Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or

Patchable and Implantable 2D Nanogenerator

With the development of technology, electronic devices are becoming more miniaturized and multifunctional. With the development of small electronic devices, they are changing from the conventional accessory type, which is portable, to the patchable type, which can be attached to a person's apparel or body, and the eatable/implantable type, which can be directly implanted into the human body. In this regard, it is necessary to address various technical issues, such as high-capacity/high-efficiency small-sized battery technology, component miniaturization, low power technology, flexible technology, and smart sensing technology. In addition, there is a demand for self-powered wireless systems in particular devices. A piezoelectric/triboelectric nanogenerator (PENG/TENG) can generate electric energy from small amounts of mechanical energy such as from blood flow and heartbeats in the human body as well as human movement, so it is expected that it will enable the development of self-powered wireless systems. Due to their unique properties, such as flexibility, transparency, mechanical stability, and nontoxicity, 2D materials are optimal materials for the development of implantable and patchable self-powered nanodevices in the human body. In this Review, the studies related to patchable and implantable devices for the human body using PENGs/TENGs based on 2D materials are discussed. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim1

Patterns of Utilization and Clinical Adoption of 0.35 MR-Guided Radiation Therapy in the United States — Understanding the Transition to Adaptive, Ultra-Hypofractionated Treatments

Magnetic resonance imaging-guided radiation therapy (MRgRT) utilization is rapidly expanding worldwide, driven by advanced capabilities including continuous intrafraction visualization, automatic triggered beam delivery, and on-table adaptive replanning. Our objective was to describe patterns of 0.35T-MRgRT utilization in the United States (US) among early adopters of this novel technology. Anonymized administrative data from all US 0.35T-MRgRT treatment systems were extracted for patients completing treatment from 2014-2020. Detailed treatment information was available for all 0.35T-MR Linac system and some cobalt system patients. Most cobalt patients were included in total only. 17 systems at 16 centers treated 5,733 patients, delivering 40,171 fractions (fractions unavailable for 1,225 cobalt patients), of which 6,244 (15.5%) were adapted. Thirteen centers (81.3%) had treated for > = 1 year, of which 9 treated > 100 patients/year and 6 treated > 150 patients/year. Ultra-hypofractionation (1-5 fractions) was delivered for 72.9% of all patients. The proportion of fractions adapted in patients receiving ultra-hypofractionation was 28.6%, with an average of 3.2 adapted fractions per course. The most commonly treated tumor types were pancreas (20.7%), liver (16.5%), prostate (12.5%), breast (11.5%), and lung (9.4%), respectively, with significantly increased number of fractions delivered from 2018-2020 compared to 2014-2017 for each (pancreas: 5,161 vs. 1,155; liver: 3,597 vs. 921; prostate: 5,795 vs. 1,398; breast: 2,221 vs. 1,876; lung: 2,589 vs. 660). The compound annual growth rate (CAGR) in the number of patients was 59.5%, growing from 111 in 2014 to 1,830 in 2020. Ultra-hypofractionation increased from 31.8% of all treated MR-Linac patients in 2014 to 87.0% in 2020 (n = 1,576/1,811). The proportion of adapted fractions in all patients and ultra-hypofractionation patients increased from 0% in the first two years to 24.3% (n = 3,071/12,639) and 33.8% (n = 2,677/7,911) respectively, by the end of 2020. No patient had adaptive treatment in 2014 although adaptive replanning steadily increased over time. For example, in 2020 vs. 2018 the proportion of adaptive fractions was highest for pancreas (60.6% vs. 50.8%), liver (17.8% vs. 9.9%), and lung (17.8% vs. 1.8%) cancers. This is the first comprehensive study reporting patterns of utilization among early adopters of a 0.35T-MRgRT system in the US. Intrafraction MR guidance, advanced motion management, and increasing adoption of adaptive RT has accelerated a transition to ultra-hypofractionation regimens. MRgRT has been predominantly used to treat abdominal and pelvic tumors, and increasingly with adaptive replanning, which is a radical departure from legacy radiotherapy practices

Sulphur-functionalized graphene towards high performance supercapacitor

10.1016/j.nanoen.2014.12.030Nano Energy12250-25

Hepatic cystogenesis is associated with abnormal expression and location of ion transporters and water channels in an animal model of autosomal recessive polycystic kidney disease

Polycystic kidney (PCK) rats are a spontaneous model of autosomal recessive polycystic kidney disease that exhibit cholangiocyte-derived liver cysts. We have previously reported that in normal cholangiocytes a subset of vesicles contain three proteins (ie, the water channel AQP1, the chloride channel CFTR, and the anion exchanger AE2) that account for ion-driven water transport. Thus, we hypothesized that altered expression and location of these functionally related proteins contribute to hepatic cystogenesis. We show here that under basal conditions and in response to secretin and hypotonicity, cysts from PCK rats expanded to a greater degree than cysts formed by normal bile ducts. Quantitative reverse transcriptase-polymerase chain reaction, immunoblot analysis, and confocal and immunoelectron microscopy all indicated increased expression of these three proteins in PCK cholangiocytes versus normal cholangiocytes. AQP1, CFTR, and AE2 were localized preferentially to the apical membrane in normal rats while overexpressed at the basolateral membrane in PCK rats. Exposure of the cholangiocyte basolateral membrane to CFTR inhibitors [5-nitro-2-(3-phenylpropylamino)-benzoic acid and CFTRinh172], or Cl(-)/HCO(3)(-) exchange inhibitors (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate and 4-acetamido-4'-isothiocyanato-2,2'-stilbenedisulfonic acid disodium salt hydrate) blocked secretin-stimulated fluid accumulation in PCK but not in normal cysts. Our data suggest that hepatic cystogenesis in autosomal recessive polycystic kidney disease may involve increased fluid accumulation because of overexpression and abnormal location of AQP1, CFTR, and AE2 in cystic cholangiocytes. Therapeutic interventions that block the activation of these proteins might inhibit cyst expansion in polycystic liver disease

O extrato de maracujá sobre a morfometria de hepatócitos da tilápia do Nilo The passion fruit on hepatocytes morphometry of Nile tilapia

Avaliaram-se os efeitos do extrato de maracujá veiculado na dieta (0, 50, 100 e 200mg kg-1) sobre o consumo de alimento, o ganho em peso e os níveis de glicose e cortisol plasmático de juvenis de tilápias do Nilo (87,0&plusmn;6,6g). Ao final do experimento (28 dias), os peixes foram eutanasiados para remoção do fígado, visando à avaliação da área citoplasmática, contagem de células e verificação dos estoques de glicogênio hepático. Os dados foram submetidos à ANOVA unidirecional, comparando-se as médias pelo Teste de Tukey (P<0,05), com posterior estudo de regressão, buscando estabelecer as curvas das áreas citoplasmáticas, em função das diferentes doses do extrato. A inclusão do extrato na dieta não afetou o consumo de alimento e o crescimento e todos os peixes apresentaram aumento da glicose e redução do cortisol plasmático, porém sem diferenças entre os tratamentos. As curvas de regressão indicaram aumento quadrático da área citoplasmática com a elevação da doses do extrato, principalmente para 100mg kg-1, resultando em uma curva dose-resposta em forma de "U" invertido. O aumento da área do citoplasma decorreu de um acúmulo de glicogênio hepático, conforme comprovado pela prova da amilase salivar. Concluiu-se que o extrato de maracujá pode ser fornecido na dieta de juvenis de tilápia, sem prejudicar o consumo alimentar e o crescimento dos animais e que o produto altera a morfometria dos hepatócitos, sugerindo a atividade de flavonóides sobre o metabolismo de carboidratos.<br>The effects of passion fruit extract (0, 50, 100 and 200mg kg-1) on food consumption, growth and glucose levels and plasma cortisol were investigated in juvenile Nile tilapia (87.0&plusmn;6.6g). After 28 days, fish were killed and the liver was removed for study of cytoplasm area, cell count and verification of hepatic glycogen stores. The data were subjected to one-way ANOVA comparing the means by Tukey&acute;s test (P<0.05), with further study to establish the regression curves of cytoplasm areas related to different doses of the extract. The inclusion of the extract in the diet did not affect food consumption and growth, and all fish showed increased glucose and reduced plasma cortisol, without differences between treatments. The cytoplasm area increased quadratically as the doses increased, mainly for 100mg kg-1, resulting in an inverted "U" dose-response curve. The increase of cytoplasm area resulted from hepatic glycogen storage, as confirmed by salivary amylase. It was concluded that passion fruit extract can be delivered in the diet of juvenile tilapia, without impairing of food consumption and growth, and that the product affects the hepatocytes morphometry, suggesting flavonoids activity on carbohydrate metabolism