Supercapacitor Sizing for Fast Power Dips in a Hybrid Supercapacitor—PEM Fuel Cell System

Polymer electrolyte membrane fuel cell (PEM FC) operation is likely to be characterized by voltage dips on timescales shorter than 1 s, arising from temporary flooding of gas channels or porous layers, particularly when the FC is operated at high humidity levels. If supercapacitors are employed in hybrid systems, they can make up for the temporary lack of energy produced by the FC. However, the steep slopes of the voltage dips affect the energy that can be actually delivered by the supercapacitor because of its series impedance, and this should be taken into account when sizing it. This paper presents a simplified approach for sizing the supercapacitor, based on some observed peculiar features of the FC dips, which allow a simple but accurate model for the evaluation of the supercapacitor response to such dips. The validity of such an approach is supported by simulation and experimental results performed on a single PEM FC and on a supercapacitor

Tumor-infiltrating lymphocytes and breast cancer: Beyond the prognostic and predictive utility

The importance of the immune system as a potent anti-tumor defense has been consolidated in recent times, and novel immune-related therapies are today demonstrating a strong clinical benefit in the setting of several solid neoplasms. Tumor-infiltrating lymphocytes reflect the attempt of the host to eradicate malignancies, and during the last decades, they have been shown to possess an interesting prognostic utility for breast cancer, especially in case of HER2 positive and triple-negative molecular subtypes. In parallel, the clinical evaluation of tumor-infiltrating lymphocytes has been shown to effectively predict treatment outcomes in both neoadjuvant and adjuvant settings. Currently, tumor-infiltrating lymphocytes are promising further predictive utility in view of novel immune-related therapeutic strategies which are coming into the clinical setting launching a solid rationale for the future next-generation treatment options. In this scenario, tumor-infiltrating lymphocytes might represent an important resource for the selection of the most appropriate therapeutic strategy, as well as further evaluations of the molecular mechanisms underlying tumor-infiltrating lymphocytes and the immunoediting process would eventually provide new insights to augment therapeutic success. Considering these perspectives, we review the potential utility of tumor-infiltrating lymphocytes in the definition of breast cancer prognosis and in the prediction of treatment outcomes, along with the new promising molecular-based therapeutic discoverie

The dependence of dijet production on photon virtuality in ep collisions at HERA

The dependence of dijet production on the virtuality of the exchanged photon, Q^2, has been studied by measuring dijet cross sections in the range 0 < Q^2 < 2000 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb^-1. Dijet cross sections were measured for jets with transverse energy E_T^jet > 7.5 and 6.5 GeV and pseudorapidities in the photon-proton centre-of-mass frame in the range -3 < eta^jet <0. The variable xg^obs, a measure of the photon momentum entering the hard process, was used to enhance the sensitivity of the measurement to the photon structure. The Q^2 dependence of the ratio of low- to high-xg^obs events was measured. Next-to-leading-order QCD predictions were found to generally underestimate the low-xg^obs contribution relative to that at high xg^obs. Monte Carlo models based on leading-logarithmic parton-showers, using a partonic structure for the photon which falls smoothly with increasing Q^2, provide a qualitative description of the data.Comment: 35 pages, 6 eps figures, submitted to Eur.Phys.J.

Beauty photoproduction measured using decays into muons in dijet events in ep collisions at s\sqrt{s}=318 GeV

The photoproduction of beauty quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb$^{- 1}$. The fraction of jets containing b quarks was extracted from the transverse momentum distribution of the muon relative to the closest jet. Differential cross sections for beauty production as a function of the transverse momentum and pseudorapidity of the muon, of the associated jet and of $x_{\gamma}^{jets}$, the fraction of the photon's momentum participating in the hard process, are compared with MC models and QCD predictions made at next-to-leading order. The latter give a good description of the data.Comment: 32 pages, 6 tables, 7 figures Table 6 and Figure 7 revised September 200

Search for a narrow charmed baryonic state decaying to D^*+/- p^-/+ in ep collisions at HERA

A resonance search has been made in the D^*+/- p^-/+ invariant-mass spectrum with the ZEUS detector at HERA using an integrated luminosity of 126 pb^-1. The decay channels D^*+ -> D^0 pi^+_s -> (K^- pi^+) pi^+_s and D^*+ -> D^0 pi^+_s -> (K^- pi^+ pi^+ pi^-) pi^+_s (and the corresponding antiparticle decays) were used to identify D^*+/- mesons. No resonance structure was observed in the D^*+/- p^-/+ mass spectrum from more than 60000 reconstructed D^*+/- mesons. The results are not compatible with a report of the H1 Collaboration of a charmed pentaquark, Theta^0_c.Comment: 22 pages, 7 figures, 1 table; minor text revisions; 2 references adde

Endometriosis and Headache

Headache and endometriosis show some similarities in their clinical and epidemiological features that are probably due to the influence of female sexual hormones on both disorders. Epidemiological studies indicate that they are comorbid disorders. However, the nature of the comorbidity is not known with certainty, but a likely explanation may be common susceptibility genes. Another possibility is that, because they both are related to pain, increased pain sensitivity induced by one of the disorders may lead to a higher likelihood of developing the other, possibly mediated by nitrogen oxide or prostaglandins. A common link to the widespread use of estroprogestins may seem less probable. For physicians dealing with women with either of these disorders, awareness of the comorbidity may be helpful in the treatment of the patient

Elastically driven, intermittent microscopic dynamics in soft solids

Soft solids with tunable mechanical response are at the core of new material technologies, but a crucial limit for applications is their progressive aging over time, which dramatically affects their functionalities. The generally accepted paradigm is that such aging is gradual and its origin is in slower than exponential microscopic dynamics, akin to the ones in supercooled liquids or glasses. Nevertheless, time- and space-resolved measurements have provided contrasting evidence: dynamics faster than exponential, intermittency, and abrupt structural changes. Here we use 3D computer simulations of a microscopic model to reveal that the timescales governing stress relaxation respectively through thermal fluctuations and elastic recovery are key for the aging dynamics. When thermal fluctuations are too weak, stress heterogeneities frozen-in upon solidification can still partially relax through elastically driven fluctuations. Such fluctuations are intermittent, because of strong correlations that persist over the timescale of experiments or simulations, leading to faster than exponential dynamics.Comment: 7 pages, Supplementary Information include

Antiproton slowing Down in H2 and He and evidence of nuclear stopping power

We report stopping powers of hydrogen and helium for antiprotons of kinetic energies ranging from about 0.5 keV to 1.1 MeV. The Barkas effect, i.e., a difference in the stopping power for antiprotons and protons of the same energy in the same material, shows up clearly in either of the gases. Moreover, below ≈0.5 keV there is indirect evidence for an increase of the antiproton stopping power. This "nuclear" effect, i.e., energy losses in quasimolecular interactions, shows up in fair agreement with theoretical predictions

Modulation of 11β-hydroxysteroid dehydrogenase as a strategy to reduce vascular inflammation

Atherosclerosis is a chronic inflammatory disease in which initial vascular damage leads to extensive macrophage and lymphocyte infiltration. Although acutely glucocorticoids suppress inflammation, chronic glucocorticoid excess worsens atherosclerosis, possibly by exacerbating systemic cardiovascular risk factors. However, glucocorticoid action within the lesion may reduce neointimal proliferation and inflammation. Glucocorticoid levels within cells do not necessarily reflect circulating levels due to pre-receptor metabolism by 11β-hydroxysteroid dehydrogenases (11β-HSDs). 11β-HSD2 converts active glucocorticoids into inert 11-keto forms. 11β-HSD1 catalyses the reverse reaction, regenerating active glucocorticoids. 11β-HSD2-deficiency/ inhibition causes hypertension, whereas deficiency/ inhibition of 11β-HSD1 generates a cardioprotective lipid profile and improves glycemic control. Importantly, 11β-HSD1-deficiency/ inhibition is atheroprotective, whereas 11β-HSD2-deficiency accelerates atherosclerosis. These effects are largely independent of systemic risk factors, reflecting modulation of glucocorticoid action and inflammation within the vasculature. Here, we consider whether evidence linking the 11β-HSDs to vascular inflammation suggests these isozymes are potential therapeutic targets in vascular injury and atherosclerosis