16 research outputs found

    Magnon-induced non-Markovian friction of a domain wall in a ferromagnet

    Full text link
    Motivated by the recent study on the quasiparticle-induced friction of solitons in superfluids, we theoretically study magnon-induced intrinsic friction of a domain wall in a one-dimensional ferromagnet. To this end, we start by obtaining the hitherto overlooked dissipative interaction of a domain wall and its quantum magnon bath to linear order in the domain-wall velocity and to quadratic order in magnon fields. An exact expression for the pertinent scattering matrix is obtained with the aid of supersymmetric quantum mechanics. We then derive the magnon-induced frictional force on a domain wall in two different frameworks: time-dependent perturbation theory in quantum mechanics and the Keldysh formalism, which yield identical results. The latter, in particular, allows us to verify the fluctuation-dissipation theorem explicitly by providing both the frictional force and the correlator of the associated stochastic Langevin force. The potential for magnons induced by a domain wall is reflectionless, and thus the resultant frictional force is non-Markovian similarly to the case of solitons in superfluids. They share an intriguing connection to the Abraham-Lorentz force that is well-known for its causality paradox. The dynamical responses of a domain wall are studied under a few simple circumstances, where the non-Markovian nature of the frictional force can be probed experimentally. Our work, in conjunction with the previous study on solitons in superfluids, shows that the macroscopic frictional force on solitons can serve as an effective probe of the microscopic degrees of freedom of the system.Comment: 13 pages, 2 figure

    Gender differences in trends of bladder cancer mortality-to-incidence ratios according to health expenditure in 55 countries.

    No full text
    The association between bladder cancer mortality-to-incidence ratios (MIRs) and healthcare disparities has gender differences. However, no evidence supports gender as an issue in the association between changes in the MIR and health expenditures on bladder cancer. Changes in the MIR were defined as the difference in data from the years 2012 and 2018, which was named δMIR. Current health expenditures (CHE) and the human development index (HDI) were obtained from the World Health Organization and the Human Development Report Office. The association between variables was analyzed by Spearman's rank correlation coefficient. In total, 55 countries were analyzed according to data quality and the exclusion of missing data. Globally, the MIR changed according to the HDI level in both genders. Among the 55 countries studied, a high HDI and CHE were significantly associated with a favorable age-standardized rate-based MIR (ASR-based MIR) in both genders and the subgroups according to gender (for both genders, MIR vs. HDI: ρ = -0.720, p < 0.001; MIR vs. CHE per capita: ρ = -0.760, p < 0.001; MIR vs. CHE as a percentage of gross domestic product (CHE/GDP): ρ = -0.663, p < 0.001). Importantly, in females only, the CHE/GDP but neither the HDI score nor the CHE per capita was significantly associated with a favorable ASR-based δMIR (ASR-based δMIR vs. CHE/GDP: ρ = 0.414, p = 0.002). In the gender subgroups, the association between the HDI and the CHE was statistically significant for females and less significant for males. In conclusion, favorable bladder ASR-based MIRs were associated with a high CHE; however, improvement of the ASR-based δMIR data was more correlated with the CHE in females. Further investigation of the gender differences via a cohort survey with detailed information of clinical-pathological characteristics, treatment strategies, and outcomes might clarify these issues and improve therapeutic and/or screening strategies for bladder cancer

    Chylous ascites as a complication of nephroureterectomy

    Get PDF
    Chylous ascites may be the result of many pathological conditions, including congenital defects of the lymphatic system, nonspecific bacterial, parasitic and tuberculous peritoneal infection, liver cirrhosis, malignant neoplasm, blunt abdominal trauma, and surgical injury. A 62-year-old woman presented with chylous ascites after undergoing nephroureterectomy and bladder cuff excision for her left ureteral urothelial carcinoma. The diagnosis of chylous ascites is made when the ratio of ascitese versus serum triglyceride is > 2. Patients with chylous ascites may be treated conservatively with total parenteral nutrition and/or a diet containing low fat and medium chain triglycerides. Refractory cases may require more aggressive intervention. We report a case of postoperative chylous ascites that was treated successfully with total parenteral nutrition for 14 days. A review of the relevant literature is presented and chylous ascites treatment is also discussed

    Correlations between Mortality-to-Incidence Ratios and Health Care Disparities in Testicular Cancer

    No full text
    The mortality-to-incidence ratio (MIR) is associated with the clinical outcomes of different types of cancer as well as the ranking of health care systems. However, the association between MIRs for testicular cancer and health care disparities, including differences in expenditures and health system rankings, has not yet been reported. We used the Spearman&rsquo;s rank correlation coefficient (CC) to analyze the correlation between testicular cancer MIRs and both total expenditures on health/gross domestic product (e/GDP) and the World Health Organization&rsquo;s (WHO) health system rankings. After screening the data for quality and missing information, 57 countries were chosen for analysis. Generally, developed countries and regions had relatively high rates of incidence/mortality, but with a favorable MIR. Among the continents, Europe had the highest incidence rates, whereas the highest MIRs were in Africa. Globally, favorable testicular cancer MIRs were observed in countries with both a high e/GDP and a good WHO ranking (R2 = 0.325, p &lt; 0.001 and CC = &minus;0.568, p &lt; 0.001; R2 = 0.367, p &lt; 0.001 and CC = 0.655, p &lt; 0.001, respectively). In conclusion, the MIR for testicular cancer varies in countries and regions based on both their total health expenditure and their health care system ranking

    New Hydronephrosis in the Native Kidney Is Associated with the Development of De Novo Urinary Bladder Urothelial Carcinoma in Patients with Post-Kidney Transplantation

    No full text
    Increased malignancy after kidney transplantation (KT) is by far the most troublesome issue. Among these malignancies, urothelial carcinoma (UC) incidence is uniquely high in Taiwan. We want to know whether routine sonography to detect native hydronephrosis is associated with the development of de novo urinary bladder urothelial carcinoma (UBUC) in post-KT recipients. From 2003 to 2018, we retrospectively analyzed 1005 KT patients, 58 of whom were subsequently diagnosed with UBUC. The association between new native hydronephrosis and post-KT UBUC was analyzed with univariate and multivariate logistic regression analyses and a Kaplan–Meier plot. We excluded cases of people who had upper urinary tract urothelial carcinoma (UTUC) and were diagnosed prior to UBUC. There were 612 males (60.9%) and 393 females (39.1%), with a mean age of 48.2 ± 12.0 years old at KT. The mean follow-up period was 118.6 ± 70.2 months, and the diagnosis of UBUC from KT to UBUC was 7.0 ± 5.1 years. New native kidney hydronephrosis occurred more frequently in the UBUC group (56.4% versus 6.4%, p p < 0.001). UBUC in post-KT patients with native hydronephrosis also showed a tendency toward multifocal lesions upon presentation (47.8%). Post-KT UBUC is characterized by pathologically aggressive and multiple foci lesions. Native kidney hydronephrosis may be a deciding factor of post-KT UBUC

    Favorable mortality-to-incidence ratios of kidney Cancer are associated with advanced health care systems

    No full text
    Abstract Background The advancements in cancer therapy have improved the clinical outcomes of cancer patients in recent decades. However, advanced cancer therapy is expensive and requires good health care systems. For kidney cancer, no studies have yet established an association between clinical outcome and health care disparities. Methods We used the mortality-to-incidence ratio (MIR) for kidney cancer as a marker of clinical outcome to compare World Health Organization (WHO) country rankings and total expenditures on health/gross domestic product (e/GDP) using linear regression analyses. Results We included 57 countries based on data from the GLOBOCAN 2012 database. We found that more highly developed regions have higher crude and age-standardized rates of kidney cancer incidence and mortality, but a lower MIR, when compared to less developed regions. North America has the highest crude rates of incidence, but the lowest MIRs, whereas Africa has the highest MIRs. Furthermore, favorable MIRs are correlated with countries with good WHO rankings and high e/GDP expenditures (p < 0.001 and p = 0.013, respectively). Conclusions Kidney cancer MIRs are positively associated with the ranking of health care systems and health care expenditures
    corecore