癌診断支援のためのSIFT特徴量を用いた大腸拡大内視鏡画像の認識

平成20年度電気・情報関連学会中国支部第59回連合大会発表資料 ; 開催地:鳥取大学 ; 開催日:2008年10月25

The core mass function in the Orion Nebula Cluster region : What Determines the Final Stellar Masses?

Funding: European Research Council (ERC) via the ERC Synergy Grant ECOGAL (grant 855130) (R.S.K.).Applying dendrogram analysis to the CARMA-NRO C18O (J = 1–0) data having an angular resolution of ∼8'', we identified 692 dense cores in the Orion Nebula Cluster region. Using this core sample, we compare the core and initial stellar mass functions in the same area to quantify the step from cores to stars. About 22% of the identified cores are gravitationally bound. The derived core mass function (CMF) for starless cores has a slope similar to Salpeter's stellar initial mass function (IMF) for the mass range above 1 M⊙, consistent with previous studies. Our CMF has a peak at a subsolar mass of ∼0.1 M⊙, which is comparable to the peak mass of the IMF derived in the same area. We also find that the current star formation rate is consistent with the picture in which stars are born only from self-gravitating starless cores. However, the cores must gain additional gas from the surroundings to reproduce the current IMF (e.g., its slope and peak mass), because the core mass cannot be accreted onto the star with 100% efficiency. Thus, the mass accretion from the surroundings may play a crucial role in determining the final stellar masses of stars.Peer reviewe

CARMA-NRO Orion survey: Unbiased survey of dense cores and core mass functions in Orion A

The mass distribution of dense cores is a potential key to understanding the process of star formation. Applying dendrogram analysis to the CARMA-NRO Orion C18O (J = 1–0) data, we identify 2342 dense cores, about 22% of which have virial ratios smaller than 2 and can be classified as gravitationally bound cores. The derived core mass function (CMF) for bound starless cores that are not associate with protostars has a slope similar to Salpeter's initial mass function (IMF) for the mass range above 1 M⊙, with a peak at ∼0.1 M⊙. We divide the cloud into four parts based on decl., OMC-1/2/3, OMC-4/5, L1641N/V380 Ori, and L1641C, and derive the CMFs in these regions. We find that starless cores with masses greater than 10 M⊙ exist only in OMC-1/2/3, whereas the CMFs in OMC-4/5, L1641N, and L1641C are truncated at around 5–10 M⊙. From the number ratio of bound starless cores and Class II objects in each subregion, the lifetime of bound starless cores is estimated to be 5–30 freefall times, consistent with previous studies for other regions. In addition, we discuss core growth by mass accretion from the surrounding cloud material to explain the coincidence of peak masses between IMFs and CMFs. The mass accretion rate required for doubling the core mass within a core lifetime is larger than that of Bondi–Hoyle accretion by a factor of order 2. This implies that more dynamical accretion processes are required to grow cores.This work was supported in part by The Graduate University for Advanced Studies, SOKENDAI, and JSPS KAKENHI grant No. 22J13587. Data analysis was carried out on the Multi-wavelength Data Analysis System operated by the Astronomy Data Center (ADC), National Astronomical Observatory of Japan. This work was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA (80NM0018D0004). N.S. acknowledges support from the project GENESIS (ANR-16-CE92-0035-01/DFG1591/2-1), the project FEEDBACK (DLR, 50 OR 1916), and the SFB 956 (DFG). P.S. was partially supported by a Grant-in-Aid for Scientific Research (KAKENHI Number 18H01259) of the Japan Society for the Promotion of Science (JSPS). P.P. acknowledges support by the grant PID2020-115892GBI00 funded by MCIN/AEI/10.13039/501100011033.Peer reviewe

Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy

Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compared prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. Twenty sites in the esophagus and 40 sites in the stomach were examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan), was used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei were visualized. In 9 of the 10 normal esophageal mucosa, cell membranes were visualized, and in 5 of the 10 esophageal cancers, cell membranes were visualized. In all normal gastric mucosa, nuclei and cell membranes were not visualized, but in 10 of the 20 gastric cancers, nuclei were visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy

Outcome of patients who have undergone total enteroscopy for obscure gastrointestinal bleeding

AIM: To assess the diagnostic success and outcome among patients with obscure gastrointestinal bleeding who underwent total enteroscopy with double-balloon endoscopy

Quantitative analysis and development of a computer-aided system for identification of regular pit patterns of colorectal lesions

Background: Because pit pattern classification of colorectal lesions is clinically useful in determining treatment options for colorectal tumors but requires extensive training, we developed a computerized system to automatically quantify and thus classify pit patterns depicted on magnifying endoscopy images. Objective: To evaluate the utility and limitations of our automated pit pattern classification system. Design: Retrospective study. Setting: Department of endoscopy at a university hospital. Main Outcome Measurements: Performance of our automated computer-based system for classification of pit patterns on magnifying endoscopic images in comparison to classification by diagnosis of the 134 regular pit pattern images by an endoscopist. Results: For type I and II pit patterns, the results of discriminant analysis were in complete agreement with the endoscopic diagnoses. Type IIIL was diagnosed in 29 of 30 cases (96.7%) and type IV was diagnosed in 1 case. Twenty-nine of 30 cases (96.7%) were diagnosed as type IV pit pattern. The overall accuracy of our computerized recognition system was 132 of 134 (98.5%). Conclusions: Our system is best characterized as semiautomated but is a step toward the development of a fully automated system to assist in the diagnosis of colorectal lesions based on classification of pit patterns

Analysis of Cardiopulmonary Stress during Endoscopy: Is Unsedated Transnasal Esophagogastroduodenoscopy Appropriate for Elderly Patients?

BACKGROUND: Transnasal esophagogastroduodenoscopy (EGD) without sedation has been reported to be safe and tolerable. It has recently been used widely in Japan for the detection of upper gastrointestinal disease. Alternatively, transoral examination using a thin endoscope has also been reported to be highly tolerable