型胸部CT参考体模的实验研究

作者报道新型胸部CT参考体模的实验研究和制作。本体模是按中国人体参数设计,高分子材料制成,对X线、γ线的吸收和散射与人体组织有相似特性,具有心、肺、骨骼、肌肉、脂肪和皮肤,是CT诊断、放射治疗、放射防护、教学和辐射剂量标准等研究的重要实验工具,可作为人的替身使用。CT研究结果显示,本新型胸部CT参考体模的解剖形态仿真,组织密度等效,同真人相似,由4或5个横断面组装成形,是一种多功能新型胸部CT参考体模,在放射科质量保证(qualityassurence,QA)和质量控制(quality control,QC)中有重要的理论和实用价值。作者对其临床应用和操作技术进行了讨论。     

不同种EP方案治疗老年人非小细胞肺癌的临床观察

目的 :探讨不同剂量及途径用药的EP方案治疗非小细胞肺癌的疗效和不良反应。方法 :1999年 1月～ 2 0 0 2年 1月将 14 3例非小细胞肺癌患者随机分为A(35例 )、B(36例 )、C(37例 )、D(35例 ) 4组 ,分别使用静脉小剂量滴注顺铂加口服足叶乙甙或静脉滴注足叶乙甙 ,以及静脉大剂量滴注顺铂加口服足叶乙甙或静脉滴注足叶乙甙四种EP方案治疗。结果 :4例EP方案的有效率分别为 4 0 .0 % (14 / 35 )、38.9% (14 / 36 )、4 0 .5 % (15 / 37)、4 2 .9% (15 /35 ) ;中位缓解期分别为 3.8月、4月、3.7月、3.4月。A组有白细胞下降、恶心、呕吐及脱发等不良反应最少 ,D组最多。结论 :静脉小剂量滴注顺铂口服足叶乙甙组成的EP方案简便、不良反应少 ,而且经济 ,适合老年人的非小细胞肺癌患者的姑息性治疗     

Reduction of patient radiation dose with a new organ based dose modulation technique for thoraco-abdominopelvic computed tomography (CT) (Liver dose right index)

Purpose

To evaluate the radiation dose reduction, image quality and diagnostic confidence with thoraco-abdominopelvic computed tomography (TACT) using a new organ based dose modulation system (liver dose right index [Liver DRI]), compared to TACT using a standard automatic exposure control adjusting mA according to attenuation.

检测血小板参数在血小板减少性疾病中的意义

目的探讨血常规检测中血小板（PLT）计数、血小板平均体积（MPV）及血小板分布宽度（PDW）在血小板减少性疾病中的意义。方法使用雅培CD-1800全自动血细胞分析仪进行检测。结果与健康对照组相比，在疾病组中，再生障碍性贫血PLT计数降低（P〈0．01），MPV降低（P〈0．01），PDW无变化；而急性白血病PLT计数降低（P〈0．01），MPV降低（P〈0．01）；PDW升高（P〈0.01）；特发性血小板减少性紫癜（ITP）组中，PLT计数减少（P〈0．01），MPV升高（P〈0．05），PDW升高（P〈0．01）。结论PLT、MPV、PDW在血小板减少性疾病的鉴别诊断中有较大的临床应用价值。     

New indicators in evaluation of hemolysis,elevated liver enzymes,and low platelet syndrome: A case-control study

BACKGROUNDIndices such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and red cell distribution width (RDW) are considered new markers of the systemic inflammatory response (SIR), and have been widely implemented for the diagnosis of patients with inflammatory diseases. These new indicators have also been widely investigated in preeclampsia (PE) but less analyzed in hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome.AIMTo compare SIR markers among HELLP patients, PE only patients, and healthy gravidae.METHODSThis retrospective case-control study enrolled 630 cases, including 210 patients with HELLP syndrome (HELLP group), 210 patients with only PE (PE group) and 210 healthy gravidae (control group). The three groups were matched by age, parity, status of assisted reproduction, and multiple pregnancies. Birthweight, gestational age at complete blood count collection, gestational age at delivery, mode of delivery, etc. were recorded. The main indices as NLR, PLR, MPV, PDW, and RDW among the groups were compared, as well as some secondary outcomes including neutrophil, platelets, and hemoglobin.RESULTSThe NLR (6.4 vs 4.3 vs 3.5), MPV (11.9 vs 11.2 vs 10.7), PDW (16.4 vs 13.3 vs 14.2), leukocyte (12.4 × 10⁹/L vs 9.7 × 10⁹/L vs 8.7 × 10⁹/L) and neutrophil count (9.9 × 10⁹/L vs 7.3 × 10⁹/L vs 6.1 × 10⁹/L) were highest in the HELLP group, lower in the PE group, and lowest in the control group. Both the overall comparisons between the three groups (all ^bP < 0.01) and pairwise comparisons between every two groups elicited statistically significant differences (all ^dP < 0.01, except control vs PE: ^cP < 0.05 in PDW). The average lymphocyte counts were 1.4 (1.1, 2.0) × 10⁹/L in the HELLP group, 1.6 (1.3, 2.0) × 10⁹/L in the PE group and 1.7 (1.4, 2.0) × 10⁹/L in the control group. The overall comparison of lymphocyte count within the three groups had statistically significant differences (P = 0.000). The pairwise comparisons between every two groups demonstrated that the HELLP group had a lower lymphocyte count than both the PE (P = 0.019) and control groups (P = 0.000), but the difference between the PE and control groups was not statistically significant (P = 0.432). The overall comparisons on platelet counts and the PLR among these three groups also showed statistically significant differences (both P = 0.000), from low to high being those in the HELLP group (43.4 × 10⁹/L, 64.0), control group (180.5 × 10⁹/L, 103.6) and PE group (181.5 × 10⁹/L, 112.8). Pairwise comparisons of neither index displayed statistically significant differences between the PE and control groups (both P > 0.05), while the differences in the two indices between the HELLP group and the two other groups were still statistically significant (all P = 0.000). RDW values were highest in the HELLP group (14.5% [13.6, 15.3]), lower in the control group (14.1% [13.5, 14.8]) and lowest in the PE group (13.9% [13.4, 14.9]). The difference between the PE and control group did not show statistical significance (P = 1.000), while RDW values in the HELLP group were higher than those in the other two groups (^cP < 0.05 vs control, ^dP < 0.01 vs PE).CONCLUSIONSIR markers such as NLR, RDW, MPV, and PDW were increased and PLR was decreased in HELLP. These SIR markers may become new indicators in the evaluation of HELLP syndrome.     

沙棘属药用植物亲缘学研究进展

沙棘作为一种既有经济效益又有社会效益的药食同源特色植物,素有“天然维生素宝库”“营养保健来源”等美称。早在公元8世纪已经发现沙棘有祛痰止咳,消食化滞,活血散瘀之效。研究表明沙棘属植物中含有黄酮类、萜类、挥发油类以及甾体类化合物,此外还含有大量的维生素、多糖、脂肪酸和人体必需的微量元素等生物活性物质,对心血管系统、血液系统、消化系统、免疫系统以及呼吸系统等方面的疾病有良好治疗作用。为了更深入的探讨沙棘属亲缘关系,现总结归纳了沙棘属植物的传统药用价值、化学成分及现代药理作用,并在此基础上寻找三者之间的相关性,为有效开发及合理利用本属资源提供依据。     

Comparative Study of Distribution of Active Sites According to Their Stereospecificity in Propylene Polymerization over the Traditional TiCl3 and Supported Titanium–Magnesium Catalysts with Different Composition

The preparative‐temperature rising elution fractionation method is used to obtain comparative data on contents of fractions with different microtacticities for polypropylene (PP) samples prepared using three catalytic systems: the traditional Ziegler–Natta (Z–N) catalyst δ‐TiCl₃ and two types of supported titanium–magnesium catalysts: the “donor‐free” TiCl₄/MgCl₂ catalyst and TiCl₄/MgCl₂·nDBP catalyst (DBP – dibutylphthalate used as an internal donor) at polymerization with the same cocatalyst (AlEt₃) in the absence and presence of an external donor (propyltrimetoxy silane). The separated individual PP fractions are also studied by gel permeation chromatography (molecular weight and molecular weight distribution) and differential scanning calorimetry. The results demonstrate general regularities and differences in the formation of active sites having different isospecificities for the traditional TiCl₃‐based Z–N catalyst and highly active supported titanium–magnesium catalysts.     

Pacinian Corpuscles in the Human Fetal Finger and Thumb: A Study Using 3D Reconstruction and Immunohistochemistry

The detailed distribution of Pacinian corpuscles was evaluated by viewing the transverse sections of all fingers and thumbs, including the interdigital areas, from eight hands of five fetuses of gestational age 28–33 weeks (crown‐rump length 230–290 mm). Among the 40 fingers and thumbs, serial sections were prepared for 3D reconstructions of nerve elements in the distal and middle phalangeal segments of three fifth fingers; in these three fingers, the distal segment contained 45–75 Pacinian corpuscles. These Pacinian corpuscles were 0.2–1.0 mm in length and 0.05–0.3 mm in thickness, oriented along the proximodistal axis and arranged along the palmar digital nerve branches. Other than beneath the digital skin, small corpuscles (<0.1 mm in thickness) were observed within the tendon sheath of the flexors in the middle or distal segment of five fetuses and in the nail beds of four fetuses. Clusters of 5–20 corpuscles formed bouquet‐ or tree‐like arrangements along neurovascular bundles in the fingers, thumbs and interdigital areas. Because the space beneath the skin was thick and loose in the interdigital area, trees in the interdigital area were up to 2 mm long. Regardless of site, the central core of each corpuscle was positive for S100 protein, while the core and parts of the capillaries in the corpuscle were weakly positive for nestin. Because corpuscles in the tendon sheath and nail bed, as well as bouquet‐ and tree‐like arrangements of corpuscles, have not been reported in adults, these morphologies are likely specific to fetuses. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:154–165, 2018. © 2017 Wiley Periodicals, Inc.     

自制脂质类超声造影剂肾增强效果的实验研究

目的探讨自制脂质类超声造影剂对正常兔肾的增强效果,以及不同显像方式、造影剂量对造影效果的影响与变化规律.方法 5只健康新西兰大白兔经耳缘静脉注射不同剂量的自制脂质类超声造影剂,剂量分别为0.01、0.03、0.05、0.08、0.10、0.13、0.15 ml/kg,每只兔各剂量均注射2次.用基波显像(FI)和实时造影匹配成像(CnTi)两种显像方式观察肾实质造影效果.结果 7种剂量水平均可使肾实质回声增强.CnTi随造影剂量增加肾实质增强强度提高,且增强时间延长.FI在上述各剂量水平肾实质峰值视频强度及增强时间均显著低于CnTi(P＜0.001).结论自制脂质类超声造影剂能够实现显著的肾实质增强效果,剂量-效应关系在CnTi造影中变化敏感,在FI造影中变化不敏感.