Longer withdrawal time is not associated with increased patient discomfort in colonoscopy: a retrospective observational study

Kenichiro Majima,Yosuke Muraki 대한대장항문학회 2023 Annals of Coloproctolgy Vol.39 No.1

Purpose: Withdrawal time of sufficient length is a quality indicator for colonoscopies. Nonetheless, whether extending the withdrawal time contributes to patient discomfort remains unknown. This study aimed to clarify the relationship between colonoscopy withdrawal time and patient discomfort. Methods: A cohort of consecutive patients who underwent colonoscopy at a single institution from October 2018 to January 2020 was retrospectively analyzed. Initially, the relationship between the mean withdrawal time for each colonoscopist in no-finding examinations and polyp detection rate was investigated in 2,043 patients. Subsequently, the primary outcome of association between withdrawal time and patient discomfort, as determined by patient questionnaire, was assessed for each examination in 481 patients from the initial cohort. Results: The mean withdrawal time was strongly correlated with polyp detection rate (correlation coefficient, 0.72; P<0.001). In contrast, longer withdrawal time was not associated with increased discomfort; however, there was a weak inverse correlation between patient discomfort and longer withdrawal time (correlation coefficient, –0.25; P<0.001). Similarly, multiple regression analysis adjusted for confounding variables revealed that longer withdrawal time was not associated with increased patient discomfort (regression coefficient, –0.04 for each 1-minute increase in the length of withdrawal time; P=0.45). Conclusion: This study showed for the first time that longer withdrawal times did not result in increased discomfort, indicating that withdrawal time can be extended to sufficient length for optimal patient examination and polyp detection.

A New Criterion ` Effectiveness Factor ` for Pruning Hidden Units

Norihito Majima,Takashi Nagano,Akiko Watanabe,Akira Yoshimura 대한전자공학회 1994 ICONIP : International Conference On Neural Inform Vol.1 No.3

The role of interactions in open quantum systems and the second law of thermodynamics

Hiroki Majima,Akira Suzuki 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.3

In open quantum systems, it is dicult to know whether the system is in equilibrium or nonequilibrium. In order to investigate the role of interactions between the system and its environment in open quantum systems, we derive a formula which relates the Hamiltonian of the system to entropy. In this formula, these interactions inside the system and the entropy of the system are not connected to each other; only these interactions between the system and its environment are related to the entropy. Thus, this formula enables us to discriminate the types of interactions between the system and its environment; one type of interaction increases the entropy of the system, and the other type of interaction does not change the entropy of the system. We nd that a certain type of interaction between the system and its environment causes a nonequilibrium state of the system. The criteria for the types of interactions between the system and its environment are specically given by studying the entropy.

Feasibility of the Lilium α-200 portable ultrasound bladder scanner for accurate bladder volume measurement

Tsuyoshi Majima,Yumi Oota,Yoshihisa Matsukawa,Yasuhito Funahashi,Masashi Kato,Hiromitsu Mimata,Momokazu Gotoh 대한비뇨의학회 2020 Investigative and Clinical Urology Vol.61 No.6

Purpose: The aim of this study was to investigate whether data obtained from the Lilium α-200 (Lilium Otsuka Co., Ltd., Japan) correlated with conventional frequency-volume chart (FVC) and post-void residual urine volume (PVR) obtained by urethral catheterization. Materials and Methods: This was a prospective multicentre study. Patients hospitalized for the treatment of lower urinary tract symptoms were included. Patients were evaluated with conventional FVC and Lilium α-200 for 2 days. PVR was measured by urethral catherization after urination at the end of the 2 day evaluation period. Results: A total of 42 patients were enrolled in this study. Voided volume and PVR measured by Lilium α-200 were significantly correlated with voided volume obtained from conventional FVC and PVR measured by urethral catheterization, respectively. There was considerable measurement error in voided volume measured by Lilium α-200 (−21.0±102.0 mL). In contrast, the error between PVR measured by the Lilium α-200 and PVR obtained by urethral catheterization was 2.4±52.0 mL. Additionally, high body mass index, but not sex, benign prostate hyperplasia, time zone of measurement (daytime vs. nighttime), and examiners (a urologist versus other healthcare providers) were significantly associated with inaccurate results in voided volume. Conclusions: Voided volume and PVR measured by the Lilium α-200 were correlated with voided volume obtained from conventional FVC and PVR measured by urethral catheterization, although accuracy of the measurements was not high. The Lilium α-200 is a useful device to easily measure approximate bladder volume.

Conformational changes of non-B DNA

Choi, Jungkweon,Majima, Tetsuro Royal Society of Chemistry 2011 Chemical Society reviews Vol.40 No.12

<P>In contrast to B-DNA that has a right-handed double helical structure with Watson–Crick base pairing under the ordinary physiological conditions, repetitive DNA sequences under certain conditions have the potential to fold into non-B DNA structures such as hairpin, triplex, cruciform, left-handed Z-form, tetraplex, A-motif, <I>etc.</I> Since the non-B DNA-forming sequences induce the genetic instability and consequently can cause human diseases, the molecular mechanism for their genetic instability has been extensively investigated. On the contrary, non-B DNA can be widely used for application in biotechnology because many DNA breakage hotspots are mapped in or near the sequences that have the potential to adopt non-B DNA structures. In addition, they are regarded as a fascinating material for the nanotechnology using non-B DNAs because they do not produce any toxic byproducts and are robust enough for the repetitive working cycle. This being the case, an understanding on the mechanism and dynamics of their structural changes is important. In this <I>critical review</I>, we describe the latest studies on the conformational dynamics of non-B DNAs, with a focus on G-quadruplex, i-motif, Z-DNA, A-motif, hairpin and triplex (189 references).</P> <P>Graphic Abstract</P><P>In this review, we describe the latest studies on the conformational dynamics of non-B DNAs, with a focus on G-quadruplex, i-motif, Z-DNA, A-motif, hairpin and triplex. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cs15153c'> </P>

Single-molecule, single-particle fluorescence imaging of TiO₂-based photocatalytic reactions

Tachikawa, Takashi,Majima, Tetsuro Royal Society of Chemistry 2010 Chemical Society reviews Vol.39 No.12

<P>Nanostructured metal oxide semiconductors, such as TiO<SUB>2</SUB> and ZnO, have attracted great attention as the promising material for photovoltaic devices, photocatalysts for water splitting and environmental purification, sensors, batteries, <I>etc</I>. In this <I>critical review</I>, we have focused on the on-site observation of interfacial chemical reactions involving charge carriers and reactive oxygen species (ROS), such as singlet oxygen and the hydroxyl radical, generated by the photoexcitation of TiO<SUB>2</SUB> nanoparticles using single-molecule, single-particle fluorescence spectroscopy. Advanced fluorescence imaging techniques enable us to determine the location of the photocatalytically active sites that are closely related to the defects heterogeneously distributed on the surface. Consequently, this review provides a great opportunity to understand the temporal and spatial heterogeneities within an individual catalyst particle, allowing for the potential use of single-molecule, single-particle approaches in the analysis of photocatalytic reactions (189 references).</P> <P>Graphic Abstract</P><P>This critical review describes the progress in the single-molecule, single-particle fluorescence imaging techniques for exploring TiO<SUB>2</SUB> photocatalytic reactions. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b919698f'> </P>

Photoinduced Electron- and Energy-Transfer Processes in Supramolecules using Imide Compounds

Fujitsuka, Mamoru,Majima, Tetsuro Korean Society of Photoscience 2014 Rapid communication in photoscience Vol.3 No.1

We summarize recent studies on photoinduced electron- and energy-transfer processes of various supramolecules including imide group(s) as a component. Recently, imides have been employed in various functional molecular systems, because of their excellent photophysical and electron accepting properties. Our research group also employed imides in various supramolecular systems such as donor-acceptor dyads, quantum dots, DNA, and so on. First, we summarize fundamental properties of imides such as photophysical and electrochemical properties. Then, photoinduced processes of imides in the supramolecular systems are described to show their applicability in the various fields.

Hole and excess electron transfer dynamics in DNA

Fujitsuka, Mamoru,Majima, Tetsuro The Royal Society of Chemistry 2012 Physical chemistry chemical physics Vol.14 No.32

<P>Charge transfer in DNA attracts substantial attention from researchers in a wide group of fields such as bioscience, nanotechnology and physical chemistry. It is well known that both positive and negative charges, which are holes and excess electrons, respectively, contribute to the charge transfer in DNA. In the case of hole transfer in DNA, detailed mechanisms and dynamical parameters have been estimated by means of time-resolved spectroscopic methods and product analysis. On the other hand, detailed dynamics of excess electron transfer have not been established yet, although several aspects have been revealed by the continuous efforts of various research groups. In the present Perspective, studies on the charge transfer dynamics in DNA are summarized.</P> <P>Graphic Abstract</P><P>Kinetic studies of excess electron transfer in DNA are summarized as well as a brief summary of hole transfer. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp41576c'> </P>

Single-Molecule, Single-Particle Approaches for Exploring the Structure and Kinetics of Nanocatalysts

Tachikawa, Takashi,Majima, Tetsuro American Chemical Society 2012 Langmuir Vol.28 No.24

<P>In this Article, we focus on the in situ observation of photochemical reactions on individual nanoobjects of solid catalysts using single-molecule, single-particle fluorescence spectroscopy. The use of high-resolution imaging techniques with suitable fluorogenic probes enables us to determine the location of the catalytically active sites that are related to the structural heterogeneities on the surface of the solid catalyst and the temporal fluctuation of photochemical reactivity. Furthermore, we present the real-time observation of metastable gold nanoclusters in polymer matrices at the single-cluster level. This Article encourages readers to explore the nanoworld in terms of practical applications in many fields such as fundamental physics and chemistry.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2012/langd5.2012.28.issue-24/la300177h/production/images/medium/la-2012-00177h_0009.gif'></P>

대두 및 고구마 β-Amyiase 의 비교에 관한 연구

Mikami, Bunzo,Majima, Keiichi,Morita, Yuhei,김용휘,김준평 한국콩연구회 1988 韓國콩硏究會誌 Vol.5 No.1

대두 및 고구마로부터 얻은 β-amylase의 단백질 구조를 CD spectra, 항체반응, 화학적 절단을 통하여 비교하였다. 고구마 β-amylase는 4개의 동일한 subunit로 구성되어 있으며 대두 β-amylase는 subunit구조를 하고 있지 않았다. 또한 두 효소는 변성시킨 상태에서 SDS-gel전기영동, gel filtration한 결과 분자량은 동일하였다. 그리고 대두 및 고구마 β- amylase는 CD spectra 상 유사한 2차구조를 나타내고 있으나 방향족 측쇄가 상이함을 나타냈다. 한편 cyteine 잔기 및 mechionine 잔기의 화학적 절단한 결과 두 효소는 동일한 아미노산 배열을 나타냈다. 또한 면역학적인 방법에 의해서도 두 효소는 유사성이 인정되었다. 한편 대두 β-amylase에 대한 항체는 고구마 β-amylase의 활성을 억제 하였으나 밀, 보리, 무우 β-amylase에 대해서는 활성 억제가 나타나지 않았다.