Magnetic diagnostics using the third-harmonic magnetic response for a molecule-based magnet networked by a single chiral ligand

We investigated complex magnetic domain formation on a chiral molecule-based magnet, [Cr(CN)6][Mn(R)-pnH(H2O)](H2O) (termed as R-GN), whose two-dimensional molecular network was constructed with the help of a single-handed chiral ligand ((R)-pn). There, the first- and third-harmonic magnetic responses (M1ω and M3ω) against the ac magnetic field were observed, and magnetic hysteresis in ac field of a few Oe was discussed in terms of Rayleigh loop. The diagnostics of this magnetic hysteresis clarified the complex process of magnetic domain formation against a change in temperature. For R-GN, it was reported that a giant M3ω (termed #4 in this paper) appeared just above the so-called “magnetic ordering temperature (TC)." In the present study, three M3ω responses (#1-3) were newly observed on the lower-temperature side of #4, and the ac field dependencies for all of #1-#4 were investigated. #1 also accompanied the giant M3ω, which suggests that a significant degree of magnetic fluctuation surviving below TC. This glassy behavior below TC is an attractive new phenomenon in molecule-based magnets with a single-handed chiral ligand. #2 and #3 exhibited magnetic ordering and the formation of a small magnetic domain, respectively. The M3ω responses of #1-3 were suppressed with increasing the amplitude of ac field, and the corresponding magnetic hysteresis was a normal Rayleigh loop accompanying the out-of-phase of the M1ω response. The M3ω response of #4 without the out-of-phase of M1ω was, however, enhanced with increasing the amplitude of ac field, and #4 represented a large magnetic hysteresis in the paramagnetic region, intrinsically different from those of #1-#3

Effect of sitagliptin on the echocardiographic parameters of left ventricular diastolic function in patients with type 2 diabetes : a subgroup analysis of the PROLOGUE study

Background: Diabetes is associated closely with an increased risk of cardiovascular events, including diastolic dysfunction and heart failure that leads to a shortening of life expectancy. It is therefore extremely valuable to evaluate the impact of antidiabetic agents on cardiac function. However, the influence of dipeptidyl peptidase 4 inhibitors on cardiac function is controversial and a major matter of clinical concern. We therefore evaluated the effect of sitagliptin on echocardiographic parameters of diastolic function in patients with type 2 diabetes as a sub-analysis of the PROLOGUE study. Methods: Patients in the PROLOGUE study were assigned randomly to either add-on sitagliptin treatment or conventional antidiabetic treatment. Of the 463 patients in the overall study, 115 patients (55 in the sitagliptin group and 60 in the conventional group) who had complete echocardiographic data of the ratio of peak early diastolic transmitral flow velocity (E) to peak early diastolic mitral annular velocity (e′) at baseline and after 12 and 24 months were included in this study. The primary endpoint of this post hoc sub-analysis was a comparison of the changes in the ratio of E to e′ (E/e′) between the two groups from baseline to 24 months. Results: The baseline-adjusted change in E/e′ during 24 months was significantly lower in the sitagliptin group than in the conventional group (−0.18 ± 0.55 vs. 1.91 ± 0.53, p = 0.008), irrespective of a higher E/e′ value at baseline in the sitagliptin group. In analysis of covariance, sitagliptin treatment was significantly associated with change in E/e′ over 24 months (β = −9.959, p = 0.001), independent of other clinical variables at baseline such as blood pressure, HbA1c, and medications for diabetes. Changes in other clinical variables including blood pressure and glycemic parameters, and echocardiographic parameters, such as cardiac structure and systolic function, were comparable between the two groups. There was also no significant difference in the serum levels of N-terminal-pro brain natriuretic peptide and high-sensitive C-reactive protein between the two groups during the study period. Conclusions: Adding sitagliptin to conventional antidiabetic regimens in patients with T2DM for 24 months attenuated the annual exacerbation in the echocardiographic parameter of diastolic dysfunction (E/e′) independent of other clinical variables such as blood pressure and glycemic control

Observation of domain wall bimerons in chiral magnets

Topological defects embedded in or combined with domain walls have been proposed in various systems, some of which are referred to as domain wall skyrmions or domain wall bimerons. However, the experimental observation of such topological defects remains an ongoing challenge. Here, using Lorentz transmission electron microscopy, we report the experimental discovery of domain wall bimerons in chiral magnet Co-Zn-Mn(110) thin films. By applying a magnetic field, multidomain structures develop, and simultaneously, chained and isolated bimerons arise as the localized state between the domains with the opposite in-plane components of net magnetization. The multidomain formation is attributed to magnetic anisotropy and dipolar interaction, and domain wall bimerons are stabilized by the Dzyaloshinskii-Moriya interaction. In addition, micromagnetic simulations show that domain wall bimerons appear for a wide range of conditions in chiral magnets with cubic magnetic anisotropy. Our results promote further study in various fields of physics.Comment: 30 pages, 10 figures (including Supplementary Materials

Monitoring of Crystallization Process in Solution-Processed Pentacene Thin Films by Chemical Conversion Reactions

Solution-processable organic semiconductors having bulky substituent groups on the π-conjugated skeleton are rapidly gaining attention for their potential applications to large-area electronics. While the substituent groups contribute to the good solubility in organic solvents, they give rise to hopping sites in a thin film, affecting adversely the charge-carrier transport. As an alternative material, a solvent-soluble precursor compound with thermally cleavable functional groups is promising, which can be converted by heat treatment into a thin film to generate the desired material consisting solely of conjugated systems. This precursor approach is practically applied to various thin-film-based devices. The overall process of the thin film growth, however, remains unrevealed. In the present study, solution-processed pentacene thin films are prepared from a thermally convertible precursor, and the structural evolution during the chemical conversion reaction has been revealed by a combination of cutting-edge analytical tools of two-dimensional X-ray diffraction (2D-GIXD) and p-polarized multiple-angle incidence resolution spectrometry (pMAIRS). The highlight is that pentacene is crystallized in a stepwise manner in the thermally converted films, which is substantially different from a typical growth process. In addition, influences of the oxidation reaction of pentacene on the molecular arrangement are also discussed quantitatively. This study provides a fundamental schematic of thin films grown by the precursor method

High-pressure xenon gas time projection chamber with scalable design and its performance at around the Q value of 136^{136}Xe double-beta decay

We have been developing a high-pressure xenon gas time projection chamber (TPC) to search for neutrinoless double beta ($0\nu\beta\beta$) decay of $^{136}$Xe. The unique feature of this TPC is in the detection part of ionization electrons, called ELCC. ELCC is composed of multiple units, and one unit covers 48.5 $\mathrm{cm}^2$. A 180 L size prototype detector with 12 units, 672 channels, of ELCC was constructed and operated with 7.6 bar natural xenon gas to evaluate the performance of the detector at around the Q value of $^{136}$Xe $0\nu\beta\beta$. The obtained FWHM energy resolution is (0.73 $\pm$ 0.11) % at 1836 keV. This corresponds to (0.60 $\pm$ 0.03) % to (0.70 $\pm$ 0.21) % of energy resolution at the Q value of $^{136}Xe$ $0\nu\beta\beta$. This result shows the scalability of the AXEL detector with ELCC while maintaining high energy resolution. Factors determining the energy resolution were quantitatively evaluated and the result indicates further improvement is feasible. Reconstructed track images show distinctive structures at the endpoint of electron tracks, which will be an important feature to distinguish $0\nu\beta\beta$ signals from gamma-ray backgrounds.Comment: 33 pages, 24 figures, preprint accepted by PTE

Plasmodium berghei Circumvents Immune Responses Induced by Merozoite Surface Protein 1- and Apical Membrane Antigen 1-Based Vaccines

BACKGROUND: Two current leading malaria blood-stage vaccine candidate antigens for Plasmodium falciparum, the C-terminal region of merozoite surface protein 1 (MSP1(19)) and apical membrane antigen 1 (AMA1), have been prioritized because of outstanding protective efficacies achieved in a rodent malaria Plasmodium yoelii model. However, P. falciparum vaccines based on these antigens have had disappointing outcomes in clinical trials. Discrepancies in the vaccine efficacies observed between the P. yoelii model and human clinical trials still remain problematic. METHODOLOGY AND RESULTS: In this study, we assessed the protective efficacies of a series of MSP1(19)- and AMA1-based vaccines using the P. berghei rodent malarial parasite and its transgenic models. Immunization of mice with a baculoviral-based vaccine (BBV) expressing P. falciparum MSP1(19) induced high titers of PfMSP1(19)-specific antibodies that strongly reacted with P. falciparum blood-stage parasites. However, no protection was achieved following lethal challenge with transgenic P. berghei expressing PfMSP1(19) in place of native PbMSP1(19). Similarly, neither P. berghei MSP1(19)- nor AMA1-BBV was effective against P. berghei. In contrast, immunization with P. yoelii MSP1(19)- and AMA1-BBVs provided 100% and 40% protection, respectively, against P. yoelii lethal challenge. Mice that naturally acquired sterile immunity against P. berghei became cross-resistant to P. yoelii, but not vice versa. CONCLUSION: This is the first study to address blood-stage vaccine efficacies using both P. berghei and P. yoelii models at the same time. P. berghei completely circumvents immune responses induced by MSP1(19)- and AMA1-based vaccines, suggesting that P. berghei possesses additional molecules and/or mechanisms that circumvent the host's immune responses to MSP1(19) and AMA1, which are lacking in P. yoelii. Although it is not known whether P. falciparum shares these escape mechanisms with P. berghei, P. berghei and its transgenic models may have potential as useful tools for identifying and evaluating new blood-stage vaccine candidate antigens for P. falciparum

Gastric variceal bleeding caused by an intrahepatic arterioportal fistula that formed after liver biopsy: a case report and review of the literature

An intrahepatic arterioportal fistula is a rare cause of portal hypertension and variceal bleeding. We report on a patient with an intrahepatic arterioportal fistula following liver biopsy who was successfully treated by hepatectomy after unsuccessful arterial embolization. We also review the literature on symptomatic intrahepatic arterioportal fistulas after liver biopsy. A 48-year-old male with bleeding gastric varices and hepatitis B virus-associated liver cirrhosis was transferred to our hospital; this patient previously underwent percutaneous liver biopsies 3 and 6 years ago. Abdominal examination revealed a bruit over the liver, tenderness in the right upper quadrant, and splenomegaly. Ultrasonographic examination, computed tomography, and angiography confirmed an arterioportal fistula between the right hepatic artery and the right portal vein with portal hypertension. After admission, the patient suffered a large hematemesis and developed shock. He was treated with emergency transarterial embolization using microcoils. Since some collateral vessels bypassed the obstructive coils and still fed the fistulous area, embolization was performed again. Despite the second embolization, the collateral vessels could not be completely controlled. Radical treatment involving resection of his right hepatic lobe was performed. For nearly 6 years postoperatively, this patient has had no further episodes of variceal bleeding