Cd-content and temperature dependences of hyperfine fields in CdxFe3-xO4 (0 ≤ x ≤ 0.5) were investigated by means of time-differential perturbed angular correlation spectroscopy with the 111Cd(←111In) probe. It was found that Cd2+ ions selectively occupy the tetrahedral A site in the spinel structure in all the range of the present Cd content x. The magnetic transition temperature TC becomes lower with increasing x due to the interference of the long-range ordering of Fe spins as a result of expansion of the lattice constants by Cd doping. The measurement of room-temperature hyperfine fields at different x shows that the supertransferred magnetic hyperfine field (SMHF) at the probe decreases as x increases in the range of 0 ≤ x ≤ 0.5. Isothermal measurements at 15 K revealed a contrastive phenomenon for the Cd contents up to x = 0.4: the SMHF becomes great with increasing x; however, this increasing trend of the SMHF turns to reduction at x = 0.46. These observations can be explained based on the effect of Cd doping on the antiferromagnetic coupling between Fe ions in the A and B sites.

The muon spin rotation/relaxation/resonance ( μ SR) spectroscopy is widely used as a unique tool for probing magnetic properties in materials. We aim to enhance this method by incorporating imaging functionality. In this study, we conducted an experiment using a new imaging device that utilizes positron tracking from muon decays to assess the reliability of positron tracking and its positional resolution. As a result, we have demonstrated that an image depicting a hole with a diameter of 5 mm could be reconstructed.

Muon spin relaxation/rotation/resonance ( μSR ) method is one of the most effective experimental methods and has been used in many fields such as material science, chemical, and bioscience since the 1970s. For the next elevation of μSR , we developed positron detectors that have a spatial resolution and used them as positron trackers so that we could construct an image of a sample. Demonstrative experiments of trackers were performed at TRIUMF and an image of a sample was successfully reconstructed.

Cd-content and temperature dependences of hyperfine fields in CdxFe3-xO4 (0 ≤ x ≤ 0.5) were investigated by means of time-differential perturbed angular correlation spectroscopy with the 111Cd(←111In) probe. It was found that Cd2+ ions selectively occupy the tetrahedral A site in the spinel structure in all the range of the present Cd content x. The magnetic transition temperature TC becomes lower with increasing x due to the interference of the long-range ordering of Fe spins as a result of expansion of the lattice constants by Cd doping. The measurement of room-temperature hyperfine fields at different x shows that the supertransferred magnetic hyperfine field (SMHF) at the probe decreases as x increases in the range of 0 ≤ x ≤ 0.5. Isothermal measurements at 15 K revealed a contrastive phenomenon for the Cd contents up to x = 0.4: the SMHF becomes great with increasing x; however, this increasing trend of the SMHF turns to reduction at x = 0.5. These observations can be explained based on the effect of Cd doping on the antiferromagnetic coupling between Fe ions in the A and B sites.

The effects of hydrogen absorption on the local lattice structure in palladium (Pd) were investigated by means of positron annihilation lifetime spectroscopy (PALS) and time-differential perturbed angular correlation (TDPAC) spectroscopy. The PALS measurements demonstrated that dislocations and vacancies formed in the preparation process of a pristine Pd plate can be clearly removed by vacuum annealing at 1073 K and the subsequent absorption of a large quantity of hydrogen, resulting in the production of the β-phase hydride PdH0.62, induces the formation of the open-volume defects again. It was also found that the absorbed hydrogen atoms remain in the Pd sample at 323 K but they are completely evacuated during 5 h heating at 383 K. In addition to the overall thermal behavior, an atomic scale observation of the hydrogen dynamics was carried out by means of TDPAC spectroscopy, indicating the nuclear quadrupole relaxation of the present (111m,111Pd → 111Ag→)111Cd probe, which evidently suggests that the hydrogen atoms show fast dynamic motion around the probe. From the temperature-dependent nuclear quadrupole relaxation rate, we obtained an activation energy of 41(4) meV for the motion.

In the present study, we investigated the relation between photocatalytic properties and local structures of SrTiO 3 perovskite oxides doped with 0.1–10 at.% indium. From the measurement of photocatalytic degradation of methylene blue (MB), it was found that the In 3+ doping improved the photocatalytic activity of SrTiO 3 . To understand the defect structure arising from In doping, local structures in SrTiO 3 were investigated by the time-differential perturbed angular correlation (TDPAC) method with the 111 Cd(← 111 In) probe. Part of the thermally diffused In ions occupy defect-free substitutional Ti sites in cubic SrTiO 3 structure; however, most of the doped In ions occupy the substitutional Ti 4+ sites where oxygen vacancy exists in the vicinity of the probes. It was also suggested that the concentration of In 3+ reached the solubility limit in SrTiO 3 and formed a secondary phase at 1 at.% In doping, resulting in the suppression of photocatalytic activity of SrTiO 3 . For the photocatalysis of In-doped SrTiO 3 synthesized by the conventional solid-state reaction, we found that optimal indium doping is in the concentration range of 0.1–1 at.%.

Fe doping effect on the local magnetic property of La 0.7 Ca 0.3 Mn 1− x Fe x O 3 (0.4 ≤ x ≤ 0.55) was investigated by means of 57 Fe Mössbauer spectroscopy. The X-ray diffraction patterns and the isomer shifts of the 57 Fe Mössbauer spectra demonstrate that all the Fe ions are high-spin trivalent and share the B site lattice positions with Mn ions. The sample of La 0.7 Ca 0.3 Mn 0.6 Fe 0.4 O 3 ( x = 0.4) was found to be in the paramagnetic state even at 8 K. For the samples with high Fe contents, however, magnetic sextet(s) arising from local magnetic ordering were observed in the low-temperature spectrum of La 0.7 Ca 0.3 Mn 0.5 Fe 0.5 O 3 ( x = 0.5), and also in all the spectra of La 0.7 Ca 0.3 Mn 0.45 Fe 0.55 O 3 ( x = 0.55) measured in the range of 8 K—room temperature. These observations suggest that randomly distributed Fe 3+ ions interfere with the double exchange interaction in Mn 3+ –O–Mn 4+ , and antiferromagnetic ordering arises from superexchange interaction in Fe 3+ –O–Fe 3+ at high Fe content.

In the present work, we have succeeded in controlling association-dissociation process of thermally activated In impurities introduced in polycrystalline ZnO by a multistep doping method. The thermal behavior and eventual residential sites of In ions were monitored on an atomic scale by means of time-differential perturbed angular correlation spectroscopy with the In-111(-> Cd-111) probe. The present doping method of combined heat treatments in air and in vacuum enabled the introduction of a great fraction of 0.5 at.% In donors into defect-free substitutional Zn sites. It was demonstrated that the In-containing ZnO samples show a clear positive correlation between the electrical conductivity and the concentration of In donors at substitutional Zn sites, achieving a conductivity as high as five orders of magnitude compared with undoped ZnO.

STUDY QUESTION: Is there a relation between specific Na+/K+ ATPase isoform expression and localization in human blastocysts and the developmental behavior of the embryo? SUMMARY ANSWER: Na+/K+ ATPase alpha 1, beta 1 and fn are the main isoforms expressed in human blastocysts and no association was found between the expression level of their respective mRNAs and the rate of blastocyst expansion. WHAT IS KNOWN ALREADY: In mouse embryos, Na+/K+ ATPase aI and ill are expressed in the basolateral membrane of trophectoderm (TE) cells and are believed to be involved in blastocoel formation (cavitation). STUDY DESIGN, SIZE, DURATION: A total of 20 surplus embryos from I I patients who underwent IVF and embryo transfer at a university hospital between 2009 and 2018 were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS: After freezing and thawing Day 5 human blastocysts, their developmental behavior was observed for 24 h using time-lapse imaging, and the expression of Na+/K+ ATPase isoforms was examined using quantitative RT-PCR (RT-qPCR). The expressed isoforms were then localized in blastocysts using fluorescent immunostaining. MAIN RESULTS AND THE ROLE OF CHANCE: RT-qPCR results demonstrated the expression of Na+/K+ ATPase alpha 1, beta 1 and beta 3 isoforms in human blastocysts. lsoforms alpha 1 and beta 3 were localized to the basolateral membrane of TE cells, and PI was localized between TE cells. A high level of ID mRNA expression correlated with easier hatching (P = 0.0261). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The expression of mRNA and the localization of proteins of interest were verified, but we have not been able to perform functional analysis. WIDER IMPLICATIONS OF THE FINDINGS: Of the various Na+/K+ ATPase isoforms, expression levels of the alpha 1, beta 3 and beta 3 mRNAs were clearly higher than other isoforms in human blastocysts. Since alpha 1 and were localized to the basolateral membrane via fluorescent immunostaining, we believe that these subunits contribute to the dilation of the blastocoel. The beta 3 isoform is localized between TE cells and may be involved in tight junction formation, as previously reported in mouse embryos.

Abstract Study question In Japan, how much of freezing cost and the yearly storage cost of medical and social egg freezing for fertility preservation is clearly disclosed on the institution's website? Summary answer Of the 621 infertility treatment institutions, 146 listed egg freezing on their websites, 46 specified the freezing cost, and 71 specified the yearly storage cost. What is known already In Japan, from April 2022, standard assisted reproductive technology will be covered by insurance, but medical and social egg freezing will continue to be privately funded. Therefore, it is unclear how many facilities in Japan perform egg freezing. Furthermore, while the cost of freezing and yearly storage varies significantly from facility to facility, there has been no data comparing egg freezing among facilities in Japan or other countries. Therefore, we extracted data about freezing and storage cost from each institution's website and compared them for the first time. Study design, size, duration This study is a web-based survey in which a single board-certified specialist by Japan Society for Reproductive Medicine exhaustively browsed the websites of all 621 fertility treatment institutions in Japan in October 2021 and analyzed the implementation of egg freezing, freezing costs, and yearly storage costs of egg are clearly stated on the websites. The costs of drugs used for egg retrieval and ovarian stimulation were excluded. Participants/materials, setting, methods Of the 621 institutions, 88 institutions that clearly stated on their websites that they offer egg freezing for medical reasons were divided into a medical group, and 58 institutions that clearly stated that they offer egg freezing for only social reasons were divided into social group for statistical analysis. We compared the freezing and the yearly storage cost, respectively, whether it varies depending on the number of eggs or whether it is a fixed cost. Main results and the role of chance Of the 621 institutions, 146 (23.5%), 88 in the medical group and 58 in the social group, specified that they offer egg freezing. The percentages of clarification for freezing cost and yearly storage cost on the website were 27.3% and 30.7% in the medical group, 72.4%, and 75.9% in the social group, so the social group was higher in both cases (p < 0.01). The percentage of fixed costs for egg freezing was significantly lower in the social group (6/42, 14.3%) than in the medical group (9/24, 37.5%) (p < 0.05). The percentage of fixed costs for yearly storage cost was samely significantly lower in the social group (30/44, 68.2%) than in the medical group (25/27, 92.6%) (p < 0.05). The mean freezing cost/yearly storage cost was as follows for 1, 5, and 10 eggs. The medical group was (JPY45,527/JPY22,327, JPY65,179/JPY22,530, JPY90,311/JPY22,770), and the social group was (JPY56,822/JPY40,178, JPY88,429/JPY56,502, JPY136,550/JPY79,090), so the social group had the significantly highest amount of costs in each case. Note that JPY 10,000 is about EUR77.7. The most expensive clinic to store ten eggs was JPY500,000 (EUR3,883) per year, and the least university hospital was JPY 4,600 (EUR35.7) per year. Limitations, reasons for caution This survey was conducted by carefully browsing the facility's website, but since we did not confirm the information through questionnaires or e-mail, there is the possibility that the information may have been updated. Another limitation is that less than half of the medical groups list cost details on their websites. Wider implications of the findings This is the first report to analyze the cost of egg freezing in Japan using the institution's website. The rate of cost disclosure on the website is still low. Moreover, the costs of social freezing are significantly higher than medical reasons, but this may change with the insurance of ART. Trial registration number not applicable

The 57Fe Mössbauer spectrum obtained after 57Mn (T1/2 = 1.45 min) implantation of solid hydrogen was measured at 7 K. The spectrum was analyzed as three components, and the chemical species of each component was assigned from the obtained Mössbauer parameters and the results of density functional theory (DFT) calculations. The formation process of chemical species and the oxidation states of Fe atoms produced by β– decay of 57Mn are discussed considering the charge transfer process, in relation to previous emission Mössbauer spectroscopy experiments with 57Co implantation of solid hydrogen at low temperature.

Minute examination of local lattice structures in matter affected by impurity doping is of special importance for the development of functional materials. In order to obtain microscopic information on spinel ferrites, in the present work, we introduced nonmagnetic In3+ ions in Fe3O4 and probed their site selectivity and the doping effect on the local lattice structures and bulk magnetism by means of 57Fe Mössbauer spectroscopy and positron annihilation spectroscopies. The Mössbauer parameters of the area intensity and isomer shift (IS) show that In3+ ions predominantly reside in the tetrahedral A site, especially at low doping level. With increasing concentration of In ions, however, they gradually occupy the octahedral B site replacing Fe3+ ions. Along with the site information, the IS values confirmed that the introduced In ions squeeze the B-site Fe ions at their nearest neighbors. Supporting results were obtained from positron annihilation lifetime spectroscopy; positron lifetimes become shorter with increasing In concentration, signifying that the oxygen ions are pressed by the introduced In ions resulting in lowering the volume of the adjacent lattice vacancies. The results of Doppler broadening spectroscopy also support the squeezing effect; the positrons in the vacancies adjacent to In ions are more likely to annihilate with the inner shell electrons of the surrounding oxygen ions as a result of a reduction in the vacancy volume.

In-beam Mössbauer spectra of 57Mn implanted into LiAlH4 were measured at different temperatures between 17 and 300 K. The Mössbauer spectrum measured at 17 K showed two sets of doublets, which were assigned to 57Fe atoms at substitutional sites at Al3+ and Li+ sites. The Debye temperatures θM for the 57Fe atoms at Al3+-substituted and Li+-substituted sites were estimated to be 194 K and 117 K, respectively. The assignments were confirmed by density functional theory calculations.

Co content (x) dependences of cationic distribution and local fields at the tetrahedral A-site and octahedral B-site nuclei in Co ferrites, CoxFe3−xO4 (x = 0–1.0), were investigated by means of hyperfine interaction techniques. A combined investigation by 57Fe transmission and 57Co emission Mössbauer spectroscopies revealed that about 6% of Co2+ ions occupy the A sites for the sample with Co contents of x = 0 and 1.0. This observation evidently suggests that the site selectivity of Co2+ ions is independent of x for samples prepared on the same heat treatment condition. For hyperfine interaction parameters, obvious x dependence was observed for the B-site Fe nuclei, reflecting variation of the atomic ratio of Fe3+/Fe2+ changing with x, whereas for the A-site Fe nuclei, the parameters hardly change along with x. Contrary to the x-independence for the A-site Fe nuclei, however, it was demonstrated by perturbed angular correlation spectroscopy with the nonmagnetic probe 111Cd(←111In) that the hyperfine field at the A site significantly changes along with x. These contradictory results on the A-site fields verify that the nonmagnetic probe can distinguish a subtle change in the local fields with higher sensitivity.

Abstract Background Vascular inflammation plays a fundamental role in most vascular diseases including atherosclerosis and vasculitis syndrome, in which arterial wall vascularization (AWV) frequently develops. Visualization of AWV is informative in detecting the vascular inflammation but is challenging. A new ultrasound technique (superb micro-vascular imaging [SMI]) allows the detection of extremely low-velocity flows. We examined an availability of SMI for assessment of the instability of atherosclerotic plaques and the activity of Takayasu arteritis (TA). Methods and results The study consists of two independent and consecutive parts A and B, examined in carotid stenosis (A) and TA (B), respectively. In part A, 12 patients with symptomatic severe carotid stenosis (CS group) scheduled for carotid endarterectomy were enrolled. In six of 12 patients, preoperative ultrasonography with SMI showed intraplaque neovascularization at the plaque shoulder. Postoperatively, histopathology confirmed the neovessels at the corresponding sites of visualized AWV. SMI had a sensitivity of 67%, specificity of 90% for detection of AWV in CS group. In SMI analysis, false positive findings were caused by motion artifact and arterial wall calcification, and a false negative finding is attributed by intraplaque hemorrhage. In part B, 10 patients with TA were enrolled. All patients underwent 18F-FDG-PET/CT, and its vascular uptake were compared with AWV detected by SMI. Bilateral common carotid arteries (CCA), internal carotid arteries and common iliac arteries were examined by SMI. Active vascular 18F-FDG uptake (max SUV >2.1) were found at five sites in three patients, which were not significantly correlated with the prevalence of macaroni sign, increase in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Of note, SMI revealed AWV at five sites corresponding to uptake of 18F-FDG, with a sensitivity/specificity of 100% and 98%, positive predictive value 71%, and a negative predictive value 100%. Conclusion SMI enables visualization of AWV at vulnerable plaque in CS patients and at 18F-FDG positive sites in TA patients. SMI has potential as a modality to detect the vascular inflammation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research, Japan

The concentration of hydrogen impurities (H) incorporated in hydrothermally grown ZnO single crystals and their thermal behaviors were investigated by means of H-1(N-15,alpha gamma)C-12 nuclear reaction analysis (NRA) and positron annihilation lifetime spectroscopy (PALS). The H concentration measurements with NRA suggest that H exist in three different bound states in as-grown ZnO: two types of loosely bound H (LBH) and a strongly bound H (SBH). The LBH are removed out of the reaction site by heat treatment up to 773 K but SBH remain even at 1373 K. The PALS measurements demonstrate the presence of (zinc vacancy)-H complexes (V-Zn + H) which also remain at 1373 K. Comparison with earlier theoretical calculations suggests that the SBH exist as V-Zn + H at a concentration of 0.10(4) at.%.

To investigate the interactions of 57Fe atoms with sulfur hexafluoride SF6 molecules, in-beam Mössbauer spectra were measured for 57Mn implanted SF6 at 9 K and 65 K. Isolated 57Fe atoms or ions produced by β-decay were not trapped within the SF6 matrix. At 9 K, monomeric FeF2 and FeF3 molecules were produced by reaction of 57Fe with F atoms released by decomposition of the SF6 molecules. When the temperature of the SF6 solid was increased to 65 K, FeF4 was formed in addition to FeF2 and FeF3. Density functional calculations were performed to confirm the assignments of the candidate species identified in the Mössbauer spectra.

The formation process of lattice defects in single crystals of ZnO and their contribution to electric conduction were investigated by means of electric conductivity measurements and positron annihilation lifetime spectroscopy (PALS). For the ZnO samples once heated at high temperatures between 1073 K and 1273 K, we observed defect-induced n-type conductivity by sample warming or light irradiation to the sample, suggesting that interstitial zinc atoms (Zn-i) and oxygen vacancies (V-O) as shallow and deep donors, respectively, were formed by the high-temperature heating. After heat treatment at 1373 K, however, the conductivity arises only from thermal excitation by sample warming, demonstrating that only Zn-i contributes to the conductivity but V-O does not. Based on the above observation and the results of PALS measurements for the samples heated at high temperature, we propose a mechanism of the n-type conduction in ZnO that carrier electrons are provided by interstitial zinc atoms as a result of electron-hole cancellation through interaction between zinc vacancies (V-Zn) and V-O.

The magnetic hyperfine field and electric field gradients at a radioactive impurity probe of Cd-111(<- Cd-111m) occupying the La/Ca A site in a perovskite manganaite La0.7Ca0.3MnO3 (T-C similar to 250 K) were measured by means of time-differential perturbed angular correlation (TDPAC) spectroscopy. In the paramagnetic-insulator phase at room temperature, the Cd-111(<- Cd-111m) probes are distributed in two different environments: distorted and less distorted sites; whereas in the ferromagnetic-metal phase below T-C, the oscillatory structure of the distorted component vanishes from the TDPAC function. The vanishing of the oscillation is ascribable to dynamic motion of polarons dragged by conduction electrons induced by the double exchange interaction. In liquid helium, the dynamic motion freezes, leaving averaged local distortion. The dynamic motion and freezing of local structures associated with the colossal-magnetoresistance phase transition to the ferromagnetic phase is discussed on the basis of temperature-dependent electromagnetic fields at the probe nuclei of the A site ions.