Implementation and validation of an implant-based coordinate system for RSA migration calculation

An in vitro radiostereometric analysis (RSA) phantom study of a total knee replacement was carried out to evaluate the effect of implementing two new modifications to the conventional RSA procedure: (i) adding a landmark of the tibial component as an implant marker and (ii) defining an implant-based coordinate system constructed from implant landmarks for the calculation of migration results. The motivation for these two modifications were (i) to improve the representation of the implant by the markers by including the stem tip marker which increases the marker distribution (ii) to recover clinical RSA study cases with insufficient numbers of markers visible in the implant polyethylene and (iii) to eliminate errors in migration calculations due to misalignment of the anatomical axes with the RSA global coordinate system. The translational and rotational phantom studies showed no loss of accuracy with the two new measurement methods. The RSA system employing these methods has a precision of better than 0.05 mm for translations and 0.03° for rotations, and an accuracy of 0.05 mm for translations and 0.15° for rotations. These results indicate that the new methods to improve the interpretability, relevance, and standardization of the results do not compromise precision and accuracy, and are suitable for application to clinical data.     

The effect of decreasing computed tomography dosage on radiostereometric analysis (RSA) accuracy at the glenohumeral joint

Standard, beaded radiostereometric analysis (RSA) and markerless RSA often use computed tomography (CT) scans to create three-dimensional (3D) bone models. However, ethical concerns exist due to risks associated with CT radiation exposure. Therefore, the aim of this study was to investigate the effect of decreasing CT dosage on RSA accuracy. Four cadaveric shoulder specimens were scanned using a normal-dose CT protocol and two low-dose protocols, where the dosage was decreased by 89% and 98%. 3D computer models of the humerus and scapula were created using each CT protocol. Bi-planar fluoroscopy was used to image five different static glenohumeral positions and two dynamic glenohumeral movements, of which a total of five static and four dynamic poses were selected for analysis. For standard RSA, negligible differences were found in bead (0.21±0.31mm) and bony landmark (2.31±1.90mm) locations when the CT dosage was decreased by 98% (p-values>0.167). For markerless RSA kinematic results, excellent agreement was found between the normal-dose and lowest-dose protocol, with all Spearman rank correlation coefficients greater than 0.95. Average root mean squared errors of 1.04±0.68mm and 2.42±0.81° were also found at this reduced dosage for static positions. In summary, CT dosage can be markedly reduced when performing shoulder RSA to minimize the risks of radiation exposure. Standard RSA accuracy was negligibly affected by the 98% CT dose reduction and for markerless RSA, the benefits of decreasing CT dosage to the subject outweigh the introduced errors.     

Validation of a behavioral recording automated system in the elevated plus-maze test

The elevated plus-maze test has been widely used for screening of anxiolytic drugs and for exploring neurobiological bases of anxiety. In this study, we validated a new automated system that enables to record exploratory behavior in the elevated plus-maze test. This system, called cyberplus, consisted of ten pairs of photoelectric cells strategically located in several parts of the apparatus, and seemed to be sensitive to the position of the animal's forepaws, so it would yield scores in anxiety measurements and locomotor activity similar to those obtained by following the traditional procedure, that is, by analyzing videotapes by experienced observers. In order to assess this hypothesis, we exposed rats to the elevated plus-maze test and compared the scores obtained by cyberplus with the values recorded by two independent observers, conducting a correlational study with both kinds of recording procedures. The results obtained suggest the utility of cyberplus as a behavioral recording automated system in the elevated plus-maze test, making data collection and data analysis easier in exploring pharmacological and neurobiological bases of anxiety.     

大型医院信息化网络平台的建设

现代化医院需要一个能够承载生命信息的数字化网络平台,面临大量的设备和众多的应用系统,网络架构的先进性、可扩展性、稳定性、可靠性和安全性是必须的。以瑞金医院信息网络平台建设为例,提出了大型现代综合性医院网络建设的难点和要点,认为网络系统建设可采用模块化、层次化的结构,提高网络的可扩展性和可管理性,减少网络广播的危害性,同时对关键节点采用冗余设备进行备份,对关键应用系统采用QoS、负载均衡技术优化网络总体性能,可加强网络运行的稳定性和安全性。     

数字X线摄影系统在新生儿检查中的应用评价

目的评价DR摄影系统在新生儿检查中的应用价值。方法利用CR系统和DR系统（使用剂量为前者的1／4）分别得到新生儿30幅图像。由6位医生来评价以上两者的影像系统对于导尿管末端的显影的清晰程度。结果二者的图像在诊断质量上没有统计学差异。结论DR有较好的分辨率和低噪声特性,高DQE有助于减少新生儿患者的接受剂量,图像传输速度快,使得临床诊断更为及时。     

用于海洋原位浮游生物探测的同轴数字全息显微技术研究

本文将数字全息与显微成像技术相结合,设计搭建了一套数字全息显微系统,用于对浮游生物进行光场获取。基于该系统获取的光场信息,通过在不同景深对图像进行再现,既可以获到单一浮游生物的清晰图像,也可以获得一定水体内浮游生物微粒在海水中的三维分布情况。通过实验测得系统分辨率可以达到7．8微米,景深可以达到10毫米,优于一般光学显微镜的技术指标。研究结果表明优势明显的数字全息显微系统是一种适合海洋原位探测的浮游生物研究的有效方法。基于数字同轴显微系统的水下仪器开发将是下一步工作的努力方向。     

Digital dermatoglyphic patterns in a sample of the Nigerian population

Eight hundred Nigerians (400 males and 400 females) were screened for the analysis of digital dermatoglyphic patterns. The frequency distribution of the patterns are 52.09%, 27.67%, 19.20% and 1.13% for ulnar loops, whorls, arches and radial loops respectively. Except for arches, the males have more of the patterns than females. The pattern intensity indices for males and females are 11.2 and 9.9 respectively. Bilateral symmetry is similar in both sexes and the percent distribution is as high as 81.5% and 84% on digit V in males and females respectively.     

数字化骨科理念辅助椎弓根置钉在寰枢椎不稳中的临床应用

目的:探讨3D打印辅助置钉技术用于寰枢椎不稳椎弓根置钉的安全性及准确性。方法:收集2013年1月到2015年1月西安交通大学第一附属医院收治的寰枢椎不稳病例,术前采用3D打印技术构建个体化3D打印模型,在模型上模拟置钉,获取最佳置钉点、置钉角度等个体化置钉数据,并于术中辅助椎弓根螺钉置入。通过CT扫描评价置钉准确性,测量术前、术后患者寰齿间隙判断寰枢椎复位情况,测量颈延角评价脊髓压迫改善情况,并采用日本骨科学会(JOA)评分判断患者脊髓功能改善情况。术后定期随访观察固定效果、稳定性、神经损伤等手术并发症的发生情况。结果:13例患者均采用3D打印辅助置钉技术进行内固定治疗,手术顺利,术中及术后无血管、神经损伤等并发症,复位及内固定效果满意。共置入椎弓根螺钉31枚,其中29枚完全在椎弓根内,置钉准确率为93.5%。寰枢椎较术前明显复位,术后寰齿间隙、颈延角和JOA评分较术前明显改善,差异具有统计学意义(P0.05)。结论:3D打印技术辅助上颈椎椎弓根置钉的准确性及安全性均较高。     

Assessing ecological risk through automated drainage extraction and watershed delineation

Decision makers are frequently involved in projects requiring ecological risk definition, which are inherent to biological conservation process. It is important to recognize these risks in order to invest wisely in the management and protection of biological resources. In this matter, Geographic Information System tools and remote sensing data have been used frequently as important components in planning and management of conservation units, Rabus et al. (2003), Valeriano et al. (2009) and Valeriano et al. (2010) stressed the advantages of using data that were gathered during the Shuttle Radar Topographic Mission (SRTM) for biological and geomorphologic purposes. For Brazil's national territory, the SRTM data were refined (Valeriano, 2008) and offered as free access on the TOPODATA Project website (http://www.dsr.inpe.br/topodata) where geomorphometric information (including elevation data) at a resolution of 30 m are provided. The aim of this paper is to demonstrate an example of how TOPODATA products have been applied in order to determine the ecological risk of the border of a Conservation Unit, located in the State of São Paulo—Brazil, in the Brazilian Atlantic Forest, using automated drainage network and watershed extraction. A comparison between SRTM, TOPODATA, and ASTER DEM was carried out, showing an advantage of TOPODATA drainage network product. The vectors generated using this data are more similar to the official drainage network vectors than the drainage network extracted using ASTER-DEM or SRTM. The network product generated using ASTER-DEM produced many commission errors and the one generated using SRTM produced a poor network, with generalized vectors, less detailed than the others. The results showed that using the TOPODATA Project‘s Digital Elevation Model (DEM) can provide important data for ecological analysis and significant additional information for decision making, regarding drainage networks and watershed features. The produced map for border ecological risk showed to fit perfectly to the field work analyses, produced in other works. Furthermore, the extracted watershed polygons might furnish important information unrevealing best conservation unit boundaries, which means more efficient management and best biological conservation results.     

数字化表达谱差异分析方法-DGE-P

目的：目前,关于数字化表达谱差异分析的方法及软件极少,且需懂得R语言等,操作繁琐,这给数字表达谱分析带来了不少困难,DGE-P软件针对数字化表达谱开发的差异分析软件。方法：DGE-P软件,利用倍数分析及数字化基因表达谱差异基因检测方法,对通过本软件标准化后的数据进行差异显著性分析。结果：DGE-P软件包含了丰度统计、数据标准化、求倍数分析和p-value值三个模块。可得出倍数分析与数字化基因表达谱差异基因检测方法（p-value）两个值。结论：DGE-P较以前的差异分析软件相比是一款针对数字化表达谱分析的软件,克服了其他软件在无重复实验数据时无法避免误差的缺陷。并且DGE-P较其他的软件相比使用方便,可在windows系统下运行,操作简单。     

改进底物添加体系制备氢化可的松

在蓝色梨头霉和新月弯孢霉协同转化制备氢化可的松(HC)过程中,常规的底物热溶液体系由17α羟基孕甾4-烯-3,20-二酮-21-醋酸酯(RSA)和乙醇组成,其中m(RSA)∶V(乙醇)=1∶25;改进后的底物溶液体系由Tween-80、丙三醇、RSA和磷酸盐缓冲溶液(PBS)组成,其中V(Tween-80)∶V(丙三醇)∶m(RSA)∶V(PBS)=1∶3∶1∶25。RSA质量浓度从2g/L起,累加到5g/L,RSA全部被转化,且产物氢化可的松(HC)产率与常规低浓度投料相当;在RSA质量浓度3g/L时添加底物,协同菌丝体能重复利用达3次,HC产率稳定在70%左右;经3批次实验室摇瓶放大制备实验,产物HC平均收率为52%,重现性较好,工艺操作稳定。Tween-80/丙三醇/RSA/PBS底物体系较常规RSA/乙醇构成的底物添加体系,可显著提高HC生产收率,有工业应用价值。     

Spotting and validation of a genome wide oligonucleotide chip with duplicate measurement of each gene

The quality of DNA microarray based gene expression data relies on the reproducibility of several steps in a microarray experiment. We have developed a spotted genome wide microarray chip with oligonucleotides printed in duplicate in order to minimise undesirable biases, thereby optimising detection of true differential expression. The validation study design consisted of an assessment of the microarray chip performance using the MessageAmp and FairPlay labelling kits. Intraclass correlation coefficient (ICC) was used to demonstrate that MessageAmp was significantly more reproducible than FairPlay. Further examinations with MessageAmp revealed the applicability of the system. The linear range of the chips was three orders of magnitude, the precision was high, as 95% of measurements deviated less than 1.24-fold from the expected value, and the coefficient of variation for relative expression was 13.6%. Relative quantitation was more reproducible than absolute quantitation and substantial reduction of variance was attained with duplicate spotting. An analysis of variance (ANOVA) demonstrated no significant day-to-day variation.     

Digital fluorescence imaging of fusion of influenza virus with erythrocytes

Fusion of influenza virus with human erythrocytes at pH 5.2 was followed by fluorescence microscopy using a cooled slow-scan CCD camera. The high sensitivity of the CCD permits repetitive digital imaging of the same cells with minimal photobleaching. The experimental conditions were such that only a small number of virus particles were adsorbed per cell. Quantitative analysis of the data indicated that for most cells only a single fusion event took place. This was, however, sufficient to cause haemolysis within 30 min at 20–22°C for about 60% of cells. There was a highly variable time lag between fusion and haemolysis. The lateral diffusion coefficient of virus particles on the cell surface when bound at pH 7.4 was < 2 × 10⁻¹³ cm²·s⁻¹. The technique should be of value for more detailed studies of the dynamics of viral and other membrane fusion events.     

Digital image analysis of Zostera marina leaf injury

Current methods for assessing leaf injury in Zostera marina (eelgrass) utilize subjective indexes for desiccation injury and wasting disease. Because of the subjective nature of these measures, they are inherently imprecise making them difficult to use in quantifying complex leaf injuries from multiple sources. We have developed a method using color digital photography of eelgrass leaves which are then manipulated using image processing programs and analyzed using geographic digital image analysis. The resulting false color images are then assigned by the user into uninjured and injured groupings which may then be reported as a percentage of leaf area affected. If images are rectified, leaf area (cm²) of injured and uninjured leaf segments may be determined. Although this method is time consuming and still requires some subjective judgments, it does allow for precise analysis of highly complex leaf injuries and has the potential to be a substantial improvement over existing leaf injury indexes.     

The ribosome's response to codon-anticodon mismatches

The ribosome is a molecular machine that synthesizes polypeptides from aminoacyl-tRNAs according to the sequence of the mRNA template. Codon reading by the anticodon of tRNA is controlled by a network of ribosome contacts that are specific for each position of the codon-anticodon duplex and involve A-minor RNA interactions. Rapid and accurate tRNA selection is accomplished by switching the conformation of the decoding site between accepting and rejecting mode, regardless of the thermodynamic stability of the respective codon-anticodon complexes or their interactions at the decoding site. The forward reactions are particularly sensitive to mismatches and determine the variations in the extent of misreading of near-cognate codons, both during initial selection and proofreading. This review emphasizes the progress made in understanding the mechanisms that determine recognition and selection of tRNA by the translational machinery.     

Enumeration of micro-organisms in processed soy products with an automated most probable number method compared with standard plate method

Aim: The automated TEMPO system (bioMerieux) is based on the most probable number (MPN) method for the enumeration of micro‐organisms in foods. In this study, we evaluated the performance of the TEMPO system as a diagnostic tool in comparison with the standard method in processed soy products. Methods and Results: A verification study was conducted using artificially contaminated soy product samples such as soy protein isolate, water‐soluble soy polysaccharides, soy milk and processed soy food. Five types of micro‐organisms were analysed using the automated MPN method (total aerobic bacteria, total coliforms, Enterobacteriaceae, yeast and mould and Staphylococcus aureus) vs the standard plate method. The results from each of the methods were highly correlated (r > 0·95). Naturally contaminated processed soy products on the market were also studied. There were no discrepancies observed between the respective methods. Conclusions: TEMPO methods were equivalent to the corresponding standard plate methods with very good rates of agreement. Significance and Impact of the Study: The automated MPN method is more practical and reliable for in‐house microbiological testing in processed soy products.     

Cold-microwave enhanced enzyme-linked immunosorbent assays—A path to high-throughput clinical diagnostics

The enzyme-linked immunosorbent assay (ELISA) constitutes an important clinical diagnostic approach. However, the prolonged incubation times involved lead to turnaround times of typically ?1 day, potentially delaying a definitive diagnosis or an adequate treatment plan for individual patients. Here cold-microwave technology (CMT) was employed to significantly reduce the times required for diagnostic ELISAs. The new approach was validated and compared to a conventional ELISA setup measuring canine calprotectin (cCP). Canine serum and fecal specimens were used for the analytical validation of cCP ELISA by conventional and CMT–ELISA. Cross-validation of both ELISA methods consisted of the determination of analytic sensitivity, linearity, accuracy, precision, and reproducibility. The long-term stability of antibody-coated ELISA plates was also evaluated up to 33 days. The ELISA approaches were comparable to each other. The observed-to-expected ratios for linearity and accuracy were 100.2 ± 11.8 and 98.1 ± 10.8% (mean ± standard deviation), respectively. Precision and reproducibility were ?17.2%. For samples run on precoated ELISA plates over 33 days %CVs were ?12.5%. While both ELISA approaches were analytically sensitive, linear, accurate, precise, and reproducible with measurements of cCP concentrations, CMT–ELISA offered a reduction in incubation times by 90–95%, facilitating a very fast turnaround time and suggesting CMT–ELISA for improved human and veterinary clinical diagnostics.     

Yeast-based automated high-throughput screens to identify anti-parasitic lead compounds

We have developed a robust, fully automated anti-parasitic drug-screening method that selects compounds specifically targeting parasite enzymes and not their host counterparts, thus allowing the early elimination of compounds with potential side effects. Our yeast system permits multiple parasite targets to be assayed in parallel owing to the strains’ expression of different fluorescent proteins. A strain expressing the human target is included in the multiplexed screen to exclude compounds that do not discriminate between host and parasite enzymes. This form of assay has the advantages of using known targets and not requiring the in vitro culture of parasites. We performed automated screens for inhibitors of parasite dihydrofolate reductases, N-myristoyltransferases and phosphoglycerate kinases, finding specific inhibitors of parasite targets. We found that our ‘hits’ have significant structural similarities to compounds with in vitro anti-parasitic activity, validating our screens and suggesting targets for hits identified in parasite-based assays. Finally, we demonstrate a 60 per cent success rate for our hit compounds in killing or severely inhibiting the growth of Trypanosoma brucei, the causative agent of African sleeping sickness.