119 research outputs found

    Single-Conductor Transmission-Line Model for Bent Wire Structures

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    A bend in a single-conductor line is a primary cause of radiation associated with the antenna mode; conversely, the radiation is fed back, resulting in attenuation and distortion of the current waveform. Despite being a fundamental phenomenon, its dynamics have not been sufficiently characterized. Therefore, this study presents a single-conductor transmission-line model for bent wire structures comprising multiple straight elements by using the local variables of charge per-unit-length and current along a thin conductor. The proposed model is validated over a wide frequency range using the method of moments. The total charge and current distributions that an external field induces on a bent structure are classified into three components: the scattering source distribution, traveling wave corresponding to the Sommerfeld mode, and radiation reaction. These components suggest an overall field-line coupling process: initially, an external electromagnetic field induces a scattering current in the structure, which in turn drives traveling and radiation-reaction currents at the ends, resulting in propagation along the line accompanied by radiation losses. The presented model is advantageous for designing electromagnetic phenomena corresponding to antennas and metamaterials and for addressing electromagnetic interference problems using passive circuit elements. A case study that makes use of the precise and descriptive model is included to predict the field emissions associated with the antenna mode around a bend

    Genetic Deletion of Vasohibin-2 Exacerbates Ischemia-Reperfusion-Induced Acute Kidney Injury

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    Acute kidney injury (AKI) has been increasingly recognized as a risk factor for transition to chronic kidney disease. Recent evidence suggests that endothelial damage in peritubular capillaries can accelerate the progression of renal injury. Vasohibin-2 (VASH2) is a novel proangiogenic factor that promotes tumor angiogenesis. However, the pathophysiological roles of VASH2 in kidney diseases remain unknown. In the present study, we examined the effects of VASH2 deficiency on the progression of ischemia-reperfusion (I/R) injury-induced AKI. I/R injury was induced by bilaterally clamping renal pedicles for 25 min in male wild-type (WT) andVash2homozygous knockout mice. Twenty-four hours later, I/R injury-induced renal dysfunction and tubular damage were more severe in VASH2-deficient mice than in WT mice, with more prominent neutrophil infiltration and peritubular capillary loss. After induction of I/R injury, VASH2 expression was markedly increased in injured renal tubules. These results suggest that VASH2 expression in renal tubular epithelial cells might be essential for alleviating I/R injury-induced AKI, probably through protecting peritubular capillaries and preventing inflammatory infiltration

    Effects of Highly Absorbable Curcumin in Patients with Impaired Glucose Tolerance and Non-Insulin-Dependent Diabetes Mellitus

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    Oxidative stress is enhanced by various mechanisms. Serum oxidized low-density lipoprotein (LDL) is a useful prognostic marker in diabetic patients with coronary artery disease. To examine the effects of Theracurmin®, a highly absorbable curcumin preparation, on glucose tolerance, adipocytokines, and oxidized LDL, we conducted a double-blind placebo-controlled parallel group randomized trial in patients with impaired glucose tolerance or non-insulin-dependent diabetes mellitus. We randomly divided the patients with impaired glucose tolerance or non-insulin-dependent diabetes mellitus and stable individuals into the placebo group and the Theracurmin® (180 mg daily for 6 months) group. Of the 33 patients analyzed, 18 (14 males and 4 females) were administered placebo and 15 (9 males and 6 females) were administered Theracurmin®. The patient characteristics did not differ between the two groups. The primary endpoint, HbA1c, did not differ significantly between the two groups. However, the level of α1-antitrypsin-low-density lipoprotein (AT-LDL), the oxidized LDL, significantly increased (p = 0.024) in the placebo group from the beginning of the trial up to 6 months, although there was no such change in the Theracurmin® group. The percentage change in BMI from the beginning of the trial up to 6 months tended to be higher in the Theracurmin® group than in the placebo group. Patients in the Theracurmin® group tended to have a larger percentage change in adiponectin and LDL-C than those in the placebo group. Patients in the Theracurmin® group showed a smaller percentage change in AT-LDL than those in the placebo group. This study suggests that the highly absorbable curcumin could potentially inhibit a rise in oxidized LDL in patients with impaired glucose tolerance or non-insulin-dependent diabetes mellitus. This trial is registered with UMIN000007361

    Anti-inflammatory Action of Curcumin and Its Use in the Treatment of Lifestyle-related Diseases

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    Chronic inflammation plays a significant role in lifestyle-related diseases, such as cardiovascular diseases and obesity/impaired glucose tolerance. Curcumin is a natural extract that possesses numerous physiological properties, as indicated by its anti-inflammatory action. The mechanisms underlying these effects include the inhibition of nuclear factor-kappaB and Toll-like receptor 4-dependent signalling pathways and the activation of a peroxisome proliferator-activated receptor-gamma pathway. However, the bioavailability of curcumin is very low in humans. To resolve this issue, several drug delivery systems have been developed and a number of clinical trials have reported beneficial effects of curcumin in the management of inflammation-related diseases. It is expected that evidence regarding the clinical application of curcumin in lifestyle-related diseases associated with chronic inflammation will accumulate over time

    The Synthetic Curcumin Analogue GO-Y030 Effectively Suppresses the Development of Pressure Overload-induced Heart Failure in Mice

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    Curcumin is a naturally occurring p300-histone acetyltransferase (p300-HAT) inhibitor that suppresses cardiomyocyte hypertrophy and the development of heart failure in experimental animal models. To enhance the therapeutic potential of curcumin against heart failure, we produced a series of synthetic curcumin analogues and investigated their inhibitory activity against p300-HAT. The compound with the strongest activity was further evaluated to determine its effects on cardiomyocyte hypertrophy and pressure overload-induced heart failure in mice. We synthesised five synthetic curcumin analogues and found that a compound we have named GO-Y030 most strongly inhibited p300-HAT activity. Furthermore, 1 μM GO-Y030, in a manner equivalent to 10 µM curcumin, suppressed phenylephrine-induced hypertrophic responses in cultured cardiomyocytes. In mice undergoing transverse aortic constriction surgery, administration of GO-Y030 at a mere 1% of an equivalently-effective dose of curcumin significantly attenuated cardiac hypertrophy and systolic dysfunction. In addition, this low dose of GO-Y030 almost completely blocked histone H3K9 acetylation and eliminated left ventricular fibrosis. A low dose of the synthetic curcumin analogue GO-Y030 effectively inhibits p300-HAT activity and markedly suppresses the development of heart failure in mice

    Gingival bleeding and pocket depth among smokers and the related changes after short-term smoking cessation

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    Background: Smoking is associated with the deteriorating health of the gingiva and periodontium. The long-term beneficial effects of smoking cessation on oral health are well known. However, the effects of short-term smoking cessation on gingival bleeding and periodontal pocket depth are unknown. The purpose of the present study was to determine the effects of short-term smoking cessation on gingival bleeding and periodontal pocket depth. Methods: Dentate smokers with a mean age of 56.9 ± 14.4 years at an outpatient smoking cessation clinic participated in this study. A professional dentist checked the periodontal pocket depth and gingival bleeding. Patients visited the smoking cessation clinic on their first visit and 2, 4, 8, and 12 weeks (three months). The gingival assessment was re-performed in those who succeeded in smoking cessation 3 months after the baseline. Results: The baseline data of 83 patients showed that an increase in pocket depth was associated with increasing age and the amount of smoking. A significant increase in gingival bleeding (p = .031) and increase in pocket depth (p = .046) were observed 3 months after the baseline in patients who successfully quit smoking (n = 14). Conclusion: Short-term smoking cessation increased periodontal pocket depth and gingival bleeding. These findings may reflect healing processes that occur in the healthy gingiva. Implications: Study findings will be useful to advise patients during smoking cessation programs. Dentists can inform patients that an initial increase in gingival bleeding and pocket depth could be associated with smoking cessation. Such advice will prevent patients from any apprehension that may cause them to recommence smoking

    アレルギー性気道炎症の性差の加齢変化-サイトカイン産生とプロゲステロンの影響に関する検討-

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    The incidence,severity and prognosis of asthma can be affected by a number of factors,including the patient\u27s age and sex.Clinical observations and epidemiologic studies indicate that the severity of asthma is higher among boys than girls,but that the ratio inverts after puberty.Thereafter,in the elderly,the sex difference disappears.However,the mechanisms underlying the age-related sex differences in the severity of asthma are not clear.Therefore,to clarify the mechanisms we compared using a murine model of asthma allergen-induced airway inflammation and the effect of progesterone on antigen-induced cytokine production by lymphocytes betoween the different age and sex.In 6 weeks old C57BL/6 mice,the airway inflammation in flammation in female mice sensitized with OVA followed by OVA inhalation was more severe than in male mice,whereas the sex difference in the airway inflammation was not observed in 16 weeks old mice.In not only 6 but also 16 weeks old mice,bronchial lymph nodes (BLN) cells from OVA-sensitized female mice produced more Th2 cytokine,than those from age-matched male mice,upon simulation with OVA.Progesterone did not significantly affect the sex difference in Th2 cytokine production by BLN cells in either 6 or 16 weeks old mice.Our findings suggest that the age-related sex differences in allergic airway inflammation are not due to simply the differences in lymphocytes function and sensiticities to progesterone

    The Synthetic Curcumin Analogue GO-Y030 Effectively Suppresses the Development of Pressure Overload-induced Heart Failure in Mice

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    Curcumin is a naturally occurring p300-histone acetyltransferase (p300-HAT) inhibitor that suppresses cardiomyocyte hypertrophy and the development of heart failure in experimental animal models. To enhance the therapeutic potential of curcumin against heart failure, we produced a series of synthetic curcumin analogues and investigated their inhibitory activity against p300-HAT. The compound with the strongest activity was further evaluated to determine its effects on cardiomyocyte hypertrophy and pressure overload-induced heart failure in mice. We synthesised five synthetic curcumin analogues and found that a compound we have named GO-Y030 most strongly inhibited p300-HAT activity. Furthermore, 1 μM GO-Y030, in a manner equivalent to 10 µM curcumin, suppressed phenylephrine-induced hypertrophic responses in cultured cardiomyocytes. In mice undergoing transverse aortic constriction surgery, administration of GO-Y030 at a mere 1% of an equivalently-effective dose of curcumin significantly attenuated cardiac hypertrophy and systolic dysfunction. In addition, this low dose of GO-Y030 almost completely blocked histone H3K9 acetylation and eliminated left ventricular fibrosis. A low dose of the synthetic curcumin analogue GO-Y030 effectively inhibits p300-HAT activity and markedly suppresses the development of heart failure in mice

    Thermoacclimation and genome adaptation of the membrane lipidome in marine Synechococcus

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    The marine cyanobacteria of the genus Synechococcus are important primary producers, displaying a wide latitudinal distribution that is underpinned by diversification into temperature ecotypes. The physiological basis underlying these ecotypes is poorly known. In many organisms, regulation of membrane fluidity is crucial for acclimating to variations in temperature. Here, we reveal the detailed composition of the membrane lipidome of the model strain Synechococcus sp. WH7803 and its response to temperature variation. Unlike freshwater strains, membranes are almost devoid of C18, mainly containing C14 and C16 chains with no more than two unsaturations. In response to cold, we observed a rarely observed process of acyl chain shortening that likely induces membrane thinning, along with specific desaturation activities. Both of these mechanisms likely regulate membrane fluidity, facilitating the maintenance of efficient photosynthetic activity. A comprehensive examination of 53 Synechococcus genomes revealed clade-specific gene sets regulating membrane lipids. In particular, the genes encoding desaturase enzymes, which is a key to the temperature stress response, appeared to be temperature ecotype-specific, with some of them originating from lateral transfers. Our study suggests that regulation of membrane fluidity has been among the important adaptation processes for the colonization of different thermal niches by marine Synechococcus
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