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We investigated the magnetoelectric properties of Cr2O3/Co all-thin-film exchange coupling system with Cr spacer layer. In this system, significantly small coercivity (Hc<50Oe) was obtained by the Cr spacer layer insertion between Cr2O3 and Co layers. Owing to the small Hc, exchange bias field, Hex, larger than Hc was achieved. It enabled us to observe magnetization switching at a zero magnetic field, when Hex was reversed by magnetoelectric effect of Cr2O3 layer. Finally, we demonstrated the isothermal magnetoelectric switching of magnetization in the Cr2O3/Cr/Co all-thin-film system. By changing the direction of the electric field during the isothermal magnetoelectric switching process, both Hex and magnetization at a zero magnetic field were reversed back and forth, i.e., isothermal magnetization switching by an electric field was achieved. [ABSTRACT FROM AUTHOR]

We investigated the effect of Pt insertion on a Cr2O3/Co exchange coupling system. The perpendicular exchange bias μ0Hex decreased with increasing Pt insertion layer thickness, and we observed positive μ0Hex for samples with relatively thick Pt insertion layers. We also examined the cooling field μ0Hfc dependence of μ0Hex for the samples. At small μ0Hfc, all samples exhibited negative μ0Hex. With increasing μ0Hfc, a shift of μ0Hex from negative to positive was observed. In the past, similar behaviors were observed for FeF2/Fe systems exhibiting positive μ0Hex. In addition, the μ0Hfc dependence of μ0Hex was well fitted by an equation taking into account the Zeeman energy at the surface of an antiferromagnet as well as an antiferromagnetic exchange coupling. The results strongly suggest that (1) Cr2O3 surface spin is affected by the external magnetic field and (2) the coupling at the Cr2O3/Pt/Co interface is antiferromagnetic. [ABSTRACT FROM AUTHOR]

We investigate the magnetic, electric, and magnetoelectric properties of a Cr2O3 thin film system that was deposited by radiofrequency magnetron sputtering. The temperature dependence of the magnetic susceptibility of our Cr2O3 film is similar to that of bulk Cr2O3, which indicates a small oxygen non-stoichiometry in the film. The Cr2O3 film exhibits high AC resistivity (∼109 Ωcm) and low leakage current (4.0×10-5 A/cm2 at E=80 kV/cm). Finally, we demonstrate magnetoelectric switching of the exchange bias using the Cr2O3/Pt/Co all-thin-film system. By changing the direction of the electric field during the magnetoelectric field cooling process, the exchange bias field was changed symmetrically from -160 Oe to +160 Oe, which represents the switching of the antiferromagnetic domain of Cr2O3. [ABSTRACT FROM AUTHOR]

Risk factors for pacemaker-induced cardiomyopathy (PICM) have been previously reported, including a high burden of right ventricular pacing, lower left ventricular ejection fraction, a wide QRS duration, and left bundle branch block before pacemaker implantation (PMI). However, predicting the development of PICM remains challenging. This study aimed to use a convolutional neural network (CNN) model, based on clinical findings before PMI, to predict the development of PICM. Out of a total of 561 patients with dual-chamber PMI, 165 (mean age 71.6 years, 89 men [53.9%]) who underwent echocardiography both before and after dual-chamber PMI were enrolled. During a mean follow-up period of 1.7 years, 47 patients developed PICM. A CNN algorithm for prediction of the development of PICM was constructed based on a dataset prior to PMI that included 31 variables such as age, sex, body mass index, left ventricular ejection fraction, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left atrial diameter, severity of mitral regurgitation, severity of tricuspid regurgitation, ischemic heart disease, diabetes mellitus, hypertension, heart failure, New York Heart Association class, atrial fibrillation, the etiology of bradycardia (sick sinus syndrome or atrioventricular block) , right ventricular (RV) lead tip position (apex, septum, left bundle, His bundle, RV outflow tract), left bundle branch block, QRS duration, white blood cell count, haemoglobin, platelet count, serum total protein, albumin, aspartate transaminase, alanine transaminase, estimated glomerular filtration rate, sodium, potassium, C-reactive protein, and brain natriuretic peptide. The accuracy, sensitivity, specificity, and area under the curve of the CNN model were 75.8%, 55.6%, 83.3% and 0.78 respectively. The CNN model could accurately predict the development of PICM using clinical findings before PMI. This model could be useful for screening patients at risk of developing PICM, ensuring timely upgrades to physiological pacing to avoid missing the optimal intervention window., (© 2024. The Author(s).)

Clinical predictors for pacemaker-induced cardiomyopathy (PICM) (e.g., a wide QRS duration and left bundle branch block at baseline) have been reported. However, factors involved in the development of PICM in patients with preserved left ventricular ejection fraction (LVEF) remain unknown. This study aimed to determine the risk factors for PICM in patients with preserved LVEF. The data of 113 patients (average age: 71.3 years; men: 54.9%) who had echocardiography before and after pacemaker implantation (PMI) among 465 patients undergoing dual-chamber PMI were retrospectively analyzed. Thirty-three patients were diagnosed with PICM (18.0/100 person-years; 95% CI 12.8-25.2). A univariate Cox regression analysis showed that an estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m 2 (HR 3.47; 95% CI 1.48-8.16) and a past medical history of coronary artery disease (CAD) (HR 2.76; 95% CI 1.36-5.60) were significantly associated with the onset of PICM. After adjusting for clinical variables, an eGFR ≤ 30 mL/min/1.73 m 2 (HR 2.62; 95% CI 1.09-6.29) and a medical history of CAD (HR 2.32; 95% CI 1.13-4.80) were independent risk factors for developing PICM. A medical history of CAD and low eGFR are independent risk factors for PICM in patients with preserved LVEF at baseline. These results could be helpful in predicting a decreased LVEF by ventricular pacing before PMI. Close follow-up by echocardiography is recommended to avoid a delay in upgrading to physiological pacing, such as cardiac resynchronization therapy or conduction system pacing., (© 2023. Springer Nature Limited.)

Background: Ischemic stroke (IS) and major bleeding, which are serious adverse events in patients with atrial fibrillation (AF), could have seasonal variations, but there are few reports.Methods and Results:In the Shinken Database 2004-2016 (n=22,018), 3,581 AF patients (average age, 63.5 years; 2,656 men, 74.2%; 1,388 persistent AF, 38.8%) were identified. Median CHADS 2 and HAS-BLED scores were both 1 point. Oral anticoagulants were prescribed for 2,082 (58.1%) patients (warfarin, 1,214; direct oral anticoagulants [DOACs], 868). Incidence and observation period (maximum 3 years) of IS, extracranial hemorrhage (ECH), and intracranial hemorrhage (ICH) were counted separately for the northern hemisphere seasons. During the mean follow-up period of 2.4 years, there were totals of 90 IS, 73 ECH, and 33 ICH cases. The respective incidence rates per 1,000 patient-years in spring, summer, autumn, and winter were 8.5, 8.8, 7.5, and 16.8 for IS, 7.2, 9.7, 3.8, and 13.1 for ECH, and 2.7, 1.9, 3.8, and 7.0 for ICH. The number of patients with DOACs relatively increased among those with ECH in summer., Conclusions: Significant seasonal variations were observed for IS, ECH, and ICH events in AF patients, and were consistently the highest in winter. A small peak of ECH was observed in summer, which seemed, in part, to be related to increased DOAC use.

Wolbachia are ubiquitous bacterial endosymbionts of arthropods and affect host gene expression. Although Wolbachia infections were suggested to modulate sleep in flies, their influence on the circadian clock remained obscure. Here, we screened bacterial symbionts in a laboratory Drosophila melanogaster colony, and observed widespread infections of wMel strain Wolbachia. We established a Wolbachia-free strain from a clock gene reporter strain, period-luciferase (per-luc). Temperature (19-29 °C)-compensated free-running periods were detected regardless of infections which may reflect the lack of wMel infections in central circadian pacemaker neurons. However, locomotor activity levels during the night or subjective night were significantly amplified in uninfected flies. Moreover, the behavioral phenotype of F1 offspring of an uninfected female and infected male resembled that of uninfected flies. This trait is consistent with maternal transmission of Wolbachia infection. Interestingly, per-luc activities in headless bodies, as an index of peripheral circadian oscillators, were severely damped in uninfected flies. Additionally, circadian amplitudes of PER immunoreactivities in Malpighian tubules were reduced in uninfected flies. These results demonstrate that Wolbachia boost fly peripheral clock oscillations and diurnal behavioral patterns. Genetic mechanisms underlying behavioral rhythms have been widely analyzed using mutant flies whereas screening of Wolbachia will be necessary for future studies.

The preventive effect of estrogen on Alzheimer's disease (AD) has become clearer with many epidemiological reports. However, the therapeutic effects of estrogen have been controversial until now. In our trials, estrogen treatment showed a beneficial therapeutic effect for women with mild to moderate AD. Improvement of cognitive function was recognized during the third week from the beginning of administration and maintained as long as estrogen treatment continued. The longer the duration of HRT, the more HRT is useful for the prevention and therapy of AD. However, in most cases, administration of estrogen is discontinued because of the adverse effects on the uterus and breast. J 861 is a derivative of estradiol-17alpha, which has little effect on the sexual organs. The effects of estradiol-17beta (E2) and J 861 on neuronal function and vascular factors were investigated. J 861 was suggested to prevent both the intracellular calcium increase and peroxidation induced by amyloid beta (Abeta), more effectively than E2. The effect of J 861 may be related with both the direct non-genomic and the ER-mediated systems. J 861 showed neurotrophic effects like E2. J 861 inhibited the adhesion of monocytes to vascular endothelium, more effectively than E2. Also, J 861 suppressed the expression of adhesive factors, such as E-selectin and intercellular cell adhesion molecule-1 (ICAM-1), more effectively than E2.

Although recent studies have shown that radiation can induce metallothionein (MT) synthesis in normal tissues, the induction of tumor MT synthesis by irradiation has not been reported. We examined the accumulation of MT in the Meth-A tumor (mouse fibrosarcoma cells) transplanted into mice exposed to whole-body X irradiation. In the present study, the MT content in the tumor cells was increased by X irradiation in a dose-dependent manner. The MT level induced in the tumor cells by X irradiation was elevated not only after a single exposure but also after repeated exposures. Several studies have shown that MT is one of the important cellular factors in resistance to various anticancer drugs and ionizing radiation. Thus our results suggest that the radiation-induced MT in the tumor cells may have to be taken into consideration when designing protocols for radio- and chemotherapy.

In our clinic, we encountered 8 patients with pseudocyst of the auricle during a 6-year period from 1987 to 1992 and injected steroid solution locally into the pseudocysts. Three of these patients had no recurrences and 4 were treated successfully after 1-3 recurrences. In only one case was this therapy ineffective. After 11 injections, which resulted in permanent deformity of the auricle, the patient underwent surgery. We believe that local steroid injection therapy should be the first choice method for treating auricular pseudocysts. However, frequent injections can cause auricular deformity and if there are more than 3 recurrences, the pseudocyst should be managed surgically. The lactate dehydrogenase levels of the cystic fluid were determined in 3 of the 8 patients and proved high; in only one patient was the etiology of the pseudocyst thought to be associated with minor trauma.