Characterizing Delaunay Graphs via Fixed Point Theorem

Abstract This paper discusses a problem for determining whether a given plane graph is a Delaunay graph, i.e., whether it is topologically equivalent to a Delaunay triangulation. There exists a theorem which characterizes Delaunay graphs and yields a polynomial time algorithm for the problem only by solving a certain linear inequality system. The theorem was proved by Rivin based on arguments of hyperbolic geometry. Independently, Hiroshima, Miyamoto and Sugihara gave another proof of the theorem based on primitive arguments on Euclidean geometry. Unfortunately, the existing proofs of the theorem are rather difficult or long. In this paper, we give a simple proof of the theorem characterizing Delaunay graphs, which is based on the fixed point theorem

Impact of human papillomavirus types on uterine cervical neoplasia

Taguchi A., Yoshimoto D., Kusakabe M., et al. Impact of human papillomavirus types on uterine cervical neoplasia. Journal of Obstetrics and Gynaecology Research, (2024); https://doi.org/10.1111/jog.15995.Human papillomavirus (HPV) is a major cause of cervical cancer. As the natural history of HPV-associated cervical lesions is HPV genotype-dependent, it is important to understand the characteristics of these genotypes and to manage them accordingly. Among high-risk HPVs, HPV16 and 18 are particularly aggressive, together accounting for 70% of HPV genotypes detected in cervical cancer. Other than HPV16 and 18, HPV31, 33, 35, 45, 52, and 58 are also at a high risk of progression to cervical intraepithelial neoplasia (CIN)3 or higher. Recent studies have shown that the natural history of HPV16, 18, 52, and 58, which are frequently detected in Japan, depends on the HPV genotype. For example, HPV16 tends to progress in a stepwise fashion from CIN1 to CIN3, while HPV52 and 58 are more likely to persist in the CIN1 to CIN2 state. Among the high-risk HPVs, HPV18 has some peculiar characteristics different from those of other high-risk HPV types; the detection rate in precancerous lesions is much lower than those of other high-risk HPVs, and it is frequently detected in highly malignant adenocarcinoma and small cell carcinoma. Recent findings demonstrate that HPV18 may be characterized by latent infection and carcinogenesis in stem cell-like cells. In this context, this review outlines the natural history of HPV-infected cervical lesions and the characteristics of each HPV genotype

The Index of Exercise Tolerance in Heart Failure with Preserved Ejection Fraction is Gait Speed

Introduction: Exercise tolerance, an important factor affecting life prognosis and rehospitalization in patients with chronic heart failure, is a major outcome of cardiac rehabilitation. Heart failure with preserved ejection fraction (HFpEF) from reduced diastolic capacity has recently increased among patients with chronic heart failure. This study evaluated and clarified the factors indicating exercise tolerance in patients with HFpEF from various perspectives, including cardiac and skeletal muscle functions. Material and Methods: The subjects were 31 patients with HFpEF who underwent cardiac rehabilitation. Exercise tolerance was assessed using a 6-minute walking test. Physical function, physical activity, body composition test, baseline characteristics, blood data, and echocardiography results were extracted from medical records to identify the indicators of exercise tolerance. Results: Gait speed was significantly different in exercise tolerance for HFpEF patients (β=0.75, p<0.01). Unlike HFrEF, HFpEF were no significant differences in brain natriuretic peptide (BNP) levels and cardiac function. Conclusion: Gait speed is an indicator of exercise tolerance in HFpEF patients. However, its pathological course differs from HFrEF, indicating that it is poorly related to BNP, a biomarker for heart failure and cardiac function

Impact of renal insufficiency on long-term clinical outcome in patients with heart failure treated by cardiac resynchronization therapy

AbstractBackgroundRenal insufficiency is recognized as a predictor of mortality and adverse outcome in heart failure (HF) patients. However, the long-term clinical outcome of cardiac resynchronization therapy (CRT) in Japanese HF patients with renal insufficiency remains uncertain.MethodsWe evaluated 67 consecutive patients who underwent CRT at our hospital. The patients were divided into two groups according to a baseline estimated glomerular filtration rate (e-GFR) cut-off value of 50ml/min, which is defined as the time at which patients should be referred to a nephrologist, by the Japanese Society of Nephrology. Follow-up echocardiographic findings and renal function were examined at 3–6 months after CRT. Then, we compared long-term clinical outcomes between the two groups, and analyzed the effect of CRT on renal function, echocardiographic parameters and cardiac survival.ResultsDuring a mean follow-up period of 30.3 months, patients with advanced renal insufficiency (e-GFR<50ml/min) had significant higher all-cause mortality (log-rank p=0.033) and higher cardiac mortality combined with HF hospitalization (log-rank p=0.017) than patients with e-GFR≥50ml/min. Multivariate analysis revealed that advanced renal insufficiency was an independent predictor of cardiac mortality combined with HF hospitalization (odds ratio=3.01, p=0.008). Subgroup analysis in the baseline advanced renal insufficiency group revealed that patients with preserved renal function by CRT (<10% reduction in e-GFR) had a higher rate of decrease of left ventricular end-systolic diameter (−14.0% vs. −0.8%, p=0.023) and lower cardiac mortality combined with HF hospitalization (log-rank p=0.029) compared with patients with deterioration of renal function (≥10% reduction in e-GFR).ConclusionsThe present study suggests that advanced renal insufficiency is quite useful for the prediction of worsening clinical outcomes in HF patients treated by CRT. Preservation of renal function by CRT brings about better cardiac survival through prevention of adverse cardiac events, even in HF patients with advanced renal insufficiency

A comprehensive survey on quantum computer usage: How many qubits are employed for what purposes?

Quantum computers (QCs), which work based on the law of quantum mechanics, are expected to be faster than classical computers in several computational tasks such as prime factoring and simulation of quantum many-body systems. In the last decade, research and development of QCs have rapidly advanced. Now hundreds of physical qubits are at our disposal, and one can find several remarkable experiments actually outperforming the classical computer in a specific computational task. On the other hand, it is unclear what the typical usages of the QCs are. Here we conduct an extensive survey on the papers that are posted in the quant-ph section in arXiv and claim to have used QCs in their abstracts. To understand the current situation of the research and development of the QCs, we evaluated the descriptive statistics about the papers, including the number of qubits employed, QPU vendors, application domains and so on. Our survey shows that the annual number of publications is increasing, and the typical number of qubits employed is about six to ten, growing along with the increase in the quantum volume (QV). Most of the preprints are devoted to applications such as quantum machine learning, condensed matter physics, and quantum chemistry, while quantum error correction and quantum noise mitigation use more qubits than the other topics. These imply that the increase in QV is fundamentally relevant, and more experiments for quantum error correction, and noise mitigation using shallow circuits with more qubits will take place.Comment: 14 pages, 5 figures, figures regenerate

Effect of Focal X-ray Irradiation on Experimental Choroidal Neovascularization

PURPOSE. Radiation therapy has been used to treat choroidal neovascularization (CNV) in patients with age-related macular degeneration. The in vivo effect of applying focal x-ray irradiation to the eye of rabbits with experimental CNV was investigated. METHODS. CNV was induced in the rabbit eyes by subretinal implantation of gelatin hydrogel microspheres impregnated with basic fibroblast growth factor. Three weeks after implantation, 17 of 34 eyes with CNV lesions accompanied by fluorescein leakage were irradiated with a single dose of 20 Gy; the other 17 eyes were not irradiated and served as the controls. The eyes were examined before irradiation and 1, 2, and 4 weeks after irradiation, by indirect ophthalmoscopy and fluorescein angiography. The degree of a decreasing amount of fluorescein leakage from the CNV lesions after irradiation was graded using a computerized image analysis system and was compared in the irradiated and nonirradiated eyes. These eyes were also examined histologically and immunohistochemically. RESULTS. Fluorescein leakage from the CNV lesions had significantly decreased in the eyes irradiated with 20 Gy compared with the control eyes, throughout the study period (P &lt; 0.05). Histologic and immunohistochemical studies at 4 weeks after irradiation demonstrated that the degree of vascular formation and the number of vascular endothelial cells in the subretinal membrane of the irradiated eyes were less than those of the control eyes. CONCLUSIONS. Focal x-ray irradiation at the ocular region effectively reduced experimental CNV activity. These results support the possibility that radiation therapy may be beneficial in treating CNV. (Invest Ophthalmol Vis Set. 1999;40:l496-1502

Boulder size and shape distributions on asteroid Ryugu

In 2018, the Japanese spacecraft Hayabusa2, arrived at the small asteroid Ryugu. The surface of this C-type asteroid is covered with numerous boulders whose size and shape distributions are investigated in this study. Using a few hundred Optical Navigation Camera (ONC) images with a pixel scale of approximately 0.65 m, we focus on boulders greater than 5m in diameter. Smaller boulders are also considered using five arbitrarily chosen ONC close-up images with pixel scales ranging from 0.7 to 6 cm. Across the entire surface area (~2.7 km2) of Ryugu, nearly 4400 boulders larger than 5m were identified. Boulders appear to be uniformly distributed across the entire surface, with some slight differences in latitude and longitude. At ~50 km−2, the number density of boulders larger than 20m is twice as large as on asteroid Itokawa (or Bennu). The apparent shapes of Ryugu's boulders resemble laboratory impact fragments, with larger boulders being more elongated. The ratio of the total volume of boulders larger than 5m to the total excavated volume of craters larger than 20m on Ryugu can be estimated to be ~94%, which is comparatively high. These observations strongly support the hypothesis that most boulders found on Ryugu resulted from the catastrophic disruption of Ryugu's larger parent body, as described in previous papers (Watanabe et al., 2019; Sugita et al.,2019). The cumulative size distribution of boulders larger than 5 m has a power-index of −2.65 ± 0.05, which is comparatively shallow compared with other asteroids visited by spacecraft. For boulders smaller than 4 m, the power-index is even shallower and ranges from −1.65 ± 0.05 to −2.01 ± 0.06. This particularly shallow power-index implies that some boulders are buried in Ryugu's regolith. Based on our observations, we suggest that boulders near the equator might have been buried by the migration of finer material and, as a result, the number density of boulders larger than 5 m in the equatorial region is lower than at higher latitudes

Resveratrol promotes expression of SIRT1 and StAR in rat ovarian granulosa cells: an implicative role of SIRT1 in the ovary

<p>Abstract</p> <p>Background</p> <p>Resveratrol is a natural polyphenolic compound known for its beneficial effects on energy homeostasis, and it also has multiple properties, including anti-oxidant, anti-inflammatory, and anti-tumor activities. Recently, silent information regulator genes (Sirtuins) have been identified as targets of resveratrol. Sirtuin 1 (SIRT1), originally found as an NAD⁺-dependent histone deacetylase, is a principal modulator of pathways downstream of calorie restriction, and the activation of SIRT1 ameliorates glucose homeostasis and insulin sensitivity. To date, the presence and physiological role of SIRT1 in the ovary are not known. Here we found that SIRT1 was localized in granulosa cells of the human ovary.</p> <p>Methods</p> <p>The physiological roles of resveratrol and SIRT1 in the ovary were analyzed. Immunohistochemistry was performed to localize the SIRT1 expression. SIRT1 protein expression of cultured cells and luteinized human granulosa cells was investigated by Western blot. Rat granulosa cells were obtained from diethylstilbestrol treated rats. The cells were treated with increasing doses of resveratrol, and subsequently harvested to determine mRNA levels and protein levels. Cell viability was tested by MTS assay. Cellular apoptosis was analyzed by caspase 3/7 activity test and Hoechst 33342 staining.</p> <p>Results</p> <p>SIRT1 protein was expressed in the human ovarian tissues and human luteinized granulosa cells. We demonstrated that resveratrol exhibited a potent concentration-dependent inhibition of rat granulosa cells viability. However, resveratrol-induced inhibition of rat granulosa cells viability is independent of apoptosis signal. Resveratrol increased mRNA levels of SIRT1, LH receptor, StAR, and P450 aromatase, while mRNA levels of FSH receptor remained unchanged. Western blot analysis was consistent with the results of quantitative real-time RT-PCR assay. In addition, progesterone secretion was induced by the treatment of resveratrol.</p> <p>Conclusions</p> <p>These results suggest a novel mechanism that resveratrol could enhance progesterone secretion and expression of luteinization-related genes in the ovary, and thus provide important implications to understand the mechanism of luteal phase deficiency.</p

Genotype-Dependent Efficacy of a Dual PI3K/mTOR Inhibitor, NVP-BEZ235, and an mTOR Inhibitor, RAD001, in Endometrial Carcinomas

The PI3K (phosphatidylinositol-3-kinase)/mTOR (mammalian target of rapamycin) pathway is frequently activated in endometrial cancer through various PI3K/AKT-activating genetic alterations. We examined the antitumor effect of NVP-BEZ235—a dual PI3K/mTOR inhibitor—and RAD001—an mTOR inhibitor—in 13 endometrial cancer cell lines, all of which possess one or more alterations in PTEN, PIK3CA, and K-Ras. We also combined these compounds with a MAPK pathway inhibitor (PD98059 or UO126) in cell lines with K-Ras alterations (mutations or amplification). PTEN mutant cell lines without K-Ras alterations (n = 9) were more sensitive to both RAD001 and NVP-BEZ235 than were cell lines with K-Ras alterations (n = 4). Dose-dependent growth suppression was more drastically induced by NVP-BEZ235 than by RAD001 in the sensitive cell lines. G1 arrest was induced by NVP-BEZ235 in a dose-dependent manner. We observed in vivo antitumor activity of both RAD001 and NVP-BEZ235 in nude mice. The presence of a MEK inhibitor, PD98059 or UO126, sensitized the K-Ras mutant cells to NVP-BEZ235. Robust growth suppression by NVP-BEZ235 suggests that a dual PI3K/mTOR inhibitor is a promising therapeutic for endometrial carcinomas. Our data suggest that mutational statuses of PTEN and K-Ras might be useful predictors of sensitivity to NVP-BEZ235 in certain endometrial carcinomas