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Polytetrafluoroethylene (PTFE) fine powder with 93% crystallinity was irradiated by an electron beam (EB) at various temperatures under a nitrogen atmosphere. Trapped free radicals in PTFE were studied using electron spin resonance (ESR) spectroscopy. The observed spectra of the samples exposed to air after irradiation at various temperatures showed asymmetrical signals, which are middle-chain type peroxide macroradicals derived from fluoroalkyl radicals. The radical yields at each irradiation temperature increased with increasing absorbed dose, and eventually saturated. The higher irradiation temperature resulted in higher radical yields when compared at the same exposed dose. Furthermore, the G-value of the radicals (G(R·)) increases with increasing irradiation temperatures corresponding to each relaxation and transition temperature. It is concluded that the chain reaction by the fluorine extraction from the main chain due to the end-chain radical generated via β-scission after dissociative electron attachment (DEA) is enhanced by the synergistic effect of heat and radiation.

BackgroundIn this study, survival and cause of death were investigated in patients with Crohn’s disease (CD) at a tertiary referral center.MethodsA database was created based on the medical records of 1108 CD patients who had a history of visiting our hospital to investigate background characteristics, cumulative survival rates from diagnosis, causes of death, and the standardized mortality ratio (SMR) for each cause of death. A follow-up questionnaire survey of patients followed up inadequately was also conducted. The cumulative survival rate from diagnosis was determined using the life table method and compared with that of a sex- and age-matched population model from the year 2000.ResultsThe study included 1108 patients whose mean age at diagnosis was 25.6 ± 10.8 years. The mean duration of follow-up was 14.6 ± 9.4 years, and there were 52 deaths. The cumulative survival rate was significantly lower 25 years after the diagnosis of CD (91.7%) than in the standard population model (95.7%). SMRs for both all causes [3.5; 95% confidence interval (CI): 2.7–4.6] and CD-specific causes (36.7; 95% CI 26.1–51.6) were high. Among the CD-specific causes, SMRs were especially high for small intestine and colorectal cancers, gastrointestinal diseases including intestinal failure (IF), perioperative complications, and amyloidosis.ConclusionThe SMRs for both all causes and CD-specific causes were high in CD patients. CD-specific causes including intestinal cancer, IF, perioperative complications, and amyloidosis showed especially high SMRs.

Bacterial colonization in infancy is considered crucial for the development of the immune system. Recently, there has been a drastic increase in childhood allergies in Japan. Therefore, we conducted a prospective study with 56 infants on the relationship between gut microbiota in the first year of life and the development of allergies during the first 3 years. In the lactation period, organic acid producers such as Leuconostoc, Weissella and Veillonella tended to be underrepresented in subjects who developed food allergies (FA, n = 14) within the first two years. In the weaning period, children in the FA group were highly colonized by unclassified Enterobacteriaceae and two Clostridium species closely related to Clostridium paraputrificum and C. tertium, and the whole tree phylogenetic diversity index was significantly lower in the FA group. All of these differences in the weaning period were statistically significant, even after adjusting for potential confounding factors. A higher abundance of unclassified Enterobacteriaceae was also found in the other allergic group (n = 15), whereas the two Clostridium species were highly specific to the FA group. The mode of action of these Clostridium species in childhood food allergies remains unknown, warranting further investigation.

We demonstrate the creation of a vector beam by tailoring geometric phase of left- and right- circularly polarized beams. Such a vector beam with a uniform phase has not been demonstrated before because a vortex phase remains in the beam. We focus on vortex phase cancellation to generate vector beams in terahertz regions, and measure the geometric phase of the beam and its spatial distribution of polarization. We conduct proof-of-principle experiments for producing a vector beam with radial polarization and uniform phase at 0.36 THz. We determine the vortex phase of the vector beam to be below 4%, thus highlighting the extendibility and availability of the proposed concept to the super broadband spectral region from ultraviolet to terahertz. The extended range of our proposed techniques could lead to breakthroughs in the fields of microscopy, chiral nano-materials, and quantum information science.

•Pneumococcal and influenza vaccine effectiveness against pneumonia was examined.•Analysis using respiratory medicine controls showed marginal vaccine effectiveness.•Bias in control selection leads to overestimation of vaccine effectiveness.•When selecting controls, vaccine recommendations by physicians should be considered.•We must try to evaluate vaccine effectiveness without selection bias. We conducted a case-control study to elucidate associations between pneumonia in elderly individuals and 23-valent pneumococcal polysaccharide vaccine (PPSV23) and seasonal influenza vaccine (influenza vaccine). Here, we examined selection of controls in our study using an analytic epidemiology approach. The study period was from October 1, 2009 through September 30, 2014. Cases comprised ≥65-year-old patients newly diagnosed with pneumonia. For every case with pneumonia, two patients with other diseases (one respiratory medicine, one non-respiratory medicine) who were sex-, age-, visit date- and visit hospital-matched were selected as controls. Odds ratios (ORs) and 95% confidence intervals (CIs) of vaccination for pneumonia were calculated using conditional logistic regression model. Similar analyses were also conducted based on the clinical department of controls. Analysis was conducted in 234 cases and 438 controls. Effectiveness of pneumococcal vaccination or influenza vaccination against pneumonia was not detected. Proportions of either vaccination in controls were greater among respiratory medicine (pneumococcal vaccine, 38%; influenza vaccine, 55%) than among non-respiratory medicine (23%; 48%). Analysis using controls restricted to respiratory medicine showed marginally significant effectiveness of pneumococcal vaccination (OR, 0.59; 95%CI, 0.34–1.03; P=0.064) and influenza vaccination (0.64; 0.40–1.04; 0.072). However, this effectiveness might have been overestimated by selection bias of controls, as pneumonia cases are not necessarily respiratory medicine patients. In the analysis using controls restricted to non-respiratory medicine, OR of pneumococcal vaccination for pneumonia was close to 1, presumably because the proportion of pneumococcal vaccination was higher in cases than in controls. Because pneumococcal vaccine was not routinely administered during the study period, differences in recommendations of vaccination by physician in different clinical departments might have greatly affected vaccination proportions. When we select controls, we should consider the background factors (underlying diseases, clinical department, etc.) which affect physicians’ recommendation of vaccination.

Background Brain-derived neurotrophic factor (BDNF) may play a role in glucose and lipid metabolism as well as mental health. We previously reported a negative association between BDNF levels and mental health in hemodialysis (HD) patients. Cardiovascular disease (CVD) is a common cause of death in patients undergoing HD. However, we have not yet evaluated the associations between serum BDNF levels and risk factors for CVD in HD patients. Methods A　cross-sectional study was conducted to evaluate the factors associated with serum BDNF levels in HD patients without active mental disorders. Seventy-seven HD patients were divided into two groups according to their serum BDNF levels: (i) the high BDNF group (BDNF > 12 ng/mL: n  = 39), and (ii) the low BDNF group (BDNF  ≤  12 ng/mL: n  = 38). Demographic and laboratory parameters were compared between the two groups. Results The values for total cholesterol, low-density lipoprotein (LDL) - cholesterol, body mass index, white blood cell count and platelet count were higher in the high BDNF group than in the low BDNF group. Higher serum total cholesterol levels, white blood cell counts and platelet counts were associated with an increased risk of higher serum BDNF levels even after controlling for age and sex. Furthermore, a higher platelet count remained a significant risk factor for higher BDNF levels even after controlling for higher total serum cholesterol levels and white blood cell counts. Conclusions Since platelets are suggested to play important roles not only in the initiation but also in the progression of atherosclerosis, BDNF might play a role in the development of atherosclerosis in patients on HD.

Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1–1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.

A large prospective cohort study in the United States examined the association between coffee intake and overall and cause-specific mortality and showed a inverse association between pneumonia and influenza deaths and coffee intake. In Japan, the mortality rate of pneumonia in elderly people is high, and its prevention is an important issue. The present study investigated the association between coffee and green tea intake and pneumonia among the elderly. The design was a hospital-based case control study. The cases were patients over 65 years old newly diagnosed as pneumonia. As a control, patients with the same sex and age (range of 5 years) who visited the same medical institution around the same time (within 2 months after examination of the case) for a disease other than pneumonia were selected. There were two controls per case. Odds ratio (OR) and 95% confidence interval (CI) for pneumonia of coffee and green tea intake during the past month were calculated using a conditional logistic regression model. A total of 199 cases and 374 controls were enrolled. When compared to those who do not drink coffee, the OR for pneumonia of those who drink less than one cup of coffee per day was 0.69 (95% CI 0.39–1.21), OR of those who drink one cup was 0.67 (0.38–1.18), and OR of those who drink two or more cups was 0.50 (0.28–0.88) (Trend p = 0.024). No association was found between pneumonia and green tea consumption. This study suggested a preventive association between coffee intake over 2 cups per day and pneumonia in the elderly.

Smoking is a risk factor for adult-onset Crohn’s disease (CD). Although passive smoking from family members is a major concern, especially in pediatric CD, the number of existing epidemiological studies is limited. This multicenter case–control study aimed to assess the effects of familial smoking on pediatric CD. We examined 22 pediatric CD cases and 135 controls. The subjects’ mothers were given a self-administered questionnaire about family smoking before disease onset in the CD group or the corresponding period in the control group. Univariable logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), whereas dose–response relationship analyses were performed for more in-depth evaluations. Univariable analyses indicated that passive smoking from the mother (OR, 2.09; 95% CI, 0.61–7.10) was not a significant, but a candidate risk factor for developing pediatric CD. In contrast, the dose–response relationship analyses revealed that passive smoking from the mother (OR, 1.17; 95% CI, 1.04–1.31) was significantly associated with pediatric CD. Therefore, passive smoking from the mother may be predominantly associated with the development of pediatric CD. Further follow-up studies comprising environmental measurements of passive smoking exposure doses and genetic factors interaction analysis are necessary.