Magnetic‐nanoparticle‐mediated intracellular hyperthermia has the potential to achieve localized tumor heating without any side effects. The technique consists of targeting magnetic nanoparticles to ...tumor tissue followed by application of an external alternating magnetic field that induces heat through Néel relaxation loss of the magnetic nanoparticles. The temperature in tumor tissue is increased to above 43°C, which causes necrosis of cancer cells, but does not damage surrounding normal tissue. Among magnetic nanoparticles available, magnetite has been extensively studied. Recent years have seen remarkable advances in magnetite‐nanoparticle‐mediated hyperthermia; both functional magnetite nanoparticles and alternating‐magnetic‐field generators have been developed. In addition to the expected tumor cell death, hyperthermia treatment has also induced unexpected biological responses, such as tumor‐specific immune responses as a result of heat‐shock protein expression. These results suggest that hyperthermia is able to kill not only local tumors exposed to heat treatment, but also tumors at distant sites, including metastatic cancer cells. Currently, several research centers have begun clinical trials with promising results, suggesting that the time may have come for clinical applications. This review describes recent advances in magnetite nanoparticle‐mediated hyperthermia.
We explore cosmological magnetogenesis in the post-inflationary universe, when the inflaton oscillates around its potential minimum and the universe is effectively dominated by cold matter. During ...this epoch prior to reheating, large-scale magnetic fields can be significantly produced by the cosmological background. By considering magnetogenesis both during and after inflation, we demonstrate that magnetic fields stronger than 10 super(-15) G can be generated on Mpc scales without having strong couplings in the theory, or producing too large electric fields that would dominate the universe.
A
bstract
We investigate pair creation by an electric field in four-dimensional de Sitter space. The expectation value of the induced current is computed, using the method of adiabatic ...regularization. Under strong electric fields the behavior of the current is similar to that in flat space, while under weak electric fields the current becomes inversely proportional to the mass squared of the charged field. Thus we find that the de Sitter space obtains a large conductivity under weak electric fields in the presence of a charged field with a tiny mass. We then apply the results to constrain electromagnetic fields in the early universe. In particular, we study cosmological scenarios for generating large-scale magnetic fields during the inflationary era. Electric fields generated along with the magnetic fields can induce sufficiently large conductivity to terminate the phase of magnetogenesis. For inflationary magnetogenesis models with a modified Maxwell kinetic term, the generated magnetic fields cannot exceed 10
−30
G on Mpc scales in the present epoch, when a charged field carrying an elementary charge with mass of order the Hubble scale or smaller exists in the Lagrangian. Similar constraints from the Schwinger effect apply for other magnetogenesis mechanisms.
It is usually assumed that when Weyl invariance is unbroken in the electromagnetic sector, the energy density of primordial magnetic fields will redshift as radiation. Here we show that primordial ...magnetic fields do not exhibit radiationlike redshifting in the presence of stronger electric fields, as a consequence of Faraday's law of induction. In particular for the standard Maxwell theory, magnetic fields on superhorizon scales can redshift as B2∝a−6H−2, instead of the usually assumed a−4. Taking into account this effect for inflationary magnetogenesis can correct previous estimates of the magnetic field strength by up to 37 orders of magnitude. This opens new possibilities for inflationary magnetogenesis, and as an example we propose a scenario where femto-Gauss intergalactic magnetic fields are created on Mpc scales, with high-scale inflation producing observable primordial gravitational waves, and reheating happening at low temperatures.
A model composed of a transmission-line structure with a Randles-type circuit is regarded as a useful model for lithium-ion battery electrodes. However, when used for the impedance fitting analyses, ...the parameters needed to be given for calculations, the parameters to be practically obtained, and the accuracy of the obtained values have not been clarified yet. Herein, we reveal that parameters in this model can practically be obtained simultaneously from the impedance fitting calculations when the values of transmission-line length and diffusion length are provided. Then, their accuracy is investigated by examining the correlations between the parameters in the fitting calculations.
The COVID-19 pandemic has created urgent demand for rapid detection of the SARS-CoV-2 coronavirus. Herein, we report highly sensitive detection of SARS-CoV-2 nucleocapsid protein (N protein) using ...nanoparticle-enhanced surface plasmon resonance (SPR) techniques. A crucial plasmonic role in significantly enhancing the limit of detection (LOD) is revealed for exceptionally large gold nanoparticles (AuNPs) with diameters of hundreds of nm. SPR enhanced by these large nanoparticles lowered the LOD of SARS-CoV-2 N protein to 85 fM, resulting in the highest SPR detection sensitivity ever obtained for SARS-CoV-2 N protein.
All-solid-state sodium (Na) batteries are attracting attention as alternative systems to lithium-ion batteries because of the high abundance and safety of Na. Although inorganic solid electrolytes ...have mainly been investigated because of their high ionic conductivity, such electrolytes show low interfacial stability with electrodes in bulk-type all-solid-state batteries. Compared with inorganic solid electrolytes, solid polymer electrolytes show high formability at electrode/electrolyte interfaces and relatively low ionic conductivity. To improve the ionic conductivity and mechanical properties of polymer electrolytes, addition of inorganic powder has been broadly investigated. However, few composite electrolytes of a polymer and Na-conductive inorganic electrolyte with a high content of inorganic electrolyte have been reported. In this study, composite solid electrolytes (CSEs) of a polyether-based polymer and inorganic Na3Zr2Si2PO12 (NZSP) were prepared to utilize the advantages of both materials. The prepared CSEs exhibited increasing ionic conductivity with decreasing NZSP ratio (<50 wt %). Differential scanning calorimetry and Fourier transform infrared spectroscopy analyses indicated that this behavior was caused by the improved segmental mobility of polyether at low NZSP content, which promoted dissociation of the NaTFSA salt. Conversely, CSEs with a high NZSP ratio showed decreased ionic conductivity because the aggregation of NZSP particles increased grain boundary resistance. With a Na metal electrode, the CSE with a high NZSP content (200 wt %) showed lower interfacial resistance and apparent activation energy compared with those of the NZSP-free system. The Na+ transference number of the CSEs was highest for that with a high NZSP content of 200 wt %. Higher NZSP content is therefore expected to realize faster charge transfer during the charge–discharge process than a lower NZSP content. All-solid-state Na–NaCoO2 and Na–sulfur batteries containing the CSE with 200 wt % NZSP operated at 333 K with capacities of 115 and 170 mAh g–1, respectively.
This study extracts the common factors from firm-based credit spreads of major Japanese corporate bonds and examines the predictive content of the credit spread on the real economy. Instead of ...employing single-maturity corporate bond spreads, we focus on the entire term structure of the credit spread to predict the business cycle. We extend the dynamic Nelson-Siegel model to allow for both common and firm-specific factors. The results show that the estimated common factors are important drivers of individual credit spreads and have substantial predictive power for future Japanese economic activity. This study contributes to the literature by examining the relationship between firm-based credit spread curves and economic fluctuation and forecasting the business cycle.
Inflaxion dark matter Kobayashi, Takeshi; Ubaldi, Lorenzo
The journal of high energy physics,
08/2019, Letnik:
2019, Številka:
8
Journal Article
Recenzirano
Odprti dostop
A
bstract
A new mechanism for producing axion dark matter is proposed. By invoking low-scale inflation and a kinetic mixing between the axion and the inflaton, it is shown that the axion is driven to ...a field point slightly displaced from the potential minimum, which can give rise to the observed dark matter abundance. In this framework, different combinations of the axion and inflaton fields play various cosmological roles, including generating the cosmological perturbations, reheating the universe, and serving as dark matter. The kinetic mixing also relates the dark matter lifetime with the reheating temperature. The mechanism tames axions that would otherwise overdominate the universe, and thus opens up new windows in the axion parameter space, including decay constants at the GUT scale and higher.
A heterodinuclear iridium−ruthenium complex IrIII(Cp*)(H2O)(bpm)RuII(bpy)2(SO4)2 {1(SO4)2, Cp* = η5-pentamethylcyclopentadienyl, bpm = 2,2′-bipyrimidine, bpy = 2,2′-bipyridine} acts as the most ...effective catalyst for selective production of hydrogen from formic acid in an aqueous solution at ambient temperature among catalysts reported so far. An unusually large tunneling effect was observed for the first time for the catalytic hydrogen production in H2O vs D2O.
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