以傅里叶变换红外光谱学检测结肠癌组织标本诊断结肠癌

Background The survival of cancer patients primarily depends on early detection of cancer. Fourier transform infrared spectroscopy (FT-IR) combined with chemometrics discriminant analysis technology could improve diagnosis. The present study aimed to evaluate the effects of FT-IR on Malignant Colon Tissue Samples on diagnosis of colorectal cancer. Methods Principal component analysis and support vector machine classification were used to discriminate FT-IR spectra from malignant and normal tissue. Colon tissues samples from 85 patients were used to demonstrate the procedure. Results For this set of colon spectral data, the sensitivity and specificity of the support vector machine (SVM) classification are both higher than 90%. Conclusions FT-IR provided important information about cancerous tissue, which could be used to discriminate malignant from normal tissue. The combination of principal component analysis (PCA) and SVM classification indicates that FT-IR has a potential clinical application in diagnosis of colon cancer.     

基于函数映射机制的鲁棒性二重数字水印算法

针对二重数字水印嵌入信息量相对较大及其水印之间相互干扰的特点,提出了一种基于函数映射机制的二重数字水印算法。将第一、二重水印建立某种函数映射关系,在嵌入水印时,只需嵌入一份水印样本,并结合小波变换、离散余弦变换和奇异值分解技术,将水印嵌入在寄主图像中。仿真实验结果表明：该算法不仅具有很好的透明性,而且对各种常规数字信号处理和几何攻击也有很强的鲁棒性。     

天然与合成紫晶的光谱学特征及其呈色机理

采用X射线荧光光谱(XRF)、紫外可见光光谱(UV-Vis)、红外光谱(FT-IR)和拉曼光谱(RM)多种光谱学分析方法对天然与合成紫晶样品进行测试。XRF结果显示,天然与合成紫晶的成分均为w=99 % SiO₂,分别含有致色的Fe元素和其他微量金属杂质;红外光谱图显示天然紫晶在3 560~3 200 cm^-1区间内有一强宽吸收带,合成紫晶在3 600~3 000 cm^-1 区间内有2个较尖锐的水吸收峰,分别位于3 583 cm^-     

基于张量形态学梯度和图像森林化变换分水岭算法的扩散张量图像脑白质分割

目的 基于张量形态学梯度和图像森林化变换分水岭算法,提出一种从脑扩散张量图像中分割出白质组织的方法,并验证其是否快速、有效.方法 首先总结了几种张量相似性函数,进一步计算张量形态梯度,再利用基于图像森林化变换分水岭算法对脑扩散张量图像进行白质组织的分割.结果 采用此方法对志愿者的脑扩散张量图像进行分割,得到了较好结果....     

幽默7则

新人妙语一对新人结婚前夕,在一个风景秀美的公园里拍婚纱照。拍摄时,身着婚纱的新娘和身着西服的新郎在摄影师的导演下,要不断变换摄     

小波变换在微弱生命信号处理中的应用

小波变换是时间和频率的局部变换,它在多领域的研究都取得了有科学意义和应用价值的成果。本文对小波变换作了简要介绍,对小波变换在微弱生命信号中的应用进行了初步探讨。     

黑胡椒挥发油的FTIR鉴定与GC-MS分析

目的 分析黑胡椒挥发油的化学成分,以控制其质量.方法 用水蒸气蒸馏法提取挥发油后,采用傅立叶变换红外光谱法(FTIR)和气相色谱-质谱法(GC-MS)分析.结果 在4批黑胡椒挥发油的FTIR图谱20个峰中有11个共有峰;GC-MS分析每个样品鉴定了19-24种化学成分.主要挥发性成分是单萜类,倍半萜及其氧化物,但4批样...     

傅里叶变换红外光谱法快速鉴别虎掌南星

目的:研究虎掌南星的红外光谱鉴别方法。方法:利用傅里叶变换红外光谱法,研究不同产地和不同生境虎掌南星及其提取物的红外谱图特征。结果:在2000～700cm-1波长区间,虎掌南星红外特征吸收峰明显。结论:本方法快速、准确,红外图谱谱峰显著,具有特征性,可用于虎掌南星药材的快速鉴别。     

小波变换在医学图像去噪中的应用研究

对医学图像进行去噪可以提高医学图像的信息利用率,小波变换是目前最新的时频分析工具,是图像去噪的强有力处理工具。提出了一种基于小波变换的去噪方法,实验证明,该去噪方法能有效去除医学图像中的噪声。     

Preliminary study on MR colonography with air enema in detection of colorectal neoplasms

Background The few studies on MR colonography with air enema involved feasibility of bowel distention and imaging quality and lacked detection sensitivity of colorectal neoplasms. The purpose of this prospective study was to assess the detection sensitivity of colorectal neoplasms with the three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema. Methods A total of 30 patients scheduled for optical colonoscopy due to rectal bleeding, positive fecal occult blood test results or altered bowel habits were recruited and successfully underwent entire colorectal examinations with three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography and subsequent optical colonoscopy on the same day. Detection sensitivity of colorectal neoplasms with MR colonography was statistically analyzed on a per-neoplasm size basis by using findings from optical colonoscopy and histopathological examinations as the reference standards. Results Seventy-six neoplasms were detected with optical colonoscopy, consisting of 1 mm-5 mm （n=11）, 6 mm-9 mm （n=29） and 〉10 mm （n=-36） in diameter. Detection sensitivities of 1 mm-5 mm, 6 mm-9 mm, 〉10 mm and 〉6 mm colorectal neoplasms with MR colonography were 9.1%, 75.9%, 100% and 89.2%, respectively; overall detection sensitivity for all sizes colorectal neoplasms was 77.6%. Conclusions Detection sensitivity of three-dimensional Fourier transform fast spoiled gradient-recalled MR colonography with air enema is low for 1 mm-5 mm colorectal neoplasms, but the detection sensitivity is 89.2% for ≥6 mm neoplasms, and all ≥10 mm neoplasms could be detected.