Hokkaido University

About: Hokkaido University is a education organization based out in Sapporo, Hokkaidô, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 53925 authors who have published 115403 publications receiving 2651647 citations. The organization is also known as: Hokudai & Hokkaidō daigaku.

Comparison of bone scintigraphy and 68 Ga-PSMA PET for skeletal staging in prostate cancer

Abstract: The aim of our study was to compare the diagnostic performance of 68Ga-PSMA PET and 99mTc bone scintigraphy (BS) for the detection of bone metastases in prostate cancer (PC) patients. One hundred twenty-six patients who received planar BS and PSMA PET within three months and without change of therapy were extracted from our database. Bone lesions were categorized into benign, metastatic, or equivocal by two experienced observers. A best valuable comparator (BVC) was defined based on BS, PET, additional imaging, and follow-up data. The cohort was further divided into clinical subgroups (primary staging, biochemical recurrence, and metastatic castration-resistant prostate cancer [mCRPC]). Additionally, subgroups of patients with less than 30 days delay between the two imaging procedures and with additional single-photon emission computed tomography (SPECT) were analyzed. A total of 75 of 126 patients were diagnosed with bone metastases. Sensitivities and specificities regarding overall bone involvement were 98.7–100 % and 88.2–100 % for PET, and 86.7–89.3 % and 60.8–96.1 % (p < 0.001) for BS, with ranges representing results for ‘optimistic’ or ‘pessimistic’ classification of equivocal lesions. Out of 1115 examined bone regions, 410 showed metastases. Region-based analysis revealed a sensitivity and specificity of 98.8–99.0 % and 98.9–100 % for PET, and 82.4–86.6 % and 91.6–97.9 % (p < 0.001) for BS, respectively. PSMA PET also performed better in all subgroups, except patient-based analysis in mCRPC. Ga-PSMA PET outperforms planar BS for the detection of affected bone regions as well as determination of overall bone involvement in PC patients. Our results indicate that BS in patients who have received PSMA PET for staging only rarely offers additional information; however, prospective studies, including a standardized integrated x-ray computed tomography (SPECT/CT) protocol, should be performed in order to confirm the presented results.

Luminescence Ranging from Red to Blue: A Series of Copper(I)−Halide Complexes Having Rhombic {Cu2(μ-X)2} (X = Br and I) Units with N-Heteroaromatic Ligands

Abstract: A series of Cu(I) complexes formulated as [Cu2(μ-X)2(PPh3)(L)n] were prepared with various mono- and bidentate N-heteroaromatic ligands (X = Br, I; L = 4,4‘-bipyridine, pyrazine, pyrimidine, 1,5-naphthyridine, 1,6-naphthyridine, quinazoline, N,N-dimethyl-4-aminopyridine, 3-benzoylpyridine, 4-benzoylpyridine; n = 1, 2). Single-crystal structure analyses revealed that all the complexes have planar {Cu2X2} units. Whereas those with monodentate N-heteroaromatic ligands afforded discrete dinuclear complexes, bidentate ligands formed infinite chain complexes with the ligands bridging the dimeric units. The long Cu···Cu distances (2.872−3.303 A) observed in these complexes indicated no substantial interaction between the two Cu(I) ions. The complexes showed strong emission at room temperature as well as at 80 K in the solid state. The emission spectra and lifetimes in the microsecond range were measured at room temperature and at 80 K. The emissions of the complexes varied from red to blue by the systematic sele...

Impacts of wildfire on the permafrost in the boreal forests of Interior Alaska

Abstract: [1] The impact to the permafrost during and after wildfire was studied using 11 boreal forest fire sites including two controlled burns. Heat transfer by conduction to the permafrost was not significant during fire. Immediately following fire, ground thermal conductivity may increase 10-fold and the surface albedo can decrease by 50% depending on the extent of burning of the surficial organic soil. The thickness of the remaining organic layer strongly affects permafrost degradation and aggradation. If the organic layer thickness was not reduced during the burn, then the active layer (the layer of soil above permafrost that annually freezes and thaws) did not change after the burn in spite of the surface albedo decrease. Any significant disturbance to the surface organic layer will increase heat flow through the active layer into the permafrost. Approximately 3–5 years after severe disturbance and depending on site conditions, the active layer will increase to a thickness that does not completely refreeze the following winter. This results in formation of a talik (an unfrozen layer below the seasonally frozen soil and above the permafrost). A thawed layer (4.15 m thick) was observed at the 1983 burned site. Model studies suggest that if an organic layer of more than 7–12 cm remains following a wildfire then the thermal impact to the permafrost will be minimal in the boreal forests of Interior Alaska.

Abnormal asymmetries in subcortical brain volume in schizophrenia.

Abstract: Subcortical structures, which include the basal ganglia and parts of the limbic system, have key roles in learning, motor control and emotion, but also contribute to higher-order executive functions. Prior studies have reported volumetric alterations in subcortical regions in schizophrenia. Reported results have sometimes been heterogeneous, and few large-scale investigations have been conducted. Moreover, few large-scale studies have assessed asymmetries of subcortical volumes in schizophrenia. Here, as a work completely independent of a study performed by the ENIGMA consortium, we conducted a large-scale multisite study of subcortical volumetric differences between patients with schizophrenia and controls. We also explored the laterality of subcortical regions to identify characteristic similarities and differences between them. T1-weighted images from 1680 healthy individuals and 884 patients with schizophrenia, obtained with 15 imaging protocols at 11 sites, were processed with FreeSurfer. Group differences were calculated for each protocol and meta-analyzed. Compared with controls, patients with schizophrenia demonstrated smaller bilateral hippocampus, amygdala, thalamus and accumbens volumes as well as intracranial volume, but larger bilateral caudate, putamen, pallidum and lateral ventricle volumes. We replicated the rank order of effect sizes for subcortical volumetric changes in schizophrenia reported by the ENIGMA consortium. Further, we revealed leftward asymmetry for thalamus, lateral ventricle, caudate and putamen volumes, and rightward asymmetry for amygdala and hippocampal volumes in both controls and patients with schizophrenia. Also, we demonstrated a schizophrenia-specific leftward asymmetry for pallidum volume. These findings suggest the possibility of aberrant laterality in neural pathways and connectivity patterns related to the pallidum in schizophrenia.

Marginal adaptation of a restorative resin polymerized at reduced rate.

Abstract: — The aim of this study was to investigate the effect of reduced rate of polymerization on the marginal adaptation of a composite resin inserted in dentin cavities treated with a simplified Gluma system. The effect on bonding strength to dentin and compressive strength was also investigated. The light intensity of the polymerization unit was lowered by the use of a transformer, and thus the rate of polymerization of the composite resin. When the resin was irradiated for 30 s at 110 V followed by 30 s at 220 V, the marginal adaptation was significantly improved. This condition resulted in acceptable values of bonding strength to dentin and diametral compressive strength. It is suggested that the reduced rate of polymerization may allow for increased flow of the material, decreasing the contraction stress in the filling.