Enhancement by streptozotocin of O−2 radical generation by the xanthine oxidase system of pancreatic β-cells

AbstractSpin-trapping techniques and electron spin resonance (ESR) spectroscopy were used to study the relationship between the effect of streptozotocin (STZ) on pancreatic β-cells and free radical formation by these cells. Results showed that STZ enhanced generation of the DMPO-OH radical adduct, which is a degradation product of the superoxide anion (O−2) in the presence of cellular components, in a hypoxanthine-xanthine oxidase (XOD) system with a homogenate of β-cells. This enhancing effect was also observed in a system without cellular components; STZ increased the signal height due to the O−2 radical in a concentration-dependent manner and caused a maximum of 150% enhancement at a concentration of 1.5 mM. Thus, STZ seemed to enhance the generation of the O−2 radical in the XOD system, probably by some mechanism of its interaction with XOD. Pancreatic β-cells exhibited a high XOD activity and a very low superoxide dismutase activity. Therefore, the present result supports the possibility that the cytotoxic effect of STZ is closely related to free radical generation in pancreatic β-cells

Dynamical invariants for quantum control of four-level systems

We present a Lie-algebraic classification and detailed construction of the dynamical invariants, also known as Lewis-Riesenfeld invariants, of the four-level systems including two-qubit systems which are most relevant and sufficiently general for quantum control and computation. These invariants not only solve the time-dependent Schr\"odinger equation of four-level systems exactly but also enable the control, and hence quantum computation based on which, of four-level systems fast and beyond adiabatic regimes.Comment: 11 pages, 5 table

Particle therapy for prostate cancer: The past, present and future

Although prostate cancer control using radiotherapy is dose‐dependent, dose–volume effects on late toxicities in organs at risk, such as the rectum and bladder, have been observed. Both protons and carbon ions offer advantageous physical properties for radiotherapy, and create favorable dose distributions using fewer portals compared with photon‐based radiotherapy. Thus, particle beam therapy using protons and carbon ions theoretically seems suitable for dose escalation and reduced risk of toxicity. However, it is difficult to evaluate the superiority of particle beam radiotherapy over photon beam radiotherapy for prostate cancer, as no clinical trials have directly compared the outcomes between the two types of therapy due to the limited number of facilities using particle beam therapy. The Japanese Society for Radiation Oncology organized a joint effort among research groups to establish standardized treatment policies and indications for particle beam therapy according to disease, and multicenter prospective studies have been planned for several common cancers. Clinical trials of proton beam therapy for intermediate‐risk prostate cancer and carbon‐ion therapy for high‐risk prostate cancer have already begun. As particle beam therapy for prostate cancer is covered by the Japanese national health insurance system as of April 2018, and the number of facilities practicing particle beam therapy has increased recently, the number of prostate cancer patients treated with particle beam therapy in Japan is expected to increase drastically. Here, we review the results from studies of particle beam therapy for prostate cancer and discuss future developments in this field

Random regression for modeling soybean plant response to irrigation changes using time-series multispectral data

Plant response to drought is an important yield-related trait under abiotic stress, but the method for measuring and modeling plant responses in a time series has not been fully established. The objective of this study was to develop a method to measure and model plant response to irrigation changes using time-series multispectral (MS) data. We evaluated 178 soybean (Glycine max (L.) Merr.) accessions under three irrigation treatments at the Arid Land Research Center, Tottori University, Japan in 2019, 2020 and 2021. The irrigation treatments included W5: watering for 5 d followed by no watering 5 d, W10: watering for 10 d followed by no watering 10 d, D10: no watering for 10 d followed by watering 10 d, and D: no watering. To capture the plant responses to irrigation changes, time-series MS data were collected by unmanned aerial vehicle during the irrigation/non-irrigation switch of each irrigation treatment. We built a random regression model (RRM) for each of combination of treatment by year using the time-series MS data. To test the accuracy of the information captured by RRM, we evaluated the coefficient of variation (CV) of fresh shoot weight of all accessions under a total of nine different drought conditions as an indicator of plant’s stability under drought stresses. We built a genomic prediction model (MTRRM model) using the genetic random regression coefficients of RRM as secondary traits and evaluated the accuracy of each model for predicting CV. In 2020 and 2021,the mean prediction accuracies of MTRRM models built in the changing irrigation treatments (r = 0.44 and 0.49, respectively) were higher than that in the continuous drought treatment (r = 0.34 and 0.44, respectively) in the same year. When the CV was predicted using the MTRRM model across 2020 and 2021 in the changing irrigation treatment, the mean prediction accuracy (r = 0.46) was 42% higher than that of the simple genomic prediction model (r =0.32). The results suggest that this RRM method using the time-series MS data can effectively capture the genetic variation of plant response to drought

Identification of novel biomarker candidates by proteomic analysis of cerebrospinal fluid from patients with moyamoya disease using SELDI-TOF-MS

<p>Abstract</p> <p>Background</p> <p>Moyamoya disease (MMD) is an uncommon cerebrovascular condition with unknown etiology characterized by slowly progressive stenosis or occlusion of the bilateral internal carotid arteries associated with an abnormal vascular network. MMD is a major cause of stroke, specifically in the younger population. Diagnosis is based on only radiological features as no other clinical data are available. The purpose of this study was to identify novel biomarker candidate proteins differentially expressed in the cerebrospinal fluid (CSF) of patients with MMD using proteomic analysis.</p> <p>Methods</p> <p>For detection of biomarkers, CSF samples were obtained from 20 patients with MMD and 12 control patients. Mass spectral data were generated by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) with an anion exchange chip in three different buffer conditions. After expression difference mapping was undertaken using the obtained protein profiles, a comparative analysis was performed.</p> <p>Results</p> <p>A statistically significant number of proteins (34) were recognized as single biomarker candidate proteins which were differentially detected in the CSF of patients with MMD, compared to the control patients (p < 0.05). All peak intensity profiles of the biomarker candidates underwent classification and regression tree (CART) analysis to produce prediction models. Two important biomarkers could successfully classify the patients with MMD and control patients.</p> <p>Conclusions</p> <p>In this study, several novel biomarker candidate proteins differentially expressed in the CSF of patients with MMD were identified by a recently developed proteomic approach. This is a pilot study of CSF proteomics for MMD using SELDI technology. These biomarker candidates have the potential to shed light on the underlying pathogenesis of MMD.</p

Towards a Search for the Muon Electric Dipole Moment using the Frozen-spin Technique

The search for a permanent electric dipole moment (EDM) of the muon is a unique probe to explore additional charge-parity (CP) violation sources beyond the CP violating phase of the Cabibbo–Kobayashi–Maskawa matrix in the Standard Model (SM) of particle physics. Any detection of a non-zero EDM at the current experimental sensitivity would be a strong signal of new CP violation sources that can be modelled in many theories Beyond the Standard Model (BSM) physics. Particularly, BSM models that allow for a large muon EDM without a tight constraint from an electron EDM are often intrinsically linked to the reported 4.2σ deviation from the SM prediction in the anomalous magnetic dipole moment of a muon. The observed tensions between measurements and SM predictions in B-decays also support similar models. This makes the muon EDM search pivotal to further push EDM searches beyond the first generation of fundamental particles with the potential of disentangling a possible violation of the lepton flavour universality. At the Paul Scherrer Institute (PSI), the first dedicated muon EDM search employing the frozen-spin technique is on its way. The muon EDM experiment aims for a sensitivity of better than 6 × 10⁻²³ e·cm, more than three orders of magnitude improvement over the current best upper limit placed by the E821 experiment at Brookhaven National Laboratory. In preparation for a dedicated high precision muon EDM measurement, this thesis covers three main areas. Firstly, the definition of a muon EDM was implemented in Geant4 to allow for simulating the experimental scheme. Secondly, the multiple Coulomb scattering of positrons in potential detector materials was measured to validate the simulations and to guide the design of the experiment. A reasonable agreement between measurements and simulation models has been confirmed. Finally, the beam characterisation of the potential beamlines to host the muon EDM experiment has been performed at the PSI µE1 and πE1 beamlines. The µ⁺ beam rate, transverse phase space (emittance) and beam polarisation level have been measured. This set the ground for beam injection studies and detailed simulation of the experiment. Moreover, as future prospects for the muon EDM experiment, the quality of the beam which will be delivered by a combination of the High-Intensity Muon Beams (HIMB), providing 10¹⁰surface µ⁺/s, and the muCool, a novel muon beam compression scheme, has been investigated with Geant4 simulations. The total compression efficiency and the beam quality of the HIMB-muCool beam have been updated

A Case of an 80-Year-Old Man with Empyema and Psoas Abscess

An 80-year-old man with flu symptoms collapsed at his house and had a backache worsened over time. His family called for an ambulance. On arrival, chest X-ray showed reduced permeability of the right lung field, and truncal computed tomography (CT) suggested right multilobular empyema and right iliopsoas abscess. A blood test showed an acute inflammatory response. The patient underwent right small thoracotomy for empyema and ultrasonic-guided drainage for the right iliopsoas abscess and started the administration of antibiotics. We started the administration of doripenem by intravenous drip and then deescalated to ampicillin based on the culture results. Streptococcus intermedius was cultured from all sites. Following these treatments for three months, his general condition improved. We herein report a unique case of complicated empyema and iliopsoas abscess in which a favorable outcome was obtained by an appropriate diagnosis and treatment. Reports of multiple abscesses have been increasing recently because of the growing geriatric population and aging-related complications. It is important to search the whole body to detect multiple abscesses in cases where an abscess is detected at a single site

Scintillation detectors with silicon photomultiplier readout in a dilution refrigerator at temperatures down to 0.2 K

We are developing a novel high-brightness atomic beam, comprised of a two-body exotic atom called muonium (M = μ + + e -), for next-generation atomic physics and gravitational interaction measurements. This M source originates from a thin sheet of superfluid helium (SFHe), hence diagnostics and later measurements require a detection system which is operational in a dilution cryostat at temperatures below 1 K. In this paper, we describe the operation and characterization of silicon photomultipliers (SiPMs) at ultra-low temperatures in SFHe targets. We show the temperature dependence of the signal shape, breakdown voltage, and single photon detection efficiency, concluding that single photon detection with SiPMs below 0.85 K is feasible. Furthermore, we show the development of segmented scintillation detectors, where 16 channels at 1.7 K and one channel at 170 mK were commissioned using a muon beam.ISSN:1748-022