The study of micro-motion amplification technology has been widely concerned. Eulerian Video Magnification is one of the methods of concern and affirmation. Ischemia refers to the lack of blood flowing in certain parts of the body, which can occur in the limb, heart, brain or other parts of the body. Ischemia is a serious disease, which can cause serious tissue damage or let limbs not move. In this paper, we use Eulerian Video Magnification to initially detect whether someone suffers from limb ischemia by amplifying the movement of limb blood.
Nonlinear optical spectroscopy has wide applications in the medical field with special advantages. Through combining nonlinear optical spectroscopy with membrane electrophoresis, we endeavored to develop a novel method for blood serum analysis for cancer detection applications. In this method, albumin and globin are isolated from blood serum by membrane electrophoresis to perform two-photon excitation fluorescences (TPEF) spectral analysis. The obtained spectra present rich signatures of the biochemical constituents of whole proteins. We evaluated the utility of this method by analyzing albumin and globin samples of blood serum from esophageal cancer patients and healthy volunteers. Twophoton excitation fluorescences revealed that esophageal cancer group can be unambiguously discriminated from the normal group, and I457/I639, I511/I639, and I543/I639 ratios can be used as indicators to diagnose early esophageal cancer. These results are very promising for developing a label-free, non-invasive clinical tool for early cancer detection and screening.
Secreted proteins, the promising source of biomarkers for early detection and diagnosis of cancer, have received considerable attention. Raman spectroscopy and principal component analysis (PCA) were used to characterize the secreted proteins collected from the cell cultures of human hepatoma cell line HepG2 and normal human liver cell line LO2 in this paper. We found the major difference of secreted proteins Raman spectra between HepG2 and LO2 cells were in the range of 1200cm-1-1800cm-1. Compared with LO2 cells, some significant changes based on secondary structure of secreted proteins in HepG2 cells were observed, including the increase in the relative intensity of the band at 1004cm-1, 1445cm-1, 1674cm-1 and the decrease at 1074cm-1. These variations of Raman bands indicated that the species and conformation of secreted proteins in HepG2 cells changed. The measured Raman spectra of the two groups were separated into two distinct clusters with no overlap and high specificity and sensitivity by PCA. These results show that the combination of Raman spectroscopy and PCA analysis may be a powerful tool for distinguishing the secreted proteins between human hepatoma cells and normal human liver cells, provide a new thought to analyze the secreted proteins from cancer cells and find a novel cancer biomarker.
Gold nanoparticles are delivered into living cells by transient electroporation method to obtain intracellular surface-enhanced Raman spectroscopy (SERS). The subcellular localization of gold nanoparticles is characterized by transmission electron microscopy, and the forming large gold nanoaggregates are mostly found in the cytoplasm. The SERS detection of cells indicates that this kind of gold nanostructures induces a high signal enhancement of cellular chemical compositions, in addition to less cellular toxicity than that of silver nanoparticles. These results demonstrate that rapid incorporation of gold nanoparticles by electroporation into cells has great potential applications in the studies of cell biology and biomedicine.
The use of normal Raman (NR) spectroscopy and surface enhanced Raman scattering (SERS) spectroscopy to analyze the biochemical information of human serum proteins and hence distinguish between normal and primary hepatic carcinoma (PHC) serum samples was investigated. The serum samples were obtained from patients who were clinically diagnosed with PHC (n=20) and healthy volunteers (n=20). All spectra were collected in the spectral range of 400-1800 cm-1 and analyzed through the multivariate statistical methods of principal component analysis (PCA). The results showed that both NR and SERS combined with PCA had good performance in distinguishing the human serum proteins between PHC patients and healthy volunteers with high sensitivity and specificity of 100%. And we can get more detail information of component and conformation of human serum proteins by considering NR and SERS spectrum. Our results support the concept again that serum protein Raman and SERS spectroscopy combined with PCA analysis both can become noninvasive and rapid diagnostic tools to detect the primary hepatic carcinoma.
Surface-enhanced Raman scattering (SERS) spectroscopy combined with membrane electrophoresis (ME) was firstly employed to detect albumin variation in type II diabetic development. Albumin was first purified from human serum by ME and then mixed with silver nanoparticles to perform SERS spectral analysis. SERS spectra were obtained from blood albumin samples of 20 diabetic patients and 19 healthy volunteers. Subtle but discernible changes in the acquired mean spectra of the two groups were observed. Tentative assignment of albumin SERS bands indicated specific structural changes of albumin molecule with diabetic development. Meanwhile, PCA-LDA diagnostic algorithms were employed to classify the two kinds of albumin SERS spectra, yielding the diagnostic sensitivity of 90% and specificity of 94.7%. The results from this exploratory study demonstrated that the EM-SERS method in combination with multivariate statistical analysis has great potential for the label-free detection of albumin variation for improving type II diabetes screening.
Despite the introduction of high-technology methods of detection and diagnosis, screening of primary liver cancer (PLC) remains imperfect. To diagnosis PLC earlier, Surface-enhanced Raman spectroscopy (SERS) coupled with cellulose-acetate membrane electrophoresis were introduced to separate human serum albumin and SERS spectra. Three groups (15 normal persons’ samples, 17 hepatitis/cirrhosis samples, 15 cases of PLC) of serum albumin were tested. Silver colloid was used to obtain SERS spectra of human serum albumin. Principal component analysis (PCA) and linear discriminant analysis (LDA) were also employed for statistical analysis. The mean Raman spectra of three groups and the difference spectra of any two suggested that the albumin has changed in liver patients. Compared to normal groups, some Raman peaks have shifted or even disappeared in hepatitis/cirrhosis and PLCs groups. The sensitivity and specificity between PLCs and normal groups is 80% and 93.3%. Among hepatitis/cirrhosis and normal groups, the sensitivity is 88.2% and specificity is also 93.3%. Besides, the sensitivity and specificity between PLCs and hepatitis/cirrhosis groups is 86.7% and 76.5%. All the above data and results indicated that early screening of PLC is potential by SERS in different stages of liver disease before cancer occurs.
Surface-enhanced Raman scattering (SERS) spectra of serum proteins purified from human serum samples were employed to detect colorectal cancer. Acetic acid as a new aggregating agent was introduced to increase the magnitude of the SERS enhancement. High-quality SERS spectra of serum proteins were acquired from 103 cancer patients and 103 healthy volunteers. Tentative assignments of SERS bands reflect that some specific biomolecular contents and protein secondary structures change with colorectal cancer progression. Principal component analysis combined with linear discriminant analysis was used to assess the capability of this approach for identifying colorectal cancer, yielding diagnostic accuracies of 100% (sensitivity: 100%; specificity: 100%) based on albumin SERS spectroscopy and 99.5% (sensitivity: 100%; specificity: 99%) based on globulin SERS spectroscopy, respectively. A partial least squares (PLS) approach was introduced to develop diagnostic models. An albumin PLS model successfully predicted the unidentified subjects with a diagnostic accuracy of 93.5% (sensitivity: 95.6%; specificity: 91.3%) and the globulin PLS model gave a diagnostic accuracy of 93.5% (sensitivity: 91.3%; specificity: 95.6%). These results suggest that serum protein SERS spectroscopy can be a sensitive and clinically powerful means for colorectal cancer detection.
In this paper, microstructures of human esophageal mucosa were evaluated using the two-photon laser scanning confocal microscopy (TPLSCM), based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). The distribution of epithelial cells, muscle fibers of muscularis mucosae has been distinctly obtained. Furthermore, esophageal submucosa characteristics with cancer cells invading into were detected. The variation of collagen, elastin and cancer cells is very relevant to the pathology in esophagus, especially early esophageal cancer. Our experimental results indicate that the MPM technique has the much more advantages for label-free imaging, and has the potential application in vivo in the clinical diagnosis and monitoring of early esophageal cancer.
Multiphoton microscopy (MPM), a noninvasive optical method with high resolution and high sensitivity, can obtain
detailed microstructures of biotissues at submolecular level. In this study, MPM is used to image microstructure varieties
of human colonic mucosa and submucosa with adenocarcinoma. Some parameters, such as gland configuration,
SHG/TPEF intensity ratio, and collagen orientation and so on, should serve the indicators of early colorectal cancer. The
exploratory results show that it's potential for the development of multiphoton mini-endoscopy in real-time early
diagnosis of colorectal cancer.
Due to its high sensitivity, flexibility, and “fingerprints” sensing capability, Surface-enhanced Raman Spectroscopy
(SERS) is a very powerful method for characterization of substances. In this paper, two kinds of Radix Astragali with
different quality were firstly extracted through continuous circumfluence extraction method and then mixed with silver
nanoparticles for SERS detection. Most Raman bands obtained in Radix Astragali extraction solution are found at
300-7000cm-1 and 900-1390 cm-1. Although, major peak positions at 470, 556, 949, 1178 and 1286 cm-1 found in these
two kinds of Radix Astragali appear nearly the same, Raman bands of 556 and 1178 cm-1 are different in intensity, thus
may be used as a characteristic marker of Radix Astragali quality. In detail, we can make full use of the different
intensity of two different kinds but the same state at 556 cm-1 to describe the quality standard of Radix Astragali. Our
preliminary results show that SERS combining with continuous circumfluence extraction method may provide a direct,
accurate and rapid detection method of Radix Astragali.
A novel method for rapidly synthesized Au colloidal under microwave irradiation was present in this paper. Size of the
Au nanoparticles varied from 10 nm to 60 nm along with varying mol fractions by chloroauric acid solution reduced with
sodium citrate. The prepared Au nanoparticles were characterized by transmission electron microscope (TEM) and
ultraviolet-visible (UV-Vis) spectrophotometer. It is found that the nanoparticle size and shape are highly dependent on
the reaction time and the molar ratios of the reducing agent. By the SERS measurements of R6G, 4-MBA and Crystal
violet, this Au colloid is shown to be an excellent SERS substrate with good stability. As the fabrication process of this
SERS substrate is simple and inexpensive, this method may be used in large-scale preparation of substrates that can serve
as an ideal SERS substrate in biomedical application.
Second harmonic generation (SHG) is a well-known physical phenomenon of important in nonlinear optics, which has
been widely used in tissue morphology and pathology. In this thesis, the influences on backward SHG intensity were
studied. A two-photon laser scanning confocal microscope coupled with a mode-locked femtosecond Ti: sapphire laser
was used to carry out the experiments. Rat-tails were used as experimental objects, there were 40 slices including
transverse and longitudinal. All slices were un-dyed. The changes of backward SHG intensities of rat-tails versus the
excited wavelengths, excited powers, exploring-depths and so on were obtained. It was clear that different irradiation
conditions had evident influences on backward SHG intensity. Subsequently, the backward SHG imaging and
two-photon excited fluorescence (TPEF) imaging through two independent channels were also compared preliminarily.
This study demonstrates that SHG is a promising tool for more accurate information in biomedicine fields.
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