Comparison of low-concentration carbon dioxide-enriched and tap water immersion on body temperature after passive heating.

BACKGROUND: Because carbon dioxide (CO2)-enriched water causes cutaneous vasodilation, immersion in CO2-enriched water facilitates heat transfer from the body to the water or from the water to the body. Consequently, immersion in CO2-enriched water raises or reduces body temperature faster than immersion in fresh water. However, it takes time to dissolve CO2 in tap water and because the dissolved CO2 concentration decreases over time, the actual CO2 concentration is likely lower than the stated target concentration. However, it is unclear whether water containing a lower CO2 concentration would also cool the body faster than fresh water after body temperature had been increased. METHODS: Ten healthy males (mean age = 20 ± 1 years) participated in the study. Participants were first immersed for 15 min in a tap water bath at 40 °C to raise body temperature. They then moved to a tap water or CO2-enriched water bath at 30 °C to reduce body temperature. The CO2 concentration was set at 500 ppm. The present study measured cooling time and cooling rate (slope of the regression line relating auditory canal temperature (Tac) to cooling time) to assess the cooling effect of CO2-enriched water immersion. RESULTS: Immersion in 40 °C tap water caused Tac to rise 0.64 ± 0.25 °C in the tap water session and 0.62 ± 0.27 °C in the CO2-enriched water session (P > 0.05). During the 30 °C water immersion, Tac declined to the baseline within 13 ± 6 min in tap water and 10 ± 6 min in CO2-enriched water (P > 0.05). Cooling rates were 0.08 ± 0.06 °C/min in tap water and 0.08 ± 0.04 °C/min in CO2-enriched water (P > 0.05). CONCLUSIONS: CO2-enriched water containing 500 ppm CO2 did not cool faster than tap water immersion. This suggests that when the water temperature is 30 °C, a CO2 concentration of 500 ppm is insufficient to obtain the advantageous cooling effect during water immersion after body temperature has been increased.

Anomalous Flexural Elasticities of Graphene Membranes Unveiled by Manipulating Topology.

Mechanical behavior of atomically thin membranes is governed by bending rigidity and the Gaussian modulus. However, owing to methodological drawbacks, these two parameters have not been investigated sufficiently. We employed atomic force microscopy to demonstrate that the bending rigidity can be extracted from a quadratic relationship of adhesion energy with monolayer curvatures of rolled and unrolled graphene. The tip-induced topological defects revealed the Gaussian modulus; to the best of our knowledge, this is the first study on these parameters. Our study may hold great significance because existing investigations have been performed only on flat graphene. The configurational (strain) energy was evaluated via changes in the surface geometry, with subatomic resolution, by three-dimensional analyses of attractive interatomic forces. The mechanical parameters, evaluated at the hollow sites of the honeycomb lattice, were consistent with the isotropic elastic attributes. The remarkably large negative Gaussian modulus, observed when a single carbon atom was located at the center of the tip-induced bump, revealed attractive interactions between the topological defects and geometric potentials of the Gaussian curvature. Our approach will aid in developing two-dimensional materials and understanding cell biology.

A novel cooling method using carbon dioxide-rich water after passive heating.

In the event of a marked rise in body temperature, it is often necessary to reduce the temperature quickly. One method to rapidly drop body temperature is cold water immersion. Because carbon dioxide (CO2)-rich water causes cutaneous vasodilation, it may be that CO2-rich water reduces body temperature faster than fresh water. To test that idea, I compared the effects of CO2-rich and tap water immersion on auditory canal temperature (Tac) after passive heating. Nine healthy male subjects participated in the study. Subjects were first immersed for 15 min in a tap water bath at 40 °C to raise body temperature. They then moved to a tap water or CO2-rich water bath at 30 °C to reduce body temperature. Immersion in 40 °C tap water caused Tac to rise 0.64 ± 0.11 °C in the tap water session and 0.71 ± 0.25 °C in the CO2-rich water session (P > 0.05). During the 30 °C water immersion, Tac declined and was significantly lower in CO2-rich water than in tap water. Cooling rates were 0.06 ± 0.04 °C/min in tap water and 0.11 ± 0.05 °C/min in CO2-rich water (P < 0.05). In addition, both thermal sensation (3.2 ± 1.0 vs. 2.1 ± 0.9; P < 0.01) and thermal comfort (1.2 ± 0.4 vs. 2.1 ± 0.8; P < 0.01) were significantly better in CO2-rich water than tap water. These results suggest that CO2-rich water immersion reduces Tac 1.7 times faster than tap water immersion, and that CO2-rich water immersion cools the body more comfortably than tap water immersion.

Response to the "letter to the editor" by Sani Rachman Soleman et al., "spatiotemporal association of low birth weight with Cs-137 deposition at the prefecture level in Japan after the Fukushima nuclear power plant accidents".

We thank Sani Rachman Soleman et al. for three specific points of criticism concerning our investigation of the ecological association between low birth weight (LBW) and radioactive contamination in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accidents: 1. Ecological variables are not justified enough to adjust potential confounding. 2. The spatiotemporal regression model does not consider temporal reduction in radiation dose rate. 3. Dose-response plot between dose rates and odds ratios overestimates R2 and underestimates p-value. This criticism is a good starting point to explain some of the technical backgrounds of our approach in more detail.

Spatiotemporal association of low birth weight with Cs-137 deposition at the prefecture level in Japan after the Fukushima nuclear power plant accidents: an analytical-ecologic epidemiological study.

BACKGROUND: Perinatal mortality increased in contaminated prefectures after the Fukushima Daichi Nuclear Power Plant (FDNPP) accidents in Japan in 2011. Elevated counts of surgeries for cryptorchidism and congenital heart malformations were observed throughout Japan from 2012 onward. The thyroid cancer detection rate (2011 to 2016) was associated with the dose-rate at the municipality level in the Fukushima prefecture. Since the birth weight is a simple and objective indicator for gestational development and pregnancy outcome, the question arises whether the annual birth weight distribution was distorted in a dose-rate-dependent manner across Japan after Fukushima. METHODS: The Japanese Ministry of Health, Labour, and Welfare provides prefecture-specific annual counts for 26.158 million live births from 1995 to 2018, of which 2.366 million births (9.04%) with weights < 2500 g. Prefecture-specific spatiotemporal trends of the low birth weight proportions were analyzed. Logistic regression allowing for level-shifts from 2012 onward was employed to test whether those level-shifts were proportional to the prefecture-specific dose-rates derived from Cs-137 deposition in the 47 Japanese prefectures. RESULTS: The overall trend of the low birth weight prevalence (LBWp) in Japan discloses a jump in 2012 with a jump odds ratio (OR) 1.020, 95%-confidence interval (1.003,1.037), p-value 0.0246. A logistic regression of LBWp on the additional dose-rate after the FDNPP accidents adjusted for prefecture-specific spatiotemporal base-line trends yields an OR per µSv/h of 1.098 (1.058, 1.139), p-value < 0.0001. Further adjusting the logistic regression for the annual population size and physician density of the prefectures, as well as for the counts of the dead, the missing, and the evacuees due to earthquake and tsunami (as surrogate measures for medical infrastructure and stress) yields an OR per µSv/h of 1.109 (1.032, 1.191), p-value 0.0046. CONCLUSIONS: This study shows increased low birth weight prevalence related to the Cs-137 deposition and the corresponding additional dose-rate in Japan from 2012 onward. Previous evidence suggesting compromised gestational development and pregnancy outcome under elevated environmental ionizing radiation exposure is corroborated.

Association between the detection rate of thyroid cancer and the external radiation dose-rate after the nuclear power plant accidents in Fukushima, Japan.

A thyroid cancer ultrasonography screening for all residents 18 years old or younger living in the Fukushima prefecture started in October 2011 to investigate the possible effect of the radiological contamination after the Fukushima Daiichi Nuclear Power Plant accidents as of March 12 to 15, 2011. Thyroid cancer in 184 cases was reported by February 2017. The question arises to which extent those cancer cases are a biological consequence of the radiation exposure or an artefactual result of the intense screening of a large population.Experiences with the Chernobyl accident suggest that the external dose may be considered a valid surrogate for the internal dose of the thyroid gland. We, therefore, calculated the average external effective dose-rate (µSv/h) for the 59 municipalities of the Fukushima prefecture based on published data of air and soil radiation. We further determined the municipality-specific absolute numbers of thyroid cancers found by each of the two screening rounds in the corresponding municipality-specific exposed person-time observed. A possible association between the radiation exposure and the thyroid cancer detection rate was analyzed with Poisson regression assuming Poisson distributed thyroid cancer cases in the exposed person-time observed per municipality.The target populations consisted of 367,674 and 381,286 children and adolescents for the 1st and the 2nd screening rounds, respectively. In the 1st screening, 300,476 persons participated and 270,489 in the 2nd round. From October 2011 to March 2016, a total of 184 cancer cases were found in 1,079,786 person-years counted from the onset of the exposure to the corresponding examination periods in the municipalities. A significant association between the external effective dose-rate and the thyroid cancer detection rate exists: detection rate ratio (DRR) per µSv/h 1.065 (1.013, 1.119). Restricting the analysis to the 53 municipalities that received less than 2 µSv/h, and which represent 176 of the total 184 cancer cases, the association appears to be considerably stronger: DRR per µSv/h 1.555 (1.096, 2.206).The average radiation dose-rates in the 59 municipalities of the Fukushima prefecture in June 2011 and the corresponding thyroid cancer detection rates in the period October 2011 to March 2016 show statistically significant relationships.

Effect of food intake on respiratory chemosensitivity to CO2 in young adults.

BACKGROUND: Food intake augments CO2 production; however, minute ventilation is not augmented during exercise after food intake. Respiratory chemoreceptors respond to CO2 and influence respiration. We examined the effect of food intake on respiratory chemosensitivity to CO2 in young adults. METHODS: The hypercapnic ventilatory response was measured in eleven healthy individuals before and after food intake. To evaluate the respiratory chemoreflex response to CO2, minute ventilation was plotted against end-tidal PCO2 using data obtained with the rebreathing method. RESULTS: Sublingual temperature, CO2 output, minute ventilation, and end-tidal PCO2 were all significantly higher at baseline in the session after food intake than in the session before food intake. On the other hand, there was no significant difference in chemosensitivity to CO2 between the sessions before and after food intake (1.60 ± 0.62 vs. 1.53 ± 0.62 l min-1 mmHg-1). CONCLUSIONS: Food intake does not influence respiratory chemosensitivity to CO2 in young adults, which is different from infants. This suggests that control of respiration differs between young adults and infants and that the elevated minute ventilation after food intake in young adults is not caused by a change in respiratory chemosensitivity.

Effect of food intake on the ventilatory response to increasing core temperature during exercise.

Food intake increases metabolism and body temperature, which may in turn influence ventilatory responses. Our aim was to assess the effect of food intake on ventilatory sensitivity to rising core temperature during exercise. Nine healthy male subjects exercised on a cycle ergometer at 50% of peak oxygen uptake in sessions with and without prior food intake. Ventilatory sensitivity to rising core temperature was defined by the slopes of regression lines relating ventilatory parameters to core temperature. Mean skin temperature, mean body temperature (calculated from esophageal temperature and mean skin temperature), oxygen uptake, carbon dioxide elimination, minute ventilation, alveolar ventilation, and tidal volume (VT) were all significantly higher at baseline in sessions with food intake than without food intake. During exercise, esophageal temperature, mean skin temperature, mean body temperature, carbon dioxide elimination, and end-tidal CO2 pressure were all significantly higher in sessions with food intake than without it. By contrast, ventilatory parameters did not differ between sessions with and without food intake, with the exception of VT during the first 5 min of exercise. The ventilatory sensitivities to rising core temperature also did not differ, with the exception of an early transient effect on VT. Food intake increases body temperature before and during exercise. Other than during the first 5 min of exercise, food intake does not affect ventilatory parameters during exercise, despite elevation of both body temperature and metabolism. Thus, with the exception of an early transient effect on VT, ventilatory sensitivity to rising core temperature is not affected by food intake.

Unilateral rostral mandibulectomy for gingival vascular hamartoma in two calves.

A 2-month-old female Holstein calf and a 5-month-old female Japanese black calf presented with gingival vascular hamartoma located in the interdental space between the second and third mandibular incisors in the right and left mandibles, respectively. On radiographic or computed tomographic images, osteolytic changes appeared within the mandibular bones adjacent to the masses. The masses were removed along with affected mandibular bone by using unilateral rostral mandibulectomy. After surgery, both cases exhibited a normal appetite and grew normally, with no cosmetic changes or recurrences. Unilateral rostral mandibulectomy can be applied for invasive gingival vascular hamartomas associated with osteolytic changes.

Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan: A spatially stratified longitudinal study.

Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or confounders, intensified research in various scientific disciplines is urgently needed to better qualify and quantify the association of natural and artificial environmental radiation with detrimental genetic health effects at the population level.

Characteristics of hyperthermia-induced hyperventilation in humans.

In humans, hyperthermia leads to activation of a set of thermoregulatory responses that includes cutaneous vasodilation and sweating. Hyperthermia also increases ventilation in humans, as is observed in panting dogs, but the physiological significance and characteristics of the hyperventilatory response in humans remain unclear. The relative contribution of respiratory heat loss to total heat loss in a hot environment in humans is small, and this hyperventilation causes a concomitant reduction in arterial CO2 pressure (hypocapnia), which can cause cerebral hypoperfusion. Consequently, hyperventilation in humans may not contribute to the maintenance of physiological homeostasis (i.e., thermoregulation). To gain some insight into the physiological significance of hyperthermia-induced hyperventilation in humans, in this review, we discuss 1) the mechanisms underlying hyperthermia-induced hyperventilation, 2) the factors modulating this response, and 3) the physiological consequences of the response.

Effect of postprandial thermogenesis on the cutaneous vasodilatory response during exercise.

To examine the effect of postprandial thermogenesis on the cutaneous vasodilatory response, 10 healthy male subjects exercised for 30 min on a cycle ergometer at 50% of peak oxygen uptake, with and without food intake. Mean skin temperature, mean body temperature (Tb), heart rate, oxygen uptake, carbon dioxide elimination, and respiratory quotient were all significantly higher at baseline in the session with food intake than in the session without food intake. To evaluate the cutaneous vasodilatory response, relative laser Doppler flowmetry values were plotted against esophageal temperature (Tes) and Tb. Regression analysis revealed that the [Formula: see text] threshold for cutaneous vasodilation tended to be higher with food intake than without it, but there were no significant differences in the sensitivity. To clarify the effect of postprandial thermogenesis on the threshold for cutaneous vasodilation, the between-session difference in the Tes threshold and the Tb threshold were plotted against the between-session difference in baseline Tes and baseline Tb, respectively. Linear regression analysis of the resultant plot showed significant positive linear relationships (Tes: r = 0.85, P < 0.01; Tb: r = 0.67, P < 0.05). These results suggest that postprandial thermogenesis increases baseline body temperature, which raises the body temperature threshold for cutaneous vasodilation during exercise.

HDlive imaging of fetal enteric duplication cyst.

Enteric duplication cysts are rare congenital anomalies, but their antenatal diagnosis is becoming more common because of advances in ultrasonography. With the latest state-of-the-art technology, HDlive facilitates a more realistic anatomical visualization of different fetal organ structures, making diagnosis more precise. We present a case of antenatal HDlive imaging of an enteric duplication cyst. A 26-year-old pregnant Japanese woman was referred to our ultrasound clinic because of a fetal intra-abdominal cyst at 27 weeks of gestation. Two-dimensional (2D) ultrasound revealed a sonolucent, ellipsoid structure in the subhepatic area. Magnetic resonance imaging yielded the same findings. However, irregular internal echoes appeared at 33 weeks of gestation. There was no vascularity on color Doppler. HDlive clearly depicted a more realistic image of the circular mass, which was thick walled, with a large amount of debris inside, and showed no communication with adjacent structures. Careful monitoring was conducted for these unusual findings. A day after delivery, an emergency operation was performed because the infant had sudden signs and symptoms of obstruction. Intra-operative findings were ileus and a necrotic ileal duplication cyst confirmed by histopathologic studies. Complications of enteric duplication cyst can arise at any time of life, and so thorough monitoring may be recommended. The findings of irregular internal echoes and a large amount of debris inside the cyst are relatively characteristic features of a complicated cyst. HDlive gives us additional information on the actual appearance of a complicated cyst that may be difficult to obtain using conventional 2D sonography alone. HDlive can be very useful in the antenatal surveillance of enteric duplication cysts.

Chronological shifts and changing causes of death after radiotherapy for early-stage oral cancer.

BACKGROUND: Following recent improvements in the curability of oral cancer, chronological shifts and changes in the causes of death after treatment have been observed. We conducted a review of the post-treatment causes of death following radiotherapy for oral cancers. MATERIALS AND METHODS: The medical records of 966 patients with early-stage (stage I and II) oral cancer treated at our institute between 1980 and 2001 were reviewed, and the chronological shifts and changes in the causes of death after radiotherapy were assessed. RESULTS: Of the 966 patients enrolled in this study, 365 have died to date. Two hundred and eleven patients died of their primary malignancy; 193 of these deaths occurred within 5 years of treatment for the primary oral cancer. The second most frequent cause of death was second primary cancer (n = 90). Twenty-three patients with head and neck cancers and 18 patients with esophageal cancers died within 10 years of radiotherapy, and six patients with lung cancers died after more than 10 years. CONCLUSION: Within the first 5 years following treatment, the major cause of death was the primary oral cancer. After 5-10 years, a second primary cancer, such as head and neck cancer or esophageal cancer, became the leading cause of death. Over a 10-year period, the proportion of deaths from a second primary cancer in the lung was significant. We have demonstrated that there are chronological shifts and changes in the causes of death following treatment for early-stage oral cancer.

198Au grain implantation for early tongue cancer in patients of advanced age or poor performance status.

Brachytherapy using (198)Au grains is minimally invasive and the only curative treatment for early tongue cancer in patients of advanced age or poor performance status available in our institution. From March 1993 to February 2008, (198)Au grains were used to treat a group of 96 Stage I-II tongue cancer patients who could not undergo surgery or brachytherapy using (192)Ir pins because of an advanced age (≥75 years) or poor performance status (≥2). The patients were followed for 3.9 ± 3.3 years, and the cause-specific survival and local control rates were determined. Survival analyses were performed using the Kaplan-Meier method, and univariate and multivariate analyses were performed using the Cox proportional hazard model. The results were compared with those for a group of 193 early tongue-cancer patients who underwent treatment using iridium pins. The 5-year cause-specific survival and local control rates of the (198)Au grains group were 71% and 68%, respectively, both of which were 16% lower than the corresponding rates for the (192)Ir pins group. Our study demonstrated that as the last curative treatment available, (198)Au grain implantation could be used to achieve moderate treatment results for early tongue cancer in patients of advanced age or poor performance status.