Visualization of Charge Migration in Conductive Polymers via Time-Resolved Electrostatic Force Microscopy

Charge dynamics play an important role in numerous natural phenomena and artificial devices, and tracking charge migration and recombination is crucial for understanding the mechanism and function of systems involving charge transfer. Tip-synchronized pump–probe electrostatic force microscopy simultaneously permits highly sensitive detection, microsecond time resolution, and nanoscale spatial resolution, where the spatial distribution in static measurement (usual EFM) reflects differences in the carrier density and the time evolution reveals the surface carrier mobility. By using this method, carrier injection and ejection in sulfonated polyaniline (SPAN) thin films were visualized. Comparison of tr-EFM results of SPAN thin films with different doping levels revealed the individual differences in carrier density and mobility

Local-field-induced current noise in shape-limited self-doped polyaniline

Electronic noise generators are an essential component of molecular neuromorphic devices. To realize molecular noise generators with a high degree of freedom for design and integration into molecular devices, the utilization of the local electric field for the modulation of electrical conduction via a shape-limited conductive polymer is one promising strategy. Herein, a molecular noise generator composed of thin self-doped polyaniline (SPAN) lines is reported. SPAN lines fabricated via fountain pen lithography on SiO2/Si substrates were found to generate current noise upon laser irradiation. This current noise exhibited white-noise-like power spectral density in the frequency range of 1–25 Hz and was independent of temperature. Multiple independent noise generation on the same substrate was also successfully demonstrated. The present results indicate that the noise generation mechanism involves the local modulation of hopping conduction via SPAN lines owing to the spatial proximity of the conduction path in the SPAN line to the surface photovoltage region of the SiO2/Si interface. This on-site random noise generation in shape-limited conductive polymers is expected to be beneficial for the realization of molecular neuromorphic devices

Active Hippocampal Networks Undergo Spontaneous Synaptic Modification

The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic connectivity without any external (or artificial) stimuli. Under physiologically relevant ionic conditions, CA3 pyramidal cells in hippocampal slices displayed spontaneous spikes with bistable slow oscillations of membrane potential, alternating between the so-called UP and DOWN states. The generation of slow oscillations did not require fast synaptic transmission, but their patterns were coordinated by local circuit activity. In the course of generating spontaneous activity, individual neurons acquired bidirectional long-lasting synaptic modification. The spontaneous synaptic plasticity depended on a rise in intracellular calcium concentrations of postsynaptic cells, but not on NMDA receptor activity. The direction and amount of the plasticity varied depending on slow oscillation patterns and synapse locations, and thus, they were diverse in a network. Once this global synaptic refinement occurred, the same neurons now displayed different patterns of spontaneous activity, which in turn exhibited different levels of synaptic plasticity. Thus, active networks continuously update their internal states through ongoing synaptic plasticity. With computational simulations, we suggest that with this slow oscillation-induced plasticity, a recurrent network converges on a more specific state, compared to that with spike timing-dependent plasticity alone

Protocol for a randomized study of the efficacy of ibandronic acid plus eldecalcitol in patients with gastric cancer after gastrectomy: A comparative study of different routes of administration of ibandronic acid [version 2; peer review: 2 approved]

Background: Patients who undergo gastrectomy for gastric cancer are susceptible to osteoporosis. To prevent a decrease in bone mineral density, an appropriate prophylaxis is considered important to adjust the post-gastrectomy condition. In this study, we will compare two different routes of administration of ibandronic acid (oral or intravenous) plus eldecalcitol as a potentially more suitable treatment for patients at a high risk of fragile fracture. Protocol: This study protocol describes a randomized, active-controlled, non-blind, single-center, phase II trial. For patients in the investigational arm (Group A), sodium ibandronate hydrate will be administered intravenously once a month with daily oral intake of eldecalcitol; for those in the control arm (Group B), sodium ibandronate hydrate will be administered orally once a month with daily oral intake of eldecalcitol. We will recruit patients aged 45–85 years who have undergone gastrectomy for gastric cancer and are at a risk of fragility fractures. The study will include patients with existing vertebral fractures and/or femoral proximal fractures, or with lumbar and/or proximal femur bone mineral density of less than 80% of the young adult mean. The primary outcome of this study will be the change in lumbar bone mineral density. We will also evaluate the changes in femur bone mineral density, bone metabolism markers, health-related quality of life as evaluated using the EuroQol 5 Dimension (EQ-5D), and digestive symptoms as evaluated using the Gastrointestinal Symptom Rating Scale after 52 weeks of treatment. Conclusions: We believe that appropriate treatments that are adjusted to the condition of patients after gastrectomy are important for the prevention of bone mineral loss. Registration: This study was accepted by the Japan Registry of Clinical Trials (jRCT1041200059, November 6, 2021)

Evaluation of lower extremity gait analysis using Kinect V2(R) tracking system

名古屋市立大学博士 (医学)doctoral thesi

Pathological Evaluation of Sentinel Lymph Nodes for Breast Cancer

Recently, sentinel lymph node (SLN) biopsy has been employed to avoid unnecessary lymph node dissection, because SLN negativity for carcinoma metastases may imply an extremely low possibility of non-SLN involvement. Pathological evaluation is essential, but standardized procedures have not yet been determined. Intraoperative consultation, either by frozen section (multiple slices are desirable) or touch imprint cytology, are usually very useful. Their accuracy, however, is variable and depends on the procedures used, but specificity is characteristically 100%, and the missed metastatic focus is always quite minute. After fixation, multiple sections, immuno-histochemistry, and their combination will be able to detect small metastatic foci more frequently. The clinical significance of small or submicro- or occult metastases have not yet been clarified, and further investigations are needed. If the SLN is positive for carcinoma metastases, both the procedure for detection and the size of the metastatic focus should be clarified on the pathological reports

Prognostic value of myocardial perfusion SPECT images in combination with the maximal heart rate at exercise testing in Japanese patients with suspected ischemic heart disease: A sub-analysis of J-ACCESS

Objectives We assessed whether a combination of summed stress scores (SSS) using exercise myocardial perfusion SPECT (Ex-SPECT) and maximal heart rate accurately predicts cardiac events through a sub-analysis of J-ACCESS (Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT) which was conducted to evaluate the prognosis of Japanese patients with suspected ischemic heart disease. Methods In J-ACCESS, 2, 373 patients with suspected coronary artery disease not receiving beta-blocker treatment underwent Ex-SPECT. These patients were categorized into the following four groups: Group A [achieved target heart rate (THR) and SSS < 4: n = 631], B (did not achieve THR and SSS < 4: n = 612), C (achieved THR and SSS ≥ 4: n = 570), and D (did not achieve THR and SSS ≥ 4: n = 560). We evaluated the incidence rate of cardiac events including cardiac death, myocardial infarction, and heart failure requiring hospital admission during a 3-year period. Results In Group A, B, C, and D, 9 of 631 (1.4%), 15 of 612 (2.4%), 23 of 570 (4.0%) and 30 of 560 (5.4%) patients experienced cardiac events, respectively. Although the hazard ratio of the SSS ≥ 4 was 2.45 (p < 0.001) and that of the attained THR was 0.69 (p = 0.10) in the multiple Cox regression analysis, Kaplan–Meier curves showed that the cardiac events rate was lower in the order of A, B, C, and D (p < 0.001). Conclusion The combination of SSS using Ex-SPECT and the maximal heart rate is a useful predictor of cardiac events in patients with suspected coronary artery disease