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The conformational equilibria of 1,4-dioxane in organic solvents and aqueous solution have been investigated by Raman spectroscopy with the aid of density functional theory calculations. The proportions of the conformers of 1,4-dioxane in the liquid phase has been a controversial issue. We determined that the proportions of the 2,5-twisted-boat and 1,4-twisted-boat conformers are 12% and 9%, respectively. We also determined the conformational thermodynamics in the pure liquid, methanol, and water. Finally, we demonstrated that the hydration structure outside the first shell plays a crucial role in the conformational thermodynamics in aqueous solution. [ABSTRACT FROM AUTHOR]

The origin of high solubility ofpoly(oxyethylene) in water hasbeen an open question. Although it is thought that the high solubilityof poly(oxyethylene) arises from an increase of the trans–gauche–trans(tgt) conformer in water, the relationship between the increaseof the tgtconformer and the solubility is unclear.In this study, we have investigated the conformational equilibriaof 1,2-dimethoxyethane, which is a model molecule for poly(oxyethylene),by using Raman spectroscopy, and determined the change in the populationand the free energy of each conformer with the aid of density functionaltheory calculations. The free energy of transfer of the tgtconformer from the pure liquid to the water phase is −6.1± 0.2 kJ mol–1. Furthermore, the fraction ofthe tgtconformer increases from 0.37 to 0.78. Thus,the net contribution of the tgtconformer is −4.8± 0.2 kJ mol–1, which is 79% of the total freeenergy of transfer (−6.07 kJ mol–1). Thisdemonstrates that the high solubility of 1,2-dimethoxyethane originatesfrom the lowest free energy and the highest fraction of the tgtconformer in water. We also successfully explain thethermodynamic mechanism of the low solubility of dimethoxymethane,which is the model molecule for poly(oxymethylene). [ABSTRACT FROM AUTHOR]

This paper studies closures of fractal sets observed in nonlinear dynamical systems excited stochastically by switched inputs. The Duffing oscillator and the forced dumped pendulum are analyzed as examples. The dynamics of the system is characterized by a fractal set in the phase space. We can numerically construct a closure that encloses the fractal set. Furthermore, it is shown that the closure is a limit cycle attractor of a dynamical system defined by the switching manifold. [ABSTRACT FROM AUTHOR]

Fractals and closures of two-dimensional linear dynamical systems excited by temporal inputs are investigated. The continuous dynamics defined by the set of vector fields in the cylindrical phase space is reduced to the discrete dynamics defined by the set of iterated functions on the Poincaé section. When all iterated functions are contractions, it has already been shown theoretically that a trajectory in the cylindrical phase space converges into an attractive invariant set with a fractal-like structure. Calculating analytically the Lipschitz constants of iterated functions, we show that, under some conditions, noncontractions often appear. However, we numerically show that, even for noncontractions, an attractive invariant set with a fractal-like structure exists. By introducing the interpolating system, we can also show that the set of trajectories in the cylindrical phase space is enclosed by the tube structure whose initial set is the closure of the fractal set on the Poincaé section. [ABSTRACT FROM AUTHOR]

The ABC method is a classification method used for stratifying the risk of gastric cancer. However, whether the ABC method should be performed only once or multiple times throughout an individual's lifetime remains unclear. Therefore, this study aimed to analyze whether performing ABC screening twice in a lifetime is useful. We retrospectively analyzed the data of individuals who participated in health checkups in 2010 and 2015. We collected data on patient characteristics, pepsinogen levels, anti-Helicobacter pylori antibody titers, and the presence of gastric cancer. Overall, 7129 participants without a history of H. pylori eradication were included in this study. The participants' average age in 2010 was 48.4 ± 8.3 years, and 58.1% were male. In addition, 11 and 20 cases of new H. pylori infection (0.15%) and spontaneous eradication (0.28%), respectively, were recorded. No significant difference was found in the incidence of gastric cancer between participants who underwent the ABC method once and those who underwent it twice (Group A: 0.16% vs. 0.16%; Group B: 0.47% vs. 0.39%; and Group C + D: 1.97% vs. 1.82%). Therefore, performing the ABC method twice, 5 years apart, does not significantly improve gastric cancer risk stratification. [ABSTRACT FROM AUTHOR]

A non-invasive method to evaluate the fibrosis stage and the risk stratification of non-alcoholic fatty liver disease (NAFLD) is required. A total of 416,066 generally healthy subjects who underwent health check-ups between 1990 and 2019 were investigated. Fatty liver prevalence greatly increased from the 1990s (21.9%) to the 2000s (37.1%) but showed no considerable change between 2001–2010 (39.2%) and 2011–2019 (35.5%). During the 30 years, the rate of high FIB-4 index (≥2.67) and mean body mass index (BMI) did not markedly change. Fatty liver was significantly associated with BMI, but not with alcohol intake or FIB-4 index. Cox regression analyses for development of chronic hepatitis or liver cirrhosis identified that the risk of developing chronic hepatitis and liver cirrhosis was higher in subjects without fatty liver than in those with it (hazard ratio [HR]=0.09; 95% confidence interval [CI], 0.03–0.22, p <0.001 and HR=0.04; 95% CI, 0.01–0.26, p =0.001, respectively), and much larger in subjects with a high FIB-4 index (≥ 2.67) than in those without it (HR=78.6; 95% CI, 29.0–213.1, p <0.001 and HR=5950.7; 95% CI,761.7–46,491.4, p <0.001, respectively). Adjusted survival curves for Cox proportional hazards regression further reinforced these results. In conclusion, the FIB-4 index is a useful indicator of chronic hepatitis and liver cirrhosis development in the general population. [ABSTRACT FROM AUTHOR]

Our study aimed to evaluate the relationship between visceral obesity and its associated factors, especially sleep duration in East Asia. We conducted univariate and multivariate analyses using the data of 2538 participants (mean age 56.4 ± 10.8 years) who underwent medical checkups and computed tomography of the abdomen to calculate the visceral fat area from 2008 to 2020. We additionally performed logistic regression analyses using each sleep-duration group (< 5, 5–6, 6–7, 7–8, and ≥ 8 h) and their respective propensity scores as covariates. According to the criteria of visceral obesity(a visceral fat area ≥ 100 cm2), 1147 of 1918 men (59.8%) and 131 of 620 women (21.1%) had visceral obesity. In multivariate analyses, visceral obesity was significantly associated with age, body mass index and triglyceride in both genders, high-density lipoproteins, uric acid levels, and daily alcohol consumption in men; and glycated hemoglobin (HbA1c) in women. In both multivariate and propensity score matching analyses, sleep duration of > 8 h and visceral obestiy showed a positive association in men but a negative association in women with statistical significance. In conclusion, our large-scale cross-sectional study in East Asia identified various gender-specific factors associated with visceral obesity including the long sleep duration. [ABSTRACT FROM AUTHOR]

Introduction:Helicobacter pylori eradication is expected to significantly change the prevalence of Barrett's esophagus (BE). However, few reports on this relationship exist. We analyzed the risk factors of BE using the current consensus on length of BE considering H. pylori infection status. Methods: We analyzed 10,122 individuals (5,962 men; mean age = 52.9 ± 9.9 years) who had undergone esophagogastroduodenoscopy as part of a medical checkup. Correlations among factors including H. pylori infectious status, endoscopic findings, and BE ≥1 cm were analyzed. Results: Prevalence of BE, long-segment BE, and esophageal adenocarcinoma was 22.5%, 0.014%, and 0%, respectively. Logistic regression analysis showed that the risk factors for BE were hiatal hernia (odds ratio [OR]: 2.89 [2.59–3.24]), female sex (OR: 0.52 [0.46–0.59]), social drinking (OR:0.77 [0.68–0.87]), H. pylori eradication therapy (OR: 1.34 [1.19–1.51]), proton pump inhibitor (PPI) use (OR: 1.52 [1.18–1.96]), bile reflux (OR: 1.18 [1.04–1.33]), age ≥50 years (OR: 1.13 [1.02–1.26]), and nonsteroidal anti-inflammatory drug (NSAID) use (OR: 1.29 [1.02–1.62]). Although reflux esophagitis (RE) was more common in H. pylori-negative patients (17.2%) than in those after H. pylori eradication therapy (11.8%, p < 0.00001), the latter was correlated with BE, disputing RE as a strong risk factor for BE. Therefore, we conducted a subgroup analysis; most of the risk factors except for PPI use (p = 0.75), H2-receptor antagonist use (p = 0.078), and atrophic gastritis absence (p = 0.72) were positively correlated with BE after H. pylori eradication therapy compared with H. pylori-negative status. Conclusions:H. pylori eradication, bile reflux, PPI use, and NSAID use were risk factors for BE along with hiatal hernia, male sex, and older age. [ABSTRACT FROM AUTHOR]

The increasing usage of proton pump inhibitors (PPIs) has been reported worldwide, but information on PPI use in East Asia is inadequate. This study aimed to examine the trends in PPI use in Japan, along with the changes in histamine H2 receptor antagonist (H2RA) use, disease rate of reflux esophagitis, and the prevalence of upper gastrointestinal symptoms. We analyzed 217,712 healthy subjects (127,607 men and 90,105 women; 51.4 ± 9.7 years old) participating in the health check program from 2010 to 2019. Various upper gastrointestinal symptoms were evaluated using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG) questionnaire. Reflux esophagitis was diagnosed by esophageal erosion using the Los Angeles classification grades A, B, C, and D. From 2010 to 2019, the percentage of PPI users increased markedly from approximately 1.8% to 5.3%, whereas that of H2RA users decreased gradually from approximately 2.5% to 1.9%. The use of all classical types of PPIs (omeprazole, lansoprazole, rabeprazole, and esomerazole) and a new type of PPI, a potassium-competitive acid blocker (vonoprazan), greatly increased during the 10 years. An upward trend in the prevalence of reflux esophagitis was observed from 2010 to 2015, but not from 2016 to 2019, indicating that the monotonic rising prevalence of reflux disease stopped in the middle of the 2010s in Japan. In contrast, various upper gastrointestinal symptoms significantly improved between 2010 and 2019. All 12 FSSG symptoms of PPI users were significantly worse than those of non-PPI users, suggesting that PPIs still cannot completely control upper gastrointestinal symptoms. In conclusion, this study revealed a significant increase in PPI use and a slight decrease in H2RA use from 2010 to 2019. Despite a plateau in the prevalence of reflux esophagitis and considerable improvement in various upper gastrointestinal symptoms, PPI use has continued to increase in Japan. [ABSTRACT FROM AUTHOR]

Background: The numbers of Helicobacter pylori (HP)-infected individuals and deaths due to gastric cancer are decreasing in Japan. We aimed to determine whether the serological test for chronic gastritis (the ABC method) is still useful for gastric cancer risk stratification in the 2010s and to analyze risk factors for developing gastric cancer in Japan. Methods: In this prospective study, we monitored 20773 individuals for the incidence of gastric cancer from 2010 to 2019. The relationships between blood sampling results, physical examination, and lifestyle in 2010 and the cumulative incidence of gastric cancer were analyzed. Results: A total of 19343 participants who met the study criteria were analyzed. Overall, 0.08% of participants in group A (9/11717), 0.63% in group B (28/4452), 2.05% in group C (43/2098), 1.52% in group D (1/66), and 0.30% in group E (3/1010) developed gastric cancer. Cox hazard analysis showed that age ≥ 50 years; groups B, C, and D according to the ABC method; and current smoking habits were independent risk factors for gastric cancer. The hazard ratios (HRs) of the incidence of gastric cancer were 6.7 in group B and 21.7 in groups C and D, while the HRs of group E was 2.8, which was not significantly different from that of group A. The incidence of gastric cancer was not statistically significantly different between those with and without successful HP eradication in groups B, C, and D during follow-up. Conclusions: The ABC method was still useful for gastric cancer risk stratification in the 2010s. [ABSTRACT FROM AUTHOR]

Background: Several previous studies have suggested that Helicobacter pylori (H. pylori) infection affects the serum lipid profile. However, it remains controversial and the mechanism has not been elucidated. The purpose of this study is to use an epidemiological perspective to evaluate the association between H. pylori infection and the serum lipid profile. Methods: Multivariate analysis was performed using the data of serum lipid profile, infection status of H. pylori, fitness/lifestyle habits, and various subjects' characteristics which were derived from the 15,679 generally healthy individuals in Japan. The average treatment effects (ATEs) of H. pylori infection on the serum lipid profile were estimated using augmented inverse probability weighting (AIPW). A meta-analysis was also performed using the 27 studies worldwide in which the status of H. pylori infection and at least one serum examination value (high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), or triglyceride (TG)) were described. Results: The ATEs determined with AIPW showed that H. pylori infection has significant positive effects on LDL-C and TC (ATE (95% confidence interval [95%CI]) = 3.4 (2.36–4.49) and 1.7 (0.58–2.88), respectively) but has significant negative effects on HDL-C and TG (ATE (95%CI) = −1.2 (−1.74 to −0.72) and −3.5 (−5.92 to −1.06), respectively). The meta-analysis to estimate the association between H. pylori infection and the serum lipid profile revealed that H. pylori infection is positively associated with LDL-C, TC, and TG (standardized mean difference [SMD] (95%CI) = 0.11 (0.09–0.12), 0.09 (0.07–0.10) and 0.06 (0.05–0.08), respectively) and negatively associated with HDL-C (SMD = −0.13 (−0.14 to −0.12)). Conclusion: Both our multivariate analyses and meta-analysis showed that H. pylori infection significantly affects the serum lipid profile, which might lead to various dyslipidemia-induced severe diseases like coronary thrombosis or cerebral infarction. [ABSTRACT FROM AUTHOR]

Background: Upper gastrointestinal endoscopy (UGI-ES) and double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) are two major image-based methods to diagnose atrophic gastritis, which is mostly induced by Helicobacter pylori infection. However, there have been few studies directly comparing them. Methods: Atrophic gastritis was evaluated using the data of 962 healthy subjects who underwent UGI-ES and UGI-XR within 1 year. Results and conclusion: Based on UGI-ES and UGI-XR, 602 subjects did not have atrophic gastritis and 254 subjects did have it. Considering UGI-ES-based atrophic gastritis as the standard, sensitivity and specificity of UGI-XR-based atrophic gastritis were 92.0 % (254/276) and 92.8 % (602/649), respectively. The seven-grade Kimura-Takemoto classification of UGI-ES-based atrophic gastritis showed a strong and significant association with the four-grade UGI-XR-based atrophic gastritis. Sensitivity and specificity of serum anti- Helicobacter pylori IgG to detect UGI-ES/UGI-XR-based atrophic gastritis were 89.4 % (227/254) and 99.8 % (601/602), indicating that atrophic gastritis can be overlooked according to serum anti- Helicobacter pylori IgG alone. [ABSTRACT FROM AUTHOR]

The Shannon information entropy theory is used to explain the recently proposed isobaric yield ratio difference (IBD) probe which aims to determine the nuclear symmetry energy. Theoretically, the difference between the Shannon uncertainties carried by isobars in two different reactions ( Δ I n 21 ), is found to be equivalent to the difference between the chemical potentials of protons and neutrons of the reactions [the IBD probe, IB- Δ ( β μ ) 21 , with β the reverse temperature]. From the viewpoints of Shannon information entropy, the physical meaning of the above chemical potential difference is interpreted by Δ I n 21 as denoting the nuclear symmetry energy or density difference between neutrons and protons in reactions more concisely than from the statistical ablation–abrasion model. [ABSTRACT FROM AUTHOR]

Background: Gastric atrophy is a major risk factor for non-cardiac gastric cancer. Serum pepsinogen status could identify people at high-risk for gastric cancer development during our previous cohort study. However, lifestyle-related factors may additionally affect this risk. Materials and methods: A total of 6983 Japanese were followed up by annual endoscopy in the previous study, and 43 cases of gastric cancer including two cardiac cancers developed. In most subjects, the body length and weight were measured and a questionnaire was applied to gather information regarding life habits. The risk of non-cardiac gastric cancer development during surveillance was re-analyzed based on serum pepsinogen, sex, age, body mass index (BMI), alcohol, and smoking habit. Results: A total of 6158 subjects with 37 non-cardiac gastric cancer development (male/female = 4259/1899, mean age = 49.0, mean follow-up period = 4.79 years) were entered into analysis. In a multivariate analysis, old age (by 10 years; (odds ratio) OR, 2.8; p < .001), alcohol (weekly; OR, 2.4; p = .03), smoking (current; OR, 5.6; p = .006 and past; OR, 3.9; p = .04), and pepsinogen status (“atrophic”; OR, 6.2; p < .001) were independent risk factors, whereas BMI was not. The annual incidence of gastric cancer was 1.2% in the older subjects aged ≥ 60 years with “atrophic” pepsinogen status. Moreover, it was as high as 2.9% when they had both alcohol and current smoking habits. Conclusions: Old age, alcohol, and smoking habits additionally promoted the risk for gastric cancer in subjects with gastric atrophy. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Postcholecystectomy patients show moderate risk of colorectal cancer. However, few studies have investigated the relationship between cholelithiasis and colorectal adenoma. We examined this possibility through a combination of colonoscopy and ultrasonography in asymptomatic Japanese. METHODS: We reviewed a subgroup of subjects drawn from a prospective annual colonoscopy screening survey. Subjects who underwent both ultrasonography and colonoscopy, and completed a questionnaire regarding lifestyle habits were entered. We investigated whether subjects with cholelithiasis or a previous cholecystectomy showed an increased risk of colorectal adenoma, as compared with subjects with normal gallbladders. RESULTS: Data of 4,458 subjects (men 3,053, women 1,405, mean age ± SD 46.1 ± 8.62 yr) were analyzed. Cholelithiasis was detected in 206 subjects, 4,189 subjects had normal gallbladders, and 63 subjects had cholecystectomies. The prevalence of colorectal adenoma was 29.6% (61/206) in subjects with cholelithiasis, which was significantly higher when compared with normal subjects, with a prevalence of 17.7% (741/4,189, P < 0.001). In cholecystectomy patients, only 15.9% (10/63) developed colorectal adenomas, which was not significantly different from the control group. In a multivariate analysis controlling for sex, age, family history of colorectal cancer, alcohol, smoking, and body mass index, cholelithiasis was shown to be an independent risk factor for colorectal adenoma (adjusted OR 1.57, 95% CI 1.14–2.18). Cholelithiasis was strongly associated with multiple (≥3 lesions, adjusted OR 2.39, 95% CI 1.21–4.72) and left-sided colorectal adenomas (adjusted OR 1.82, 95% CI 1.28–2.59). CONCLUSIONS: Cholelithiasis is a risk factor for colorectal adenoma. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Obesity is thought to be associated with colorectal cancer and adenoma. We aimed to investigate the effect of body weight on the risk of colorectal adenoma both in cross-sectional and longitudinal analyses. METHODS: This is a retrospective cohort study in a large-scale health appraisal institution in Japan. A total of 7,963 asymptomatic, average-risk Japanese were enrolled at initial examinations, and 2,568 subjects who underwent a second colonoscopy after 1 yr were investigated. The association with the prevalence of colorectal adenoma was evaluated according to the body mass index (BMI) at the initial examination. The incidence of colorectal adenoma at the second colonoscopy was investigated according to the initial BMI and body weight changes during the year. RESULTS: The prevalence of colorectal adenoma increased in relation to increases in the BMI: 15.4%, 20.6%, 22.7%, and 24.2%, respectively, in the first (BMI < 21.350), second (21.350 ≤ BMI < 23.199), third (23.199 ≤ BMI < 25.156), and fourth (25.156 ≤ BMI) quartiles. The adjusted odds ratios in reference to Group Q1 were 1.15 (95% CI 0.97–1.37, P= 0.1) for Group Q2, 1.19 (1.01–1.41, P= 0.04) for Group Q3, and 1.32 (1.12–1.56, P= 0.001) for Group Q4. The incidence rates of colorectal adenoma after 1 yr also increased proportionally according to the initial BMI: Group Q1 (12.9%), Group Q2 (15.7%), Group Q3 (18.3%), and Group Q4 (19.0%). CONCLUSIONS: Obesity was associated with the risk for colorectal adenoma, and body weight reduction was suggested to decrease this risk. [ABSTRACT FROM AUTHOR]

Objective. In our previous study, we showed that the development of adenomas in the right-side colon increased with aging in subjects with no colorectal neoplasms. The aim of the present study was to investigate the location of metachronous colorectal adenomas after endoscopic polypectomy. Material and methods. The records of a colonoscopic follow-up study on 2900 subjects after polypectomy were analyzed. The location was classified as the right-side colon and left-side colon at the splenic flexure. Subjects were classified into three groups according to distribution of adenomas at the initial two colonoscopies: those with adenomas located only in the left side (LL), adenomas in both the left side and right side (LR), and adenomas only in the right side (RR). Distribution of initial and metachronous adenomas was evaluated according to age. Results. The annual incidence rates of colorectal adenomas in the left-side colon were estimated to be 8.56%, 11.2%, and 5.71% in the LL, LR, and RR groups, respectively. The rates in the right side were 5.91%, 15.5%, and 9.38%, respectively. The incidence rates in the left side in the age groups <40, 40-49, 50-59, and ≥60 years were 6.93%, 8.08%, 8.33%, and 8.48%/year, respectively. Those in the right side were 4.91%, 7.27%, 9.86%, and 12.41%/year, respectively. Conclusions. Although there may be individual predilection for right-side or left-side location of colorectal adenomas, aging tends to increase the number of adenomas in the right-side colon, while only modestly affecting those in the left-side colon. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although the immunochemical fecal occult blood test (FOBT) is reportedly more sensitive to large adenomas or colorectal cancer (CRC) than the guaiac-based FOBT, the sensitivity of the immunochemical FOBT to small adenomas has scarcely been reported. Previous reports have indicated that the guaiac-based FOBT can detect small adenomas only by serendipity. OBJECTIVES: To investigate the sensitivity of immunochemical FOBT to small adenomas using a large-scale cohort. METHODS: We analyzed 21,805 consecutively enrolled asymptomatic persons who underwent colonoscopy and immunochemical FOBT. RESULTS: The sensitivity to adenomas ≤9 mm was significantly higher than the false-positive rate as revealed by analysis of all eligible subjects (7.0% vs 4.5%, P < 0.001). In men, the sensitivity was superior to the false-positive rate and increased with age (<50 yr 6.1% and >60 yr 11.3%). On the other hand, the sensitivity in women was not significantly different from the false-positive rate in any generation (5.1% vs 4.7% for all eligible women, P= 0.72). CONCLUSIONS: Immunochemical FOBT detected a small percentage of small adenomas in men at a rate that is significantly higher than the false-positive rate. Studies comparing the guaiac and immunochemical FOBTs using the end point of CRC-related death are expected. [ABSTRACT FROM AUTHOR]

A 40-year-old Japanese man who developed upper abdominal pain, weight loss, and hypertension was diagnosed as suffering with polyarteritis nodosa (PAN) with lesions of the superior mesenteric artery (SMA). Three-dimensional computed tomographic angiography (3D-CTA) and conventional angiography revealed smooth segmental luminal narrowing of the branches of the SMA. In addition, an enhanced abdominal CT scan demonstrated diffuse thickening of the wall of the affected SMA. Treatment with high-dose corticosteroids resulted in immediate improvement of the abdominal manifestations and normalized the serum C-reactive protein levels. Furthermore, the subsequent enhanced CT and 3D-CTA revealed improvement of the wall thickening and luminal narrowing of the SMA and its branches during the treatment period. In addition to possessing the diagnostic usefulness of conventional angiography, 3D-CTA is also less invasive and facilitates the prompt and accurate diagnosis of PAN. Furthermore, thickening of the wall of medium-sized arteries evidenced by enhanced CT scan may also support a diagnosis of PAN. [ABSTRACT FROM AUTHOR]