Clinical infrared microscopic imaging: An overview

New developments in Mid-infrared microscopic imaging instrumentation and data analysis have turned this method into a conventional technique. This imaging method offers a global analysis of samples, with a resolution close to the cellular level enabling the acquisition of local molecular expression profiles. It is possible to get chemo-morphological information about the tissue status, which represents an essential benefit for future analytical interpretation of pathological changes of tissue. In this review, we give an overview of Mid-infrared microscopic imaging and its applications in clinical research.     

自身化学离子化/傅里叶变换质谱法研究复杂有机化合物的分子量

自身化学离子化/傅里叶变换质谱(SCI/FTMS)技术研究能挥发的复杂有机化合物,可同时获取准分子和特征碎片的信息。本文研究并测定了一系列这类化合物。     

自身化学离子化/傅里叶变换质谱法研究复杂有机化合物的分子量

自身化学离子化/傅里叶变换质谱(SCI/FTMS)技术研究能挥发的复杂有机化合物,可同时获取准分子和特征碎片的信息。本文研究并测定了一系列这类化合物。     

Influence of external energy sources on the dynamic setting process of glass-ionomer cements

Objective

To evaluate the influence of external energy sources on the dynamic setting process of glass-ionomer restorative materials.

基于小波变换结合其他预处理方法的周围型早期肺癌CT图像增强研究

探讨增强早期肺癌CT图像的方法.采用小波变换增强图像细节的方法,根据图像特点,同时结合对比度自适应直方图均衡化或(和)自适应滤波去噪法,对10位早期周围型肺癌患者的50张CT图像进行增强.结果表明,处理后图像中肺内结节的边缘锐利、内部密度清晰、周围征象(如胸膜凹陷征等)清楚;各组织器官边缘清晰、层次明显,肺纹理清晰度增加.尤其是低对比度图像,处理后图像质量有较明显提高.基于小波变换结合其他预处理方法,对早期肺癌的CT图像进行增强,可为同类研究提供一定的参考.     

Die Spektralanalyse des EKG zur Erkennung von Spätpotentialen als Marker für die Gefährdung durch bedrohliche Rhythmusstörungen des Herzens

Summary Late potentials in the terminal phase of the QRS and early S-T segment are looked upon as a risk marker in patients prone to sustained ventricular tachycardia after myocardial infarction. Since the amplitude of late potentials at the body surface is very low (1–5 V), most studies use signal averaging of the ECG to increase the signal-to-noise ratio. Two different approaches are generally used to analyze the signal-averaged ECG. In the time domain, the individual channels are combined into a vector magnitude and highpass filtered in a bidirectional mode. Late potentials are suspected if the filtered QRS duration is >120 ms and/or the amplitude in the terminal 40 ms of the QRS complex is 25 V. The limitations of this method are that the definition of abnormality differs from one study group to another, highpass filters may introduce artificial signals, patients with bundle branch block in general have to be excluded, and the definitions depend upon the noise level.More recently, spectral analysis of the ECG with Fast Fourier Transform (FFT) has been performed. Late potentials are characterized by a higher frequency content in the otherwise low-frequent S-T wave. We analyzed 25 overlapping segments of the terminal QRS and early S-T wave time shifted in steps of 2 ms with FFT (spectrotemporal mapping). This method was shown to overcome some of the limitations of conventional time domain analysis: no highpass filters have to be applied, noise interference can be detected by a characteristic spectral pattern, and patients with bundle branch block need not be excluded. In this retrospective study spectrotemporal mapping was abnormal in 26/38 patients (67%) after myocardial infarction with sustained ventricular tachycardia.Only 3/21 patients after myocardial infarction without ventricular tachycardia had abnormal values. In healthy persons an abnormal Fourier result is a rare finding.Thus, spectral analysis of the ECG might offer promise for an improved identification of patients prone to sustained ventricular tachycardia after myocardial infarction.

---

Abkürzungsverzeichnis FFT schnelle Fourier Transformation - RMS Amplitude mittlere Amplitude in den terminalen 40 ms des QRS Komplexes in V Herrn Professor Dr. F. Scheler zum 65. Geburtstag gewidmet.     

Tuning the power spectrum of physiological finger tremor frequency with flickering light

Fast Fourier Transform analyses were performed on finger tremor movements at 0.2-Hz intervals from 0.4 to 40 Hz in 10 human subjects, under a flickering light condition of 4-15 Hz and an unstimulated control condition. Under the control condition, the power spectrum showed an essentially normal curve distribution, except for an early frequency component in the histogram. In contrast, when the flickering light stimulus was presented, the power of specific frequency components at 8-11 Hz was strongly enhanced. This effect was induced exclusively at a frequency of 8, 9, or 11 Hz of flickering light, and this flickering frequency producing the enhancement effect differed from subject to subject. There existed a significant correlation between the frequencies of flicker and tremor at the tuned frequency. These findings demonstrate that a specific frequency of flickering light can intensify a specific frequency of physiological finger tremor, and that different individuals exhibit different optimal "tuning" frequencies.     

Long-term drug delivery using implantable electrospun woven polymeric nanotextiles

A woven nanotextile implant was developed and optimized for long-term continuous drug delivery for potential oncological applications. Electrospun polydioxanone (PDS) nanoyarns, which are twisted bundles of PDS nanofibres, were loaded with paclitaxel (PTX) and woven into nanotextiles of different packing densities. A mechanistic modeling of in vitro drug release proved that a combination of diffusion and matrix degradation controlled the slow PTX-release from a nanoyarn, emphasizing the role of nanostructure in modulating release kinetics. Woven nanotextiles, through variations in its packing density and thereby architecture, demonstrated tuneable PTX-release. In vivo PTX-release, pharmacokinetics and biodistribution were evaluated in healthy BALB/c mice by suturing the nanotextile to peritoneal wall. The slow and metronomic PTX-release for 60 days from the loosely woven implant was extremely effective in enhancing its residence in peritoneum, in contrast to intraperitoneal injections. Such an implantable matrix offers a novel platform for therapy of solid tumors over prolonged durations.