BACKGROUND Cancer detection is a global research focus,and novel,rapid,and label-free techniques are being developed for routine clinical practice.This has led to the development of new tools and techniques from the b...BACKGROUND Cancer detection is a global research focus,and novel,rapid,and label-free techniques are being developed for routine clinical practice.This has led to the development of new tools and techniques from the bench side to routine clinical practice.In this study,we present a method that uses Raman spectroscopy(RS)to detect cancer in unstained formalin-fixed,resected specimens of the esophagus and stomach.Our method can record a clear Raman-scattered light spectrum in these specimens,confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue.AIM To evaluate the use of Raman-scattered light spectrum for detecting endoscopically resected specimens of esophageal squamous cell carcinoma(SCC)and gastric adenocarcinoma(AC).METHODS We created a Raman device that is suitable for observing living tissues,and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues.We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility,ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions.Furthermore,a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed.RESULTS We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens.After data capture,the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations.Based on data analysis of molecular-level substrates,we established cut-off values for the diagnosis of esophageal SCC and gastric AC.By analyzing specific Raman shifts,we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses.CONCLUSION Our technique provides qualitative information for real-time morphological diagnosis.However,further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation.展开更多
AIM To analyse the long-term prognostic impact of circulating tumour cells(CTCs) in gastric cancer patients who underwent surgery. METHODS A 7.5-m L peripheral vein blood sample was obtained from each patient with tre...AIM To analyse the long-term prognostic impact of circulating tumour cells(CTCs) in gastric cancer patients who underwent surgery. METHODS A 7.5-m L peripheral vein blood sample was obtained from each patient with treatment-negative gastric adenocarcinoma before surgery. OBP-401, a telomerasespecific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein gene, was used to label CTCs. Correlations between the number of CTCs and clinical end points were evaluated. RESULTS The median follow-up period of the surviving patients with gastric cancer was 60 mo. The CTC number tended to increase concomitantly with disease progression. The overall survival of patients with more than five CTCs in 7.5-m L of peripheral blood was lower than that of patients with five or less CTCs, although the difference was not significant(P = 0.183). A significant difference in relapse-free survival was found between patients with more than five and those with five or less CTCs(P = 0.034).CONCLUSION A lower number of CTCs was correlated with higher relapse-free survival rates in patients. Detection of CTCs using OBP-401 may be useful for predicting prognosis in gastric cancer.展开更多
BACKGROUND Colorectal cancer(CRC) is an important disease worldwide, accounting for the second highest number of cancer-related deaths and the third highest number of new cancer cases. The blood test is a simple and m...BACKGROUND Colorectal cancer(CRC) is an important disease worldwide, accounting for the second highest number of cancer-related deaths and the third highest number of new cancer cases. The blood test is a simple and minimally invasive diagnostic test. However, there is currently no blood test that can accurately diagnose CRC.AIM To develop a comprehensive, spontaneous, minimally invasive, label-free, bloodbased CRC screening technique based on Raman spectroscopy.METHODS We used Raman spectra recorded using 184 serum samples obtained from patients undergoing colonoscopies. Patients with malignant tumor histories as well as those with cancers in organs other than the large intestine were excluded. Consequently, the specific diseases of 184 patients were CRC(12), rectal neuroendocrine tumor(2), colorectal adenoma(68), colorectal hyperplastic polyp(18), and others(84). We used the 1064-nm wavelength laser for excitation. The power of the laser was set to 200 mW.RESULTS Use of the recorded Raman spectra as training data allowed the construction of a boosted tree CRC prediction model based on machine learning. Therefore, the generalized R^2 values for CRC, adenomas, hyperplastic polyps, and neuroendocrine tumors were 0.9982, 0.9630, 0.9962, and 0.9986, respectively.CONCLUSION For machine learning using Raman spectral data, a highly accurate CRC prediction model with a high R^2 value was constructed. We are currently planning studies to demonstrate the accuracy of this model with a large amount of additional data.展开更多
Experiments are performed to develop a pulsed corona discharge system for the conversion of methane to hydrogen at atmospheric pressure (≌760 Tort) without using a catalyst. The corona discharge was energized by 10-...Experiments are performed to develop a pulsed corona discharge system for the conversion of methane to hydrogen at atmospheric pressure (≌760 Tort) without using a catalyst. The corona discharge was energized by 10-12 μs wide voltage pulses (≤7 kV) at a repetition rate of about 1.0-1.5 kHz. The residual gases were characterized by mass spectrometry. The conversion of methane is as high as 50.8%producing the 70% yield of hydrogen. The influences of argon on the discharge of methane were studied.This result could be useful for the mass production of hydrogen in both academic and industrial point of view.展开更多
AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS W...AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm^(-1) and 782 cm^(-1), are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm^(-1)/620 cm^(-1), 782 cm^(-1)/756 cm^(-1), 782 cm^(-1)/1250 cm^(-1), and 782 cm^(-1)/1263 cm^(-1) in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.CONCLUSION The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.展开更多
In the present paper, the influence of carbon nanofiber on interlaminar fracture toughness of CFRP investigated using MMB(Mixed Mode Bending) tests. Vapor grown carbon fiber VGCF and VGCF-S, and multi-walled carbon na...In the present paper, the influence of carbon nanofiber on interlaminar fracture toughness of CFRP investigated using MMB(Mixed Mode Bending) tests. Vapor grown carbon fiber VGCF and VGCF-S, and multi-walled carbon nanotube MWNT-7 has been employed for the toughener of the interlayer on the CFRP laminates. In order to evaluate the fracture toughness and mixed mode ratio of it, double cantilever beam (DCB) tests, end notched fracture (ENF) tests and mixed mode bending (MMB) tests have been carried out. Boundary element analysis was applied to the CFRP model to compute the interlaminar fracture toughness, where extrapolation method was used to determine the fracture toughness and mixed mode ratio. The interlaminar fracture toughness and mixed mode ratio can be extrapolated by stress distribution in the vicinity of the crack tip of the CFRP laminate. It was found that the interlaminar fracture toughness of the CFRP laminates was improved inserting the interlayer made by carbon nanofiber especially in the region where shear mode deformation is dominant.展开更多
基金Supported by MEXT KAKENHI,JP17K09022 and JP20K07643.
文摘BACKGROUND Cancer detection is a global research focus,and novel,rapid,and label-free techniques are being developed for routine clinical practice.This has led to the development of new tools and techniques from the bench side to routine clinical practice.In this study,we present a method that uses Raman spectroscopy(RS)to detect cancer in unstained formalin-fixed,resected specimens of the esophagus and stomach.Our method can record a clear Raman-scattered light spectrum in these specimens,confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue.AIM To evaluate the use of Raman-scattered light spectrum for detecting endoscopically resected specimens of esophageal squamous cell carcinoma(SCC)and gastric adenocarcinoma(AC).METHODS We created a Raman device that is suitable for observing living tissues,and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues.We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility,ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions.Furthermore,a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed.RESULTS We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens.After data capture,the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations.Based on data analysis of molecular-level substrates,we established cut-off values for the diagnosis of esophageal SCC and gastric AC.By analyzing specific Raman shifts,we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses.CONCLUSION Our technique provides qualitative information for real-time morphological diagnosis.However,further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation.
基金Supported by a Japan Society for the Promotion of Science(JSPS)KAKENHI Grant-in-Aid for Challenging Exploratory Research(in part)No.23659308JSPS KAKENHI Grantin-Aid for Scientific Research,No.26460688
文摘AIM To analyse the long-term prognostic impact of circulating tumour cells(CTCs) in gastric cancer patients who underwent surgery. METHODS A 7.5-m L peripheral vein blood sample was obtained from each patient with treatment-negative gastric adenocarcinoma before surgery. OBP-401, a telomerasespecific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein gene, was used to label CTCs. Correlations between the number of CTCs and clinical end points were evaluated. RESULTS The median follow-up period of the surviving patients with gastric cancer was 60 mo. The CTC number tended to increase concomitantly with disease progression. The overall survival of patients with more than five CTCs in 7.5-m L of peripheral blood was lower than that of patients with five or less CTCs, although the difference was not significant(P = 0.183). A significant difference in relapse-free survival was found between patients with more than five and those with five or less CTCs(P = 0.034).CONCLUSION A lower number of CTCs was correlated with higher relapse-free survival rates in patients. Detection of CTCs using OBP-401 may be useful for predicting prognosis in gastric cancer.
基金the Japanese Society for the Promotion of Science (JSPS),based on the JSPS KAKENHI Grants-in-Aid for Scientific Research (C),No. JP17K09022。
文摘BACKGROUND Colorectal cancer(CRC) is an important disease worldwide, accounting for the second highest number of cancer-related deaths and the third highest number of new cancer cases. The blood test is a simple and minimally invasive diagnostic test. However, there is currently no blood test that can accurately diagnose CRC.AIM To develop a comprehensive, spontaneous, minimally invasive, label-free, bloodbased CRC screening technique based on Raman spectroscopy.METHODS We used Raman spectra recorded using 184 serum samples obtained from patients undergoing colonoscopies. Patients with malignant tumor histories as well as those with cancers in organs other than the large intestine were excluded. Consequently, the specific diseases of 184 patients were CRC(12), rectal neuroendocrine tumor(2), colorectal adenoma(68), colorectal hyperplastic polyp(18), and others(84). We used the 1064-nm wavelength laser for excitation. The power of the laser was set to 200 mW.RESULTS Use of the recorded Raman spectra as training data allowed the construction of a boosted tree CRC prediction model based on machine learning. Therefore, the generalized R^2 values for CRC, adenomas, hyperplastic polyps, and neuroendocrine tumors were 0.9982, 0.9630, 0.9962, and 0.9986, respectively.CONCLUSION For machine learning using Raman spectral data, a highly accurate CRC prediction model with a high R^2 value was constructed. We are currently planning studies to demonstrate the accuracy of this model with a large amount of additional data.
文摘Experiments are performed to develop a pulsed corona discharge system for the conversion of methane to hydrogen at atmospheric pressure (≌760 Tort) without using a catalyst. The corona discharge was energized by 10-12 μs wide voltage pulses (≤7 kV) at a repetition rate of about 1.0-1.5 kHz. The residual gases were characterized by mass spectrometry. The conversion of methane is as high as 50.8%producing the 70% yield of hydrogen. The influences of argon on the discharge of methane were studied.This result could be useful for the mass production of hydrogen in both academic and industrial point of view.
基金Supported by the Japan Society for the Promotion of Science(JSPS)through two JSPS KAKENHI Grants-in-Aid for Scientific Research(C)No.JP26460688 and JP17K09022
文摘AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm^(-1) and 782 cm^(-1), are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm^(-1)/620 cm^(-1), 782 cm^(-1)/756 cm^(-1), 782 cm^(-1)/1250 cm^(-1), and 782 cm^(-1)/1263 cm^(-1) in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.CONCLUSION The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens.
基金supported by the Program for Fostering Regional Innovation in Nagano, granted by MEXT, Japan
文摘In the present paper, the influence of carbon nanofiber on interlaminar fracture toughness of CFRP investigated using MMB(Mixed Mode Bending) tests. Vapor grown carbon fiber VGCF and VGCF-S, and multi-walled carbon nanotube MWNT-7 has been employed for the toughener of the interlayer on the CFRP laminates. In order to evaluate the fracture toughness and mixed mode ratio of it, double cantilever beam (DCB) tests, end notched fracture (ENF) tests and mixed mode bending (MMB) tests have been carried out. Boundary element analysis was applied to the CFRP model to compute the interlaminar fracture toughness, where extrapolation method was used to determine the fracture toughness and mixed mode ratio. The interlaminar fracture toughness and mixed mode ratio can be extrapolated by stress distribution in the vicinity of the crack tip of the CFRP laminate. It was found that the interlaminar fracture toughness of the CFRP laminates was improved inserting the interlayer made by carbon nanofiber especially in the region where shear mode deformation is dominant.
