生物荧光谱分离端元提取算法的实现与比较

选取和实现了PPI（Pure Pixel Index）和N-FINDR两种端元提取算法,在荧光染料发光成像的实验条件下对算法进行了对比发现：N-FINDR计算速度快,能准确计算出最优m个端元的优点,但需要对m数目预先准确设定,有可能会忽略本是端元的像素点;PPI算法计算速度较慢,会找出一些并不是端元的素点,但同时不会因为m的误差而误删除端元;本研究进一步发现,先通过一个较少循环的PPI算法来剔除大量的像素点,然后再通过N-FINDR算法对于剩余的像素点进行计算处理,可以更快速准确地分离出我们所需要的端元点。     

Intraoperative Radiotherapy

IORT is a promising tool for improving cancer treatment in patients with tumors that cannot be locally controlled by conventional surgery or radiotherapy. Results of clinical trials in progress should clarify its clinical merits and limitations in the treatment of locally advanced gastric, pancreatic, and retroperitoneal tumors. Principles and techniques are discussed.     

嗜肺军团菌荧光定量PCR检测

目的 建立特异、快速、敏感的TaqMan探针荧光定量PCR方法,用于检测嗜肺军团菌mip基因。方法 嗜肺军团菌及其他军团菌DNA模板来自中国疾病预防控制中心呼吸道室,嗜肺军团菌地方株及其他对照株由本中心菌种室供给。利用嗜肺军团菌mip基因保守序列设计引物和TaqMan探针,对其进行筛选,同时对荧光定量PCR反应条件和反应体系进行优化,并对嗜肺军团菌、非嗜肺军团菌及其他细菌进行检测,验证该方法的特异性、敏感性、重复性等。结果 该方法在检测多株嗜肺军团菌时,均出现阳性信号,而对非嗜肺军团菌和其他细菌则未有阳性扩增结果出现。检测灵敏度达10个拷贝/反应,从菌株核酸的提取至检测完成仅需2 h左右,可减少常规PCR操作的污染机会。结论 TaqMan荧光定量PCR方法可定量检测嗜肺军团菌,具有特异性高、快速、敏感等特点,适于外环境污染源状况的调查及应急事件的快速定量检测。     

Intraoperative cerebral ischaemia

The brain is highly vulnerable to damage from even a brief imbalance of oxygen delivery and demand. Most cerebral hypoxic damage is reversible, but infarction and permanent brain damage may result.     

荧光原位杂交技术在肾盂肿瘤诊断中的应用

目的 评价荧光原位杂交(FISH)技术在肾盂肿瘤诊断中的应用价值.方法 20例健康人通过FISH技术检测3、7、17号染色体及9号染色体p16位点的变异情况,建立阚值.15例影像学提示肾脏占位的血尿患者留取晨尿,分别进行尿脱落细胞学检查和FISH技术检测.以至少两种探针检测结果超过阈值或一种探针检测结果存在至少两种异常为诊断阳性.结果 15例血尿患者经手术及病理证实肾盂尿路上皮癌8例,肾透明细胞癌5例,肾嫌色细胞癌1例,黄色肉芽肿性肾盂肾炎1例.8例肾盂尿路上皮癌FISH技术检测均为阳性,3、7、17号染色体畸变阳性率均为100%(8/8),9号染色体p16位点畸变阳性率为75%(6/8).尿脱落细胞学检查仅1例阳性.7例非肾盂尿路上皮癌6例FISH技术检测阴性,而尿脱落细胞学检查则均为阴性.结论 FISH技术是一种无创快速诊断方法,在肾盂肿瘤诊断中优于尿脱落细胞学检查.     

术中超声和术中导航在颅内深部海绵状血管瘤切除术中的对比研究

目的对术中超声和术中导航两种定位方法在颅内深部海绵状血管瘤切除术中的应用进行比较,为临床手术提供更加准确的定位方法。方法37例颅内深部海绵状血管瘤患者,术中、术后分别行导航和超声检查,比较两种定位方法定位的准确性及对病灶切除范围判断的准确性。结果开颅去骨瓣后两种定位方法的准确率均为100%;术中进行定位时,术中导航定位准确率为70.3%,术中超声定位准确率为100%;术后判断病变切除范围时,术中导航准确率64.9%;术中超声准确率100%。结论在颅内深部海绵状血管瘤手术中术中超声定位较术中导航系统更加精确,有助于提高颅内深部海绵状血管瘤全切除率。     

Intraoperative neuromonitoring during endocrine surgery

Recurrent laryngeal nerve (RLN) injury is a known complication of thyroid surgery. Patients undergoing reoperations or extensive resections of malignancies carry an increased risk of nerve damage. The gold standard for preventing RLN injury is identification of the RLN. The development of a new technique has enabled intraoperative testing of RLN function. Intraoperative neuromonitoring has an excellent specificity and negative predictive value in which an unchanged positive signal is highly predictive of intact nerve function. This technique facilitates RLN identification in altered anatomy as is found at reoperation and can prevent bilateral vocal cord palsy. Additionally the prognosis of patients with postoperative voice symptoms can be supported by the objective intraoperative measurements.     

Intraoperative MRI in brain surgery

Neuronavigation is a frequently used method in the planning of intracranial neurosurgical procedures. During surgery however, due to anatomical changes such as loss of cerebrospinal fluid, tumour resection and oedema, preoperative data become inaccurate. Updated data acquisition during the procedure using intraoperative MRI (iMRI) overcomes this problem, as it enables maximum tumour resection or accurate tumour biopsy, whilst minimizing the risk of damaging healthy brain tissue. The choice between low field and high field strength systems depends on the desired image quality and integration into the regular workflow. In spite of its high costs, iMRI surgery seems to be cost-effective, due to reduced length of hospital stay, reduced repeat resection, and reduced hospital charges. In the future, intraoperative imaging combined with virtual planning stations, is expected to play an important role in implementing robotization into neurosurgery.     

原子荧光光谱法测定尿汞的最佳条件分析

将尿液湿法消解后,其中的汞在酸性条件下被硼氢化钾还原,经原子荧光光谱仪测定尿汞。结果显示,最佳条件为灯电流及负高压为20 mA、200 V,载气、屏蔽气分别400 ml/min和800 ml/min,原子化器高度为10 mm,读数时间为12 s,延迟1 s,载流为5%盐酸,还原剂为0.1%的硼氢化钾。该方法在0～10μg/L范围内线性相关系数在0.999 0～0.999 8,检出限可达0.002μg/L,精密度1.8%,具有应用及推广价值。     

Immediate screening of lead exposure in the workplace using portable X-ray fluorescence

The use of a portable X-ray fluorescence spectrometer (PXRF) equipped with a miniaturised X-ray tube producing a small 8 mm diameter X-ray beam required the validation of two new sampling protocols for the immediate screening of occupational lead exposure.

First, lead in dust and fumes, collected by Institute of Occupational Medicine (IOM) inhalable samplers on 25 mm diameter membrane filters, is quantified using PXRF. To account for irregular dust deposition, the filters are rotated manually by quarter turns. Multiple PXRF readings are collected from the central region and from two locations in the outer region. The inner region is distinguishable from the outer region, but the two outer region locations are indistinguishable.

High correlations (R² > 0.99) are found between the PXRF results and historical results obtained using a reference method based on a laboratory wavelength-dispersive sequential XRF instrument (WDXRF) for lead loadings between 1–161 μg. The PXRF results from the outer regions of the filters show a bias of ?13% with respect to the WDXRF. Once this bias is allowed for, 95% of all PXRF results lie within ?28% and +38% of the WDXRF results. Neither instrument accounts for potential dust accumulation on the walls of the IOM sampler. Therefore, methods based on their use can only be considered semi-quantitative.

Second, a protocol combining direct PXRF measurements on workplace surfaces with surface wipes is designed for immediate on-site quantification of removable surface lead residues. The quantification of such residues by this method is compared with subsequent off-site wet chemistry analysis of the surface wipes. The two methods show a good correlation (R² ～ 0.88). The ratio of the amount of removable residues determined by PXRF and wipe sampling is close to one with range 0.26–3.94.

It is demonstrated that PXRF can be used as an effective tool for the immediate screening of occupational lead exposure. Although this article focused on lead, PXRF can identify simultaneously a number of other metals.     

Cadmium in kidneys in Swedes measured in vivo using X-ray fluorescence analysis

An X-ray fluorescence (XRF) technique using plane polarized X-rays for excitation was used for in vivo measurements of cadmium in the kidney cortex among non-occupationally exposed members of the general population in southern Sweden. The measured concentrations of cadmium in the kidney cortex of smokers (median 28 g/g, n = 10) were significantly higher (P = 0.0036) as compared to those in non-smokers (median 8 g/g, n = 10), and so were the cadmium concentrations in blood and urine. The results show that smoking considerably increases the cadmium concentration in the kidney cortex and that smoking is a major source of cadmium exposure in the general population of Sweden. Except in the presence of very deeply situated kidneys, where the minimum detectable concentration is high, non-invasive in vivo XRF analysis of kidney cadmium should be a useful tool for evaluating the effects of long-term low-level exposure to cadmium and the risk of kidney damage.     

Possibilities of low-power X-ray fluorescence spectrometry methods for rapid multielemental analysis and imaging of vegetal foodstuffs

In the present contribution the possibilities and drawbacks of two analytical strategies based on the use of low power X-ray fluorescence systems (EDXRF and μ-XRF) have been explored for rapid multielemental analysis and chemical imaging of different edible vegetal species. The proposed methodologies allow analysis of vegetation material without complex sample treatments providing relevant advantages in terms of simplicity and costs compared to classical destructive methods. As study cases, we have focused on the analysis of different parts of several vegetal species (Daucus carota, Spinacia oleracea, Cynara scolymus, Raphanus staivus, Coriandrum sativum) collected in agricultural soils irrigated with municipal treated wastewater samples. EDXRF and μ-EDXRF data revealed that content of some major elements such as P and S increased if crops are irrigated with municipal treated wastewater although the distribution of these elements is not depending of the type of water used for irrigation purposes. On the contrary, trace element content is not significantly higher in comparison to vegetables irrigated with fresh water, except for bromine. The findings of this contribution can contribute to expand the knowledge about the impact of the use of reclaimed wastewaters for irrigation on vegetal composition but the use of the aforementioned XRF techniques could be also extended to other food safety and nutritional studies.