Research and application of Raman spectroscopy in the diagnosis and therapy of brain glioma / 中华核医学与分子影像杂志

Brain glioma invariably relapses since the tumor is difficult to remove completely. Accurate identification of tumor subtypes and tracing of tumor boundaries intraoperatively are the key clinical issues. Raman spectroscopy has a good application prospect in the intraoperative diagnosis of brain glioma due to its advantages of nondestructive, label-free, histology imaging and high specificity. In this article, the research and application of Raman spectroscopy in the in vitro diagnosis and intraoperative navigation-related diagnosis and treatment of brain glioma are reviewed.

[Application of Raman-based technologies in the detection of urological tumors].

Urinary system tumors affect a huge number of individuals, and are frequently recurrent and progressing following surgery, necessitating lifelong surveillance. As a result, early and precise diagnosis of urinary system cancers is important for prevention and therapy. Histopathology is now the golden stan-dard for the diagnosis, but it is invasive, time-consuming, and inconvenient for initial diagnosis and re-gular follow-up assessment. Endoscopy can directly witness the tumor's structure, but intrusive detection is likely to cause harm to the patient's organs, and it is apt to create other hazards in frequently examined patients. Imaging is a valuable non-invasive and quick assessment tool; however, it can be difficult to define the type of lesions and has limited sensitivity for early tumor detection. The conventional approaches for detecting tumors have their own set of limitations. Thus, detection methods that combine non-invasive detection, label-free detection, high sensitivity and high specificity are urgently needed to aid clinical diagnosis. Optical diagnostics and imaging are increasingly being employed in healthcare settings in a variety of sectors. Raman scattering can assess changes in molecular signatures in cancer cells or tissues based on the interaction with vibrational modes of common molecular bonds. Due to the advantages of label-free, strong chemical selectivity, and high sensitivity, Raman scattering, especially coherent Raman scattering microscopy imaging with high spatial resolution, has been widely used in biomedical research. And quantity studies have shown that it has a good application in the detection and diagnosis of bladder can-cer, renal clear cell carcinoma, prostate cancer, and other cancers. In this paper, several nonlinear imaging techniques based on Raman scattering technology are briefly described, including Raman spectroscopy, coherent anti-Stokes Raman scattering, stimulated Raman scattering, and surface-enhanced Raman spectroscopy. And we will discuss the application of these techniques for detecting urologic malignancy. Future research directions are predicted using the advantages and limitations of the aforesaid methodologies in the research. For clinical practice, Raman scattering technology is intended to enable more accurate, rapid, and non-invasive in early diagnosis, intraoperative margins, and pathological grading basis for clinical practice.

To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer / 中华检验医学杂志

Objective:To establish a method of serum detection by Raman spectroscopy for the diagnosis of gastric cancer.Methods:Between April and November 2019, 110 patients with gastric cancer [73 males, 37 females, age (57.4±10.3) years] and 74 patients with colorectal cancer [48 males and 26 females, aged (58.3±12.2) years] were collected at the First Affiliated Hospital of Army Military Medical University, along with 100 healthy subjects [59 males and 41 females, aged (55.6±10.61) years] during the same period. Fasting venous blood serum samples were collected from the subjects. A Raman spectrometer XploRA PLUS was used in this experiment, with an excitation light source of 532 nm, a field of view of 100 times, and a spectrum range of 200-2 000 cm -1, etc. The serum samples were detected by nondestructive and non-contact rapid detection, and the Raman spectra of serum samples were collected. Using the Raman spectrum acquisition and processing supporting software LabSpec6 to smooth, baseline, and normalize the obtained Raman spectrum. Multivariate statistical analysis software SIMCA14.1 were applied to import and analyze the obtained Raman spectrum data by principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and other methods for statistical analysis. An operating characteristic curve (ROC) was constructed to evaluate the model analysis effect between serum samples of healthy people and those with gastric cancer. Serum samples from the colorectal cancer group were used to verify the reliability of the model. Results:Six Raman peaks with good repeatability were detected in serum samples in health and gastric cancer group, and peaks were located at 1 001.17, 1 154.63, 1 337.89, 1 446.85, 1 515.33, and 1 658.34 cm -1, respectively. Raman intensities at six Raman peaks were significantly different between healthy and gastric cancer groups. At the displacement of 1 001.17, 1 154.63, and 1 515.33 cm -1, the Raman intensity in the healthy group was higher than that in the gastric cancer group. At 1 337.89, 1 446.85, and 1 658.34 cm -1 displacement, the Raman intensity of the gastric cancer group was higher than that of the healthy group. An OPLS-DA model was constructed to analyze the serum samples of the healthy group and the gastric cancer group. In the model, R 2 is the fitting power, and Q 2 is the predictive ability. The closer the values of R 2 and Q 2 are to 1, the better the performance of the model, and the obtained model's R 2X(cum)=0.809, R 2Y(cum)=0.819, Q 2(cum)=0.758. ROC characteristic curve was drawn based on the OPLS-DA model. The area under the curve (AUC) of the gastric cancer group was 0.998. Six peaks with good repeatability were detected in the serum Raman spectra of gastric cancer stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ, which were located at the displacement of 1 001.85, 1 155.07, 1 338.36, 1 445.75, 1 515.92, and 1 657.68 cm -1, respectively, and at the displacement of 1 155.07 and 1 515.92 cm -1. The Raman intensity of gastric cancer stage Ⅳwas significantly higher than that of gastric cancer stages Ⅰ, Ⅱ, and Ⅲ. Conclusions:According to the model reliability verification, the healthy group, gastric cancer group and colorectal cancer group can also be effectively separated based on OPLS-DA results; it showed a good performance in separating the healthy group from the gastric cancer group. It is possible to detect serum samples from healthy people and gastric cancer patients unlabeled by combining Raman spectroscopy and the OPLS-DA method in multivariate statistics.

Rapid detection method for identifying and distinguishing Candida auris and its relatives by surface-enhanced Raman spectroscopy / 中华检验医学杂志

Objective:To develop an accurate, specific and rapid and non-destructive technique for the identification of Candida auris and its relatives without destroying the cell wall. Methods:The study was conducted in Beijing Institute of Radiation Medicine in 2021. Surface-enhanced Raman spectroscopy (SERS) substrates were prepared by sodium citrate reduction. Through SERS, the collected SERS fingerprint spectra were analyzed by orthogonal partial least-squares-discrimination analysis (OPLS-DA) using SIMCA 14.1 (Umetrics, Sweden). Four strains of Candida auris, 4 strains of Candida heamulonii, 3 strains of Candida pseudohaemulonii and 4 strains of Candida duobushaemulonii were effectively identified and distinguished. Results:Within the 95% confidence interval, the sample analysis results presented an oval. The four Candida species detected in this study could be well separated. R2X(cum)=0.629, R2Y(cum)=0.947, Q2(cum)=0.915. R2X, R2Y and Q2 all>0.5 and closed to 1, suggesting that the model in this study was well established, and had good prediction ability. The results of the 10-fold-cross validation showed that the accuracy of both the model training data and test data are 100%, indicating that the model established in this research had good classification capabilities. Conclusions:This research has developed a new technique that can identify Candida auris and its relatives in a highly accuracy, specific and rapid way without destroying the cell wall. Being cost-effective and easy to operate, this technique has great potential to be applied in clinical fungal testing.

[Lab on a Chip]. / "Lab on a Chip".

BACKGROUND: Miniaturization has not only driven microelectronics and generated new unforeseen options but has also dramatically changed sensors and analytics. DEVELOPMENTS: The Lab on a Chip (LOC) technology enables laboratory processes to run fully automated in canals in the micrometre range. The biggest challenge for LOC is to keep production costs low despite miniaturization and application-specific design. If this is achieved medical laboratory analyses can usually be carried out faster and with less hands on time. This explains why LOCs are already integrated into many laboratory instruments and why point-of-care testing (POCT) can no longer be imagined without it. New markers, such as in liquid biopsies and measurement techniques, such as Raman spectroscopy and mass spectroscopy, create further potentials that will enable faster and more specific laboratory analyses to be made using LOC technology. CONCLUSION: The LOC technology has the potential of changing the medical practice especially in cases when the central laboratory is not available or is unable to provide results fast enough.

Surface-enhanced Raman nanoparticles for cancer theranostics / 中华核医学与分子影像杂志

Raman spectroscopy is amplified by surface-enhanced Raman scattering nanoparticles(SERS-NPs),and Raman signal can be enhanced by SERS-NPs,which can achieve high-resolution imaging of tumors.Meanwhile,SERS-NPs have high molecular specificity and sensitivity,showing a good prospect of tumor diagnosis and treatment.The advantages of SERS-NPs and its application in tumor diagnosis and treatment,and related experimental studies are reviewed in this article.

Efeitos de protocolos excessivos associados a produtos clareadores caseiros sobre a microestrutura, a composição e as propriedades físicas do esmalte dentário humano / Effects of excessive protocols associated with home bleaching products on the microstructure, composition and physical properties of human tooth enamel

As técnicas clareadoras são consideradas seguras, simples e não invasivas. Assim, ganharam popularidade entre profissionais e pacientes. No entanto, o livre acesso do gel à estrutura dentária e o contato direto com a superfície do esmalte levantam dúvidas sobre seus reais impactos. Novas preocupações surgiram com os chamados produtos de bancada e a possibilidade de auto-aplicação, inclusive com consumo exagerado e/ou sem orientação e acompanhamento. Sendo assim, buscou-se avaliar, os efeitos de produtos clareadores caseiros sobre microestrutura, rugosidade, composição, nanodureza e módulo de elasticidade do esmalte dentário humano, em protocolos de uso normal ou excessivo. Amostras obtidas de 10 terceiros molares foram divididas em 4 grupos: grupo I ­ armazenamento em saliva artificial, grupo II ­ utilização de peróxido de carbamida (PC) 10%, grupo III ­ utilização de peróxido de hidrogênio (H2O2) 10%, grupo IV ­ utilização de tiras clareadoras (H2O2 10%). Cada dente forneceu quatro fragmentos de esmalte para cada um dos grupos. Foram realizadas aplicações diárias de acordo com a recomendação dos fabricantes, e foi adotada simulação de escovação duas vezes ao dia com escova elétrica. Todas as amostras foram armazenadas em saliva artificial e passaram por análises antes do início da terapia, após 4 e 8 semanas de intervenção. A escolha por técnicas não-destrutivas permitiu que cada amostra fosse seu próprio controle. Desse modo, a microscopia confocal por varredura a laser e microscopia de força atômica avaliaram alterações na microestrutura da superfície e foram coletados dados de rugosidade (Sa e Sq) para análise estatística. Os espécimes passaram por testes de nanoindentação para avaliação de nanodureza e módulo de elasticidade. Essas informações foram correlacionadas com as alterações de composição por microespectroscopia Raman. O clareamento com PC não apresentou alterações significativas nas amostras de esmalte, seguindo o padrão de comportamento daquelas escovadas e armazenadas em saliva artificial, tendo se mostrado segura. No entanto, os grupos que passaram por intervenção com H2O2 (III e IV) apresentaram modificações significativas em suas propriedades após 4 e 8 semanas de utilização. A alteração na superfície com aparência mais exposta foi associada a maior detecção de proteínas após as primeiras 4 semanas de utilização, especialmente para o grupo III. Após 8 semanas, a superfície apareceu mais suave, com perda do padrão prismático e queda no conteúdo orgânico, sugerindo uma perda de camadas superficiais desorganizadas. Do mesmo modo, o aumento dos valores de dureza e módulo de elasticidade para essas amostras pareceu derivar do efeito remineralizador da saliva e do papel positivo das proteínas mais expostas nas propriedades mecânicas permitindo maior deslizamento dos cristais e acomodação frente às cargas. Conclui-se que o uso de géis a base de H2O2 deve ser cauteloso, seguindo as recomendações profissionais e que são necessários testes in situ e in vivo para confirmar as tendências observadas.

The bleaching techniques are considered safe, simple and non-invasive and thus have gained popularity among professionals and patients. However, the free access of the gel to dental structures and the direct contact with the surface of the enamel, during the whole treatment raises doubts, about its possible impacts. Concerns were also raised about the emergence of so-called over-the-counter products and the possibility of self-application that could lead to excessive consumption and / or lack of guidance and monitoring. The aim of this study was to evaluate the effects of home bleaching products on the microstructure, roughness, composition, nanohardness and elastic modulus of human dental enamel in protocols of normal or excessive use. Samples were obtained from 10 third molars and divided into 4 groups: group I - storage in artificial saliva, group II - treatment with 10% carbamide peroxide, group III - treatment with 10% hydrogen peroxide, group IV - treatment with whitening strips (10% hydrogen peroxide). Each tooth provided four enamel fragments for treatment in each one of the groups. Daily applications were performed according to the manufacturers' recommendations, and a brushing simulation was used twice a day with an electric brush. All samples were stored in artificial saliva at the treatment intervals and were analyzed before the start of therapy, after 4 and 8 weeks of intervention. The choice by non-destructive techniques allowed each sample to be its own control. Qualitative analyzes of microstructure alteration were carried out using confocal laser scanning microscopy and atomic force microscopy. Roughness data (Sa and Sq) were also obtained for statistical analysis. Nanoindentation tests were used to determine changes in the nanohardness and elastic modulus. All of this information was correlated with composition changes by Raman micro-spectroscopy. Carbamide peroxide bleaching showed no significant changes in enamel samples, following the behavior pattern of those brushed and stored in artificial saliva, and therefore considered safe. However, the groups treated with hydrogen peroxide (III and IV) showed significant modifications in their properties after 4 and 8 weeks of treatment. The change in surface with more exposed appearance was associated with greater protein detection after the first month of treatment, especially for group III. After 8 weeks, the surface appeared smoother, with reduction of prismatic pattern and drop in organic content, suggesting a loss of disorganized mineral surface layers. Likewise, the increase in hardness and elastic modulus values for these samples seems to derive from the remineralizing effect of saliva and the positive role of the most exposed proteins in the mechanical properties, allowing greater slip of the crystals and accommodation with the loads. These changes may not reach clinically perceptible patterns but reinforce the importance of dentists' supervision and monitoring, since in-vivo the patient may be exposed to other challenges that may worsen the impacts. It is concluded that the use of hydrogen peroxide gels in bleaching therapies should be under professional supervision and that in situ and in vivo tests are required to confirm the observed trends.

Raman Spectroscopy for the Endoscopic Diagnosis of Esophageal, Gastric, and Colonic Diseases.

Globally white-light endoscopy with biopsy sampling is the gold standard diagnostic modality for esophageal, gastric, and colonic pathologies. However, there is overwhelming evidence to highlight the deficiencies of an approach based predominantly on eyeball visualization. Biopsy sampling is also problematic due in part to excessive sampling and hence attendant cost. Various innovations are currently taking place in the endoscopic domain to aid operators in diagnosis forming. These include narrow band imaging which aims to enhance the surface anatomy and vasculature, and confocal laser endomicroscopy which provides real time histological information. However, both of these tools are limited by the skill of the operator and the extensive learning curve associated with their use. There is a gap therefore for a new form of technology that relies solely on an objective measure of disease and reduces the need for biopsy sampling. Raman spectroscopy (RS) is a potential platform that aims to satisfy these criteria. It enables a fingerprint capture of tissue in relation to the protein, DNA, and lipid content. This focused review highlights the strong potential for the use of RS during endoscopic gastroenterological examination.

Long Term Degree of Conversion of two Bulk-Fill Composites.

OBJECTIVES: To investigate the long-term development of the post-cure degree of conversion (DC) for two flowable bulk-fill composites. MATERIALS AND METHODS: Tetric EvoFlow Bulk Fill (TEFBF) and SDR were chosen due to their distinct compositional modifications that enable the decrease of translucency during polymerization and lower polymerization rate, respectively. DC was assessed using FT-Raman spectroscopy at the post-cure times of 0 h, 24 h, 7 d and 30 d. The post-cure behavior was analyzed by a mixed model ANOVA and partial eta-squared statistics. RESULTS: DC ranged from 61.3-81.1% for TEFBF and 58.9-81.6% for SDR. The initial (0 h) DC was significantly lower at a depth of 4 mm than at a depth of 1 mm (4.9% for SDR and 11.1% for TEFBF). Both materials presented a significant post-cure DC increase, up to 16.4% for TEFBF and 20.6% for SDR. The post-cure DC development was depth-dependent for TEFBF, but not for SDR. The post-cure DC increase was observed during 24 h for TEFBF and 7 d for SDR. CONCLUSIONS: Some of the bulk-fill composites may need longer times than the commonly accepted 24 h to reach the final conversion. This may be attributed to their compositional modifications that are mostly undisclosed by manufacturers. Our findings imply that investigations commonly performed 24 h post-cure may underestimate some of the bulk-fill composite properties, if these are affected by the slowly-developing DC. Reactive species may also be available for leaching out of the restoration during an extended time period, with possible implications on biocompatibility.

Ainda é necessário criar rugosidade na superfície da Y-TZP? / Is it still necessary to roughen the Y-TZP surface?

Problematização. As Zircônias tetragonais estabilizadas com ítria (Y-TZP) são amplamente utilizadas na confecção de próteses dentárias. Uma vez que é mais utilizada como infraestrutura, as cerâmicas de cobertura ainda mostram fraturas, resultando em redução da longevidade da prótese. Objetivo. Avaliar e testar a eficácia de tratamentos de superfície entre Y-TZP e cerâmica de cobertura antes da aplicação do liner. Material e métodos. Quarenta discos Y-TZP (12,5mm de diâmetro e 3,5mm de espessura) foram divididos em quatro grupos (n = 10): LC: aplicação exclusiva do liner; S40: sonicação pré-sinterizada com 40 % de potência nominal durante 15 minutos; S70: sonicação présinterizada com 70 % de potência nominal durante 15 minutos; JOX: jateamento com partículas de alumínio de 50µm. Após os tratamentos rugosos de superfície, o liner foi aplicado na superfície das amostras todos os grupos. Após a sinterização, os espécimes foram submetidos a Microscopia confocal de varredura a laser (CLSM) e Microscopia de força atômica (AFM) para avaliar a topografia e a rugosidade da superfície. As fases das estruturas cristalinas foram identificadas através de espectroscopia micro-Raman (MRS). Após esta etapa, a cerâmica de cobertura foi aplicada em todas as superfícies da Y-TZP e os espécimes foram submetidos ao teste de Resistência de união ao cisalhamento (SBS) a uma velocidade de 0,5mm/min até à fratura. Os modos de falha foram classificados como adesiva, coesiva ou mista. Os resultados de SBS foram submetidos a uma ANOVA a um critério (α = 0,05) seguido pelo teste de Tukey (α = 0,05). Resultados. Não foram observadas diferenças entre os grupos quanto à rugosidade superficial (0,255), embora as imagens da Microscopia Confocal e AFM apresentassem diferenças topográficas entre os grupos. O grupo LC apresentou maiores valores medianos de SBS, significativamente diferentes de S70 e JOX (p=0,008), os quais não foram diferentes. S40 apresentou os valores medianos de SBS mais baixos (15,43 Mpa). Todos os espécimes Y-TZP exibiram bandas típicas tetragonais e fases monoclínicas. A maioria dos espécimes de todos os grupos exibiram falhas mistas (67,5%) e os espécimes restantes exibiram falhas adesivas. Conclusão. Tratamentos de superfície adicionais para Y-TZP, jateamento e tratamento sonoquímico com potência de 70 % mostraram resultados semelhantes, mas não aumentaram a SBS para uma cerâmica de cobertura.(AU)

Statement of the problem. The yttria-stabilized tetragonal zirconia (Y-TZP) ceramics are widely used manufacturing of dental prostheses. Since it is most used as framework, the ceramics veneers still show fractures, resulting in reduction of longevity of the prosthesis. Objective. Evaluate and test the effectiveness of roughening treatments between Y-TZP and veneering ceramic before liner application. Material and methods. Forty Y-TZP discs (12.5mm Ø and 3.5mm thickness) were divided in four groups (n = 10): LC: application of the proprietary liner only; S40: pre-sintered sonication with 40 % nominal power for 15 minutes; S70: pre-sintered sonication with 70 % nominal power for 15 minutes; JOX: sandblasting with 50 µm aluminum particles. After roughening treatments, the liner was applied to the surface of the samples in all groups. After sintering, the specimens were subjected to confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) analyses to evaluate the topography and surface roughness. The phases of the crystalline structures were identified through micro-Raman spectroscopy (MRS). After that, a veneering ceramic was applied to all Y-TZP surfaces and subjected to shear bond strength (SBS) testing at a speed of 0,5mm/min until fracture. Failure modes were classified as adhesive, cohesive, or mixed. SBS results were subjected to one-way ANOVA (α = 0.05) followed by Tukey's test (α = 0.05). Results. No differences were shown between groups regarding surface roughness (p=0,255), although Confocal and AFM images showed topographical differences among groups. The LC group showed the highest SBS median values, which were significantly different from S70 and JOX (p=0,008), which were not different. S40 showed the lowest SBS median values (15,43 MPa). All specimens exhibited typical Y-TZP tetragonal bands and monoclinic phases. Most specimens of all groups exhibited mixed failures (67,5%) and the remaining specimens exhibited adhesive failures. Conclusion. Additional surface treatments for Y-TZP, sandblasting, and 70 % power sonochemical treatment showed similar results but did not increase SBS to a feldspathic ceramic.(AU)

Application of surface-enhanced raman spectroscopy in human serum / 军事医学

Recently surface-enhanced Raman spectroscopy (SERS) has been widely used in physics, chemistry and bio-medical science.Due to its high sensitivity and specificity,SERS is often used to detect changes in serum components in humans.Various biomolecules in human serum, such as proteins, lipids and nucleic acids, have their own distinctive raman spectroscopy so that different raman shift, band intensity and width reflect different metabolic abnormalities of cells at the molecular level in human serum.In this paper we described the general situation of SERS and summarized the latest research progress in a variety of diseases of human serum.Prospects of developmenls are also outlined.

Mechanism of Escherichia coli injury under UV disinfection / 军事医学

Objective To study the inactivation kinetics and injury mechanism of Escherichia coli under UV disinfection in drinking water.Methods The inactivation kinetics of E.coli ATCC 25922 was determined by plate count methods in the UV disinfection experiment.The morphology,cell membrane permeabilization and injury of biological macromolecules were observed under a transmission electron microscope (TEM).The rate of ONPG hydrolysis and changes in activities of antioxidant enzymes were observed Raman spectroscopy.Results the changes of damaged cells involved morphological damage such as loss of the structural integrity of the wall and membrane,condensation of cellular material and leakage of significant amounts of cytoplasmic material,a more than four-fold increase of cell membrane permeabilization and damage to the structure of protein,nucleic acids and phospholipid.Conclusion UV disinfection can lead to a multi-target damage.

Serum fingerprint detection based on surface-enhanced Raman scattering / 军事医学

Objective To optimize the experiment conditions of surface-enhanced Raman spectroscopy detection of serum fingerprint spectra.Methods Normal human serum was used as the sample and Ag nanoparticles as the active substrate.The enhanced signals of different optimized experiments were obtained , including serum dose(2.5 to 500 μl), incubation time(10 to 30 minutes) temperature(4℃,room temperature and 37℃),and different treatment(extraction and protein removal).Results and Conclusion Serum doses should not exceed 50μl.The ratio should range from 1∶1 to 5∶1, the incubation time is from 10 to 30 minutes, and the incubation temperature from 4℃ to 37℃.The signals of samples directly mixed with an active substrate are stronger than those of samples which are extracted or protein removed .

Alkanethiol modified magnetic silver flower nanoparticles applied to detection of chloramphenicol / 军事医学

Objective To prepare novel alkanethiol modified magnetic silver flower nanoparticles as SERS substrate to chloramphenicol for Raman detection and to determine their enhancement effect.Methods An alkanethiol was chosen as a surface modifier of the substrate and was self-assembled onto the magnetic silver flower nanoparticle surface.The chloram-phenicol molecules were enriched to the surface of the substrate by hydrophobic interaction and the effect for detection of chloramphenicol SERS signal was enhanced.Results It was found that the 1-hexanethiol-modified SERS substrate was able to lead to stronger enhancement than 1-dodecanethiol and octadecanethiol.Fe3 O4@SiO2-Ag-C6 was used to detect the chloramphenicol (10 -3 -10 -10 mol/L) and chloramphenicol in milk (10 -3 -10 -9 mol/L) by surface-enhanced Raman spectroscopy.The detection limits were 0.1 nmol/L (32 ppt) and 1 nmol/L (323 ppt) respectively.Conclusion Alkanethiol modified magnetic silver flower nanoparticles are a highly active SERS substrate, which can be used for detection of low concentrations of analytical substances.

Raman Spectroscopy for the Endoscopic Diagnosis of Esophageal, Gastric, and Colonic Diseases

Globally white-light endoscopy with biopsy sampling is the gold standard diagnostic modality for esophageal, gastric, and colonic pathologies. However, there is overwhelming evidence to highlight the deficiencies of an approach based predominantly on eyeball visualization. Biopsy sampling is also problematic due in part to excessive sampling and hence attendant cost. Various innovations are currently taking place in the endoscopic domain to aid operators in diagnosis forming. These include narrow band imaging which aims to enhance the surface anatomy and vasculature, and confocal laser endomicroscopy which provides real time histological information. However, both of these tools are limited by the skill of the operator and the extensive learning curve associated with their use. There is a gap therefore for a new form of technology that relies solely on an objective measure of disease and reduces the need for biopsy sampling. Raman spectroscopy (RS) is a potential platform that aims to satisfy these criteria. It enables a fingerprint capture of tissue in relation to the protein, DNA, and lipid content. This focused review highlights the strong potential for the use of RS during endoscopic gastroenterological examination.

Comparison of the Chemical Composition of Subchondral Trabecular Bone of Medial Femoral Condyle between with Advanced Osteoarthritis and without Osteoarthritis.

BACKGROUND: The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur. METHODS: Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs. RESULTS: The maximum intensity of the phosphate peak was 2,376.51±954.6 for the non-OA group and 1,936.3±831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different (P=0.017). The maximum intensity of the amide I peak were 474.17±253.42 for the nonOA group and 261.91±205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups (P=0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity (P=0.027, P=0.014, P=0.012; P=0.038, P=0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different (P=0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens. CONCLUSIONS: The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.

Multimodal and multiplex spectral imaging of rat cornea ex vivo using a white-light laser source.

We applied our multimodal nonlinear spectral imaging microscope to the measurement of rat cornea. We successfully obtained multiple nonlinear signals of coherent anti-Stokes Raman scattering (CARS), third-order sum frequency generation (TSFG), and second harmonic generation (SHG). Depending on the nonlinear optical processes, the cornea tissue was visualized with different image contrast mechanism simultaneously. Due to white-light laser excitation, multiplex CARS and TSFG spectra were obtained. Combined multimodal and spectral analysis clearly elucidated the layered structure of rat cornea with molecular structural information. This study indicates that our multimodal nonlinear spectral microscope is a promising bioimaging method for tissue study. Multimodal nonlinear spectral images of rat cornea at corneal epithelium and corneal stroma in the in-plane (XY) direction. With use of the combinational analysis of different nonlinear optical processes, detailed molecular structural information is available without staining or labelling.

Comparison of the Chemical Composition of Subchondral Trabecular Bone of Medial Femoral Condyle between with Advanced Osteoarthritis and without Osteoarthritis

BACKGROUND: The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur. METHODS: Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs. RESULTS: The maximum intensity of the phosphate peak was 2,376.51+/-954.6 for the non-OA group and 1,936.3+/-831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different (P=0.017). The maximum intensity of the amide I peak were 474.17+/-253.42 for the nonOA group and 261.91+/-205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups (P=0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity (P=0.027, P=0.014, P=0.012; P=0.038, P=0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different (P=0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens. CONCLUSIONS: The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.

Molecular imaging for theranostics in gastroenterology: one stone to kill two birds.

Molecular imaging in gastroenterology has become more feasible with recent advances in imaging technology, molecular genetics, and next-generation biochemistry, in addition to advances in endoscopic imaging techniques including magnified high-resolution endoscopy, narrow band imaging or autofluorescence imaging, flexible spectral imaging color enhancement, and confocal laser endomicroscopy. These developments have the potential to serve as "red flag" techniques enabling the earlier and accurate detection of mucosal abnormalities (such as precancerous lesions) beyond biomarkers, virtual histology of detected lesions, and molecular targeted therapy-the strategy of "one stone to kill two or three birds"; however, more effort should be done to be "blue ocean" benefit. This review deals with the introduction of Raman spectroscopy endoscopy, imaging mass spectroscopy, and nanomolecule development for theranostics. Imaging of molecular pathological changes in cells/tissues/organs might open the "royal road" to either convincing diagnosis of diseases that otherwise would only be detected in the advanced stages or novel therapeutic methods targeted to personalized medicine.

Molecular Imaging for Theranostics in Gastroenterology: One Stone to Kill Two Birds

Molecular imaging in gastroenterology has become more feasible with recent advances in imaging technology, molecular genetics, and next-generation biochemistry, in addition to advances in endoscopic imaging techniques including magnified high-resolution endoscopy, narrow band imaging or autofluorescence imaging, flexible spectral imaging color enhancement, and confocal laser endomicroscopy. These developments have the potential to serve as "red flag" techniques enabling the earlier and accurate detection of mucosal abnormalities (such as precancerous lesions) beyond biomarkers, virtual histology of detected lesions, and molecular targeted therapy-the strategy of "one stone to kill two or three birds"; however, more effort should be done to be "blue ocean" benefit. This review deals with the introduction of Raman spectroscopy endoscopy, imaging mass spectroscopy, and nanomolecule development for theranostics. Imaging of molecular pathological changes in cells/tissues/organs might open the "royal road" to either convincing diagnosis of diseases that otherwise would only be detected in the advanced stages or novel therapeutic methods targeted to personalized medicine.