离子淌度质谱及其理论研究进展

离子淌度质谱是离子淌度分离与质谱联用的一种新型二维质谱分析技术，离子淌度分离原理是基于离子在飘移管中与缓冲气体碰撞时的碰撞截面不同，离子可按大小和形状进行分离。经过30多年的发展，离子淌度质谱已配有多种最新的离子源及质量分析器，理论研究也日渐成熟，并在蛋白质、多肽及复杂化合物异构体分析方面越发显示出独特的优势，正在发展成为一种新型的重要分析工具。     

用gap基因和MALDI-TOF MS技术对临床常见凝固酶阴性葡萄球菌快速分子鉴定

目的 研究旨在通过对比gap基因和基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF MS)蛋白质质谱鉴定,建立对临床常见凝固酶阴性葡萄球菌（coagulase negative staphylococcus,CNS）的快速分子学鉴定。方法 用gap基因对临床常见CNS进行扩增和测序,获得序列在GenBank中进行比对,构建进化树进行同源分析,同时与MALDI-TOF MS蛋白质质谱鉴定比较。结果 Gap基因相似率为39%～98%,有足够序列差异区分CNS。进化树同源分析显示,CNS分类具有较高的可信度（大于77%）;MALDI-TOF MS蛋白质质谱鉴定与gap基因鉴定符合率为100%。结论 MALDI-TOF MS蛋白质质谱鉴定可以用于CNS的快速、准确鉴定,比传统方法和分子方法具有优势。     

生物组织的基质辅助激光解吸电离质谱成像新进展

基质辅助激光解吸电离质谱成像技术分析组织切片已成为临床质谱学的一个新领域。该技术通过研究生物组织产生的“二维离子密度图像”，可以快速评估完整组织中蛋白质、药物及其代谢产物的空间分布。利用质谱成像技术研究阿尔茨海默病、神经胶质瘤、肺癌和前列腺癌等组织取得一定进展，本文对质谱成像原理、方法学及相关应用进行了综述。     

基于高通量测序数据的微生物检测算法研究进展

新一代高通量测序技术的发展,推动了多个相关研究领域的发展。国际上许多研究机构正在研究利用高通量测序数据进行微生物检测的算法,目前已有一些基于高通量测序数据的微生物检测算法流程设计成功并公开发布。该文通过调研利用高通量测序数据进行微生物检测的相关文献,研究已发布的基于高通量测序数据的微生物检测算法的功能和实现流程,分析几个有代表性算法的优点和不足。最后,对这些检测算法的设计思路进行总结和分类,提出基于高通量测序数据的微生物检测算法的改进设想。     

氨基酸组成分析直接鉴定SDSPAGE分离的研究简报蛋白质

蛋白质组学是后基因组时代研究的重要领域。蛋白质组研究的基本技术包括双向凝胶电泳分离技术、蛋白质鉴定技术、计算机图像数据处理与蛋白质组数据库构建等。氨基酸组成分析[1,2 ] 作为蛋白质组研究中的鉴定方法之一 ,对质谱鉴定、Ｎ端氨基酸序列鉴定等具有补充及验证作用。蛋白质是由 2 0种氨基酸通过肽键连接起来的生物大分子 ,测定蛋白质的氨基酸组成可获得蛋白质的基本信息。本研究以马心肌红蛋白和细胞色素Ｃ为样品 ,优化实验条件 ,以此建立一种高灵敏度、高准确度的鉴定双向凝胶电泳分离后的蛋白质点方法。该方法还可用于分析天然蛋…     

部分结构特殊多肽的纳升电喷雾串联质谱测序分析

目的：测定用Edman降解方法不能测序的结构特殊多肽的序列。方法：用纳升电喷雾四极杆－飞行时间串联质谱的de novo测序方法进行测序。结果：测定了亮丙瑞林、胸腺五肽及EPD等的多肽序列，这些多肽用Edman降解方法未能测定出序列。结论：串联质谱测序法是Edman降解测序法的最好补充，且具有灵敏，快速和样品用量少的优点。     

线粒体蛋白质组分离鉴定策略及数据诠释

线粒体功能和蛋白质组的改变可以导致各种退化性疾病如心肌病、衰老和癌症的发生，因此线粒体蛋白质组研究日显重要。线粒体纯度是困扰线粒体蛋白质组研究的一个基本但却关键的问题，也是线粒体蛋白质组数据诠稃及亚细胞定位的关键。对线粒体蛋白质一般采用质谱鉴定，鉴定前的分离纯化是高效鉴定的前提。线粒体蛋白质的分离有基于凝胶电泳和液相色谱的两种策略，它们可以以合理的方式组合达到最佳分离效果。对鉴定的线粒体蛋白质数据的合理诠释是解读线粒体表达谱和不同生理状态功能的最终目标。     

电离辐射诱导PC12细胞分化的蛋白质组学分析

目的探索辐射诱导PC12细胞分化的分子机理，筛选神经系统辐射损伤的分子靶标。方法16Gyγ射线照射PC12细胞，照射48h，提取正常与照射后细胞总蛋白，进行双向电泳分析，并对部分差异表达蛋白质进行质谱鉴定。结果电泳中共发现差异表达蛋白质位点876个。鉴定出表达水平增高的蛋白泛素羧端水解酶L1，表达水平降低的蛋白HP1α类似蛋白。结论应用蛋白质组技术鉴定出部分辐射后差异表达蛋白质，为辐射诱导PC12细胞分化的分子机理研究提供了线索。     

基于聚类分析和半监督学习的蛋白质质谱数据分类

目的针对高维冗余的SELDI蛋白质质谱数据,提出一种基于聚类分析和半监督学习的数据分类方法。方法算法首先运用t-test对蛋白质质谱数据进行初步降维;然后将处理后的数据用聚类分析算法进行进一步降维;最后运用半监督学习算法传递标签,充分提取有标记样本和无标记样本的信息,从而进行分类。结果在公共卵巢癌数据集OC-WCX2b和公共前列腺癌数据集PC-H4上获得了99.15%和96.75%分类准确率。在浙江省肿瘤医院临床乳腺癌数据集BC-WCX2a上获得了95.18%的分类准确率和100%的敏感性。结论基于聚类分析的半监督学习方法能够有效利用未标记的质谱样本信息,与经典的监督学习算法相比,其分类性能更理想、实用性更好。     

小鼠固醇载体蛋白2原核表达载体的构建与表达纯化

目的 构建小鼠固醇载体蛋白2(SCP-2)融合蛋白表达载体,并在原核细胞内表达及纯化获得具有活性的融合蛋白,为进一步研究SCP-2的生物学功能提供基础.方法 提取BALB/c小鼠肝脏组织总RNA,通过RT-PCR扩增得到鼠SCP-2编码序列,然后将该编码序列克隆到带有His标记的载体pET14b上,重组质粒经PCR、酶切及测序鉴定正确后转化大肠埃希菌BL21(DE3),用异丙基β-D硫代半乳糖(IPTG)诱导融合蛋白表达,用镍离子亲和层析的方法纯化融合蛋白并进行复性,然后切取分子量正确的条带用SDS-PAGE及质谱技术进行鉴定.结果 重组质粒经PCR、酶切和测序鉴定证明载体构建正确.融合蛋白表达纯化后获得了分子量约59kD的融合蛋白,符合预期大小,并经质谱分析证明该融合蛋白的表达正确.结论 成功构建了带His标签的SCP-2原核表达载体,并成功表达及纯化出该融合蛋白,为深入研究SCP-2的相关生物学功能提供了一个重要的工具.     

De novo aneurysm formation 6 and 22 months after initial presentation in two patients

Two cases of angiographically and surgically documented de novo intracranial aneurysm formation are reported. The first patient, a 32-year-old woman, developed two new aneurysms within a 6-month period, and the second patient, a 27-year-old woman, developed two new aneurysms within a 22-month period. In both patients, the new aneurysms were symptomatic, causing stroke and subarachnoid hemorrhage, respectively. The development of aneurysms de novo over such a short period of time has important implications for periodic imaging in patients considered to be at high risk for intracranial aneurysm formation.     

Development of de novo intracranial aneurysm in three months: case report and literature review

Summary: Formation of de novo intracranial aneurysms is rare. Their etiology is not known, but they are seen in patients with inherited collagen disorders, polycystic kidney disease, and familial history of aneurysms. Most de novo intracranial aneurysms are found 3-20 years after diagnosis of the initial aneurysm. We report the imaging findings in a 46-year-old man who developed a de novo intracranial aneurysm only 3 months after surgical clipping of another aneurysm.     

Development of "de novo" aneurysms following endovascular procedures

Two personal cases of "de novo" aneurysms of the anterior communicating artery (ACoA) occurring 9 and 4 years, respectively, after endovascular carotid occlusion are described. A review of the 30 reported cases (including our own two) of "de novo" aneurysms after occlusion of the major cerebral vessels has shown some features, including a rather long time interval after the endovascular procedure of up to 20-25 years (average 9.6 years), a preferential ACoA (36.3%) and internal carotid artery-posterior communicating artery (ICA-PCoA) (33.3%) location of the "de novo" aneurysms, and a 10% rate of multiple aneurysms. These data are compared with those of the group of reported spontaneous "de novo" aneurysms after SAH or previous aneurysm clipping. We agree that the frequency of "de novo" aneurysms after major-vessel occlusion (two among ten procedures in our series, or 20%) is higher than commonly reported (0 to 11%). For this reason, we suggest that patients who have been submitted to endovascular major-vessel occlusion be followed up for up to 20-25 years after the procedure, using non-invasive imaging studies such as MR angiography and high-resolution CT angiography. On the other hand, periodic digital angiography has a questionable risk-benefit ratio; it may be used when a "de novo" aneurysm is detected or suspected on non-invasive studies. The progressive enlargement of the ACoA after carotid occlusion, as described in our case 1, must be considered a radiological finding of risk for "de novo" aneurysm formation.     

Computer generated track and field scoring tables: II. Theoretical foundation and development of a model.

An investigation is made into the subject of scoring tables for track and field with emphasis on the application of computers to calculate and output the tables. The resulting scoring tables represent an attempt to describe the effective quality of performance for track and field events. This paper is published in three parts. The first portion reviewed the historical development of scoring tables. This part concerns the theoretical foundation and development of a mathematical model. A set of underlying principles and construction guidelines are established as a basis for all scoring tables. In order to satisfy the goals, a model which includes an exponential term is developed. The concept of a zero offset is introduced as a boundary value for the low-level performances. The final part concerns an evaluation of the model and an analysis of the point scores for different events.     

De novo basilar top aneurysm in an elderly patient treated with Guglielmi detachable coils

Ruptured de novo aneurysms, compared with the usual subarachnoid hemorrhage, commonly occur in younger patients and are extremely rare in elderly patients. We discuss their etiology and report the case of a ruptured de novo aneurysm in a 77-year-old woman.     

Assessment of calcium scoring performance in cardiac computed tomography

Electron beam tomography (EBT) has been used for cardiac diagnosis and the quantitative assessment of coronary calcium since the late 1980s. The introduction of mechanical multi-slice spiral CT (MSCT) scanners with shorter rotation times opened new possibilities of cardiac imaging with conventional CT scanners. The purpose of this work was to qualitatively and quantitatively evaluate the performance for EBT and MSCT for the task of coronary artery calcium imaging as a function of acquisition protocol, heart rate, spiral reconstruction algorithm (where applicable) and calcium scoring method. A cardiac CT semi-anthropomorphic phantom was designed and manufactured for the investigation of all relevant image quality parameters in cardiac CT. This phantom includes various test objects, some of which can be moved within the anthropomorphic phantom in a manner that mimics realistic heart motion. These tools were used to qualitatively and quantitatively demonstrate the accuracy of coronary calcium imaging using typical protocols for an electron beam (Evolution C-150XP, Imatron, South San Francisco, Calif.) and a 0.5-s four-slice spiral CT scanner (Sensation 4, Siemens, Erlangen, Germany). A special focus was put on the method of quantifying coronary calcium, and three scoring systems were evaluated (Agatston, volume, and mass scoring). Good reproducibility in coronary calcium scoring is always the result of a combination of high temporal and spatial resolution; consequently, thin-slice protocols in combination with retrospective gating on MSCT scanners yielded the best results. The Agatston score was found to be the least reproducible scoring method. The hydroxyapatite mass, being better reproducible and comparable on different scanners and being a physical quantitative measure, appears to be the method of choice for future clinical studies. The hydroxyapatite mass is highly correlated to the Agatston score. The introduced phantoms can be used to quantitatively assess the performance characteristics of, for example, different scanners, reconstruction algorithms, and quantification methods in cardiac CT. This is especially important for quantitative tasks, such as the determination of the amount of calcium in the coronary arteries, to achieve high and constant quality in this field. Electronic Publication     

Automatic detection of asymmetry in skin tumors.

Asymmetry, a critical feature in the diagnosis of malignant melanoma, is analyzed using a new algorithm to find a major axis of asymmetry and calculate the degree of asymmetry of the tumor outline. The algorithm provides a new objective definition of asymmetry. A dermatologist classified 86 tumors as symmetric or asymmetric. Borders of tumors were found either manually or automatically using a radial search method. With either method, asymmetry determination by the asymmetry algorithm agreed with the dermatologist's determination of asymmetry in about 93% of cases.     

Multi-region labeling and segmentation using a graph topology prior and atlas information in brain images

Medical image segmentation and anatomical structure labeling according to the types of the tissues are important for accurate diagnosis and therapy. In this paper, we propose a novel approach for multi-region labeling and segmentation, which is based on a topological graph prior and the topological information of an atlas, using a modified multi-level set energy minimization method in brain images. We consider a topological graph prior and atlas information to evolve the contour based on a topological relationship presented via a graph relation. This novel method is capable of segmenting adjacent objects with very close gray level in low resolution brain image that would be difficult to segment correctly using standard methods. The topological information of an atlas are transformed to the topological graph of a low resolution (noisy) brain image to obtain region labeling. We explain our algorithm and show the topological graph prior and label transformation techniques to explain how it gives precise multi-region segmentation and labeling. The proposed algorithm is capable of segmenting and labeling different regions in noisy or low resolution MRI brain images of different modalities. We compare our approaches with other state-of-the-art approaches for multi-region labeling and segmentation.