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Biological nitrogen fixation (BNF) is important to sustain nitrogen fertility of paddy soil and rice yield, while could be affected by nitrogen fertilization. Iron-reducing bacteria, Anaeromyxobacter and Geobacter, are newly found diazotrophic bacteria predominant in paddy soil. Experimental field of this study is a long-term (35 years) nitrogen fertilized (6.0 g N/m 2 /year) and unfertilized paddy field, where ca. 70% of rice yield was obtained yearly in nitrogen unfertilized plot (443 ± 37 g/m 2 ) compared to fertilized plot (642 ± 64 g/m 2 ). Effects of long-term nitrogen fertilization/unfertilization on soil properties related to BNF were investigated with special reference to diazotrophic iron-reducing bacteria. Soil chemical/biochemical properties, soil nitrogen-fixing activity, and community composition of diazotrophic bacteria were similar between nitrogen fertilized and unfertilized plot soils. In both plot soils, Anaeromyxobacter and Geobacter were the most predominant diazotrophs. Their nifD transcripts were detected at similar level, while those of other general diazotrophs were under detection limit. It was concluded that long-term use/unuse of nitrogen fertilizer in this field did not affect the predominance and nitrogen-fixing activity of diazotrophic iron-reducing bacteria, composition of other general diazotrophs, and the resulting soil nitrogen-fixing activity. BNF, primarily driven by diazotrophic iron-reducing bacteria, might significantly contribute to sustain soil nitrogen fertility and rice yield in both plot soils. Appropriate soil management to maintain BNF, including diazotrophic iron-reducing bacteria, will be important for sustainable soil nitrogen fertility and rice production., (© 2023. The Author(s).)

Determination of radiopalladium 107 Pd is required to ensure radiation safety of the Pd extracted from spent nuclear fuel for recycling or disposal. We employed nanosecond laser ablation inductively coupled plasma quadrupole mass spectrometry (ns-LA-ICP-QMS) to simplify the analytical procedure of 107 Pd. Pd was separated through a selective Pd precipitation reaction induced by pulsed laser irradiation that reduces Pd(II) ions to metal Pd(0). Laser ablation facilitates direct measurement of the Pd precipitates, skipping the dissolution and dilution procedure with aqua regia and HCl, which causes serious corrosion damage to the introduction system of the ICP. In the present study, 102 Pd in natural Pd standard solution was used as an internal standard owing to its absence in spent nuclear fuel. Pd precipitates with diameters ranging from 0.2 to 0.5 μm, obtained by pulsed laser irradiation, were embedded uniformly on the surface of the centrifugal filter to form a microscopically thin and flat Pd surface. The resulting homogeneous Pd layer is suitable for obtaining a stable signal ratio of 107 Pd/ 102 Pd (< 4%, 2RSD). The mass bias-corrected ratio of 107 Pd/ 102 Pd and the amount of 107 Pd were 0.163 ± 0.004 and 17.8 ± 0.6 ng, respectively, which correspond to the values obtained by solution nebulization measurement after the dissolution of identical Pd precipitates. Graphical abstract ᅟ.

Purpose: The clinical impact of the coexistence of compressive cervical myelopathy (CM) and/or lumbar spinal canal stenosis (LCS) with compressive thoracic myelopathy (TM) remains unknown. The purpose of this study was to examine the incidence, clinical pictures, and surgical outcomes of patients with compressive TM and the coexistence of compressive CM and/or LCS., Methods: We retrospectively reviewed 50 patients (18 women and 32 men; mean age 68.4 years) who underwent decompression surgery for TM. Mean follow-up period was 44 months. The incidence and clinical features of the coexistence of CM and/or LCS were investigated. The surgical outcomes after single-stage multilevel decompression surgery were also examined using the Japanese Orthopedic Association (JOA) scores., Results: Of 50 patients, 35 had concurrent CM and/or LCS (combined group), and the remaining 15 only had TM (T group). No significant differences were found with regard to sex, the etiology of TM, or the level of thoracic stenosis between the groups; however, the patients' age and preoperative JOA scores in the combined group were significantly higher than those in the T group. In both groups, the JOA score at the final follow-up significantly improved compared to the preoperative JOA score., Conclusions: About 70 % of patients who underwent surgery for TM had concurrent CM and/or LCS, and they were initially diagnosed with CM or LCS. Single-stage multilevel decompression surgery for TM with concurrent CM and/or LCS is comparable to thoracic only surgery with regard to complications and surgical results, and it is well tolerated in elderly patients.

Introduction: Several magnetic resonance (MR) imaging techniques are used to examine atherosclerotic plaque of carotid arteries; however, the best technique for visualizing intraplaque characteristics has yet to be determined. Here, we directly compared four kinds of T1-weighted (T1W) imaging techniques with pathological findings in patients with carotid stenosis., Methods: A total of 31 patients who were candidates for carotid endarterectomy were prospectively examined using a 1.5-T MRI scanner, which produced four kinds of T1W images, including non-gated spin echo (SE), cardiac-gated black-blood (BB) fast-SE (FSE), magnetization-prepared rapid acquisition with gradient echo (MPRAGE), and source image of three-dimensional time-of-flight MR angiography (SI-MRA). The signal intensity of the carotid plaque was manually measured, and the contrast ratio (CR) against the adjacent muscle was calculated. CRs from the four imaging techniques were compared to each other and correlated with histopathological specimens., Results: CRs of the carotid plaques mainly containing fibrous tissue, lipid/necrosis, and hemorrhage were significantly different with little overlaps (range: 0.92-1.15, 1.22-1.52, and 1.55-2.30, respectively) on non-gated SE. However, BB-FSE showed remarkable overlaps among the three groups (0.89-1.10, 1.07-1.23, and 1.01-1.42, respectively). MPRAGE could discriminate fibrous plaques from hemorrhagic plaques but not from lipid/necrosis-rich plaques: (0.77-1.07, 1.45-2.43, and 0.85-1.42, respectively). SI-MRA showed the same tendencies (1.01-1.39, 1.45-2.57, and 1.12-1.39, respectively)., Conclusion: Among T1W MR imaging techniques, non-gated SE images can more accurately characterize intraplaque components in patients who underwent CEA when compared with cardiac-gated BB-FSE, MPRAGE, and SI-MRA images.

Introduction: Cilostazol, an antiplatelet agent, is reported to induce the regression of atherosclerotic changes. However, its effects on carotid plaques are unknown. Hence, we quantitatively investigated the changes that occur within carotid plaques during cilostazol administration using three-dimensional (3D) ultrasonography (US) and non-gated magnetic resonance (MR) plaque imaging., Methods: We prospectively examined 16 consecutive patients with carotid stenosis. 3D-US and T1-weighted MR plaque imaging were performed at baseline and 6 months after initiating cilostazol therapy (200 mg/day). We measured the volume and grayscale median (GSM) of the plaques from 3D-US data. We also calculated the contrast ratio (CR) of the carotid plaque against the adjacent muscle and areas of the intraplaque components: fibrous tissue, lipid, and hemorrhage components., Results: The plaque volume on US decreased significantly (median at baseline and 6 months, 0.23 and 0.21 cm(3), respectively; p = 0.03). In the group exhibiting a plaque volume reduction of more than 10%, GSM on US increased significantly (24.8 and 71.5, respectively; p = 0.04) and CR on MRI decreased significantly (1.13 and 1.04, respectively; p = 0.02). In this group, in addition, the percent area of the fibrous component on MRI increased significantly (68.6% and 79.4%, respectively; p = 0.02), while those of the lipid and hemorrhagic components decreased (24.9% and 20.5%, respectively; p = 0.12) (1.0% and 0.0%, respectively; p = 0.04). There were no substantial changes in intraplaque characteristics in either US or MRI in the other group., Conclusions: 3D-US and MR plaque imaging can quantitatively detect changes in the size and composition of carotid plaques during cilostazol therapy.

Introduction: Magnetic resonance (MR) plaque imaging for carotid arteries is usually performed by using an electrocardiograph (ECG)-gating technique to eliminate pulsation-related artifacts, which can affect the plaque signals because of varied repetition time (TR) among patients. Hence, we investigated whether differences in TR causes signal alterations of the carotid plaque by using a non-gated plaque imaging technique., Methods: We prospectively examined 19 patients with carotid stenosis by using a T1-weighted self-navigated radial-scan technique with TRs of 500, 700, and 900 ms. The signal intensity of the carotid plaque was measured, and the contrast ratio (CR) relative to the adjacent muscle was calculated., Results: CRs of the carotid plaques were 1.39 +/- 0.39, 1.29 +/- 0.29, and 1.23 +/- 0.24 with TRs of 500, 700, and 900 ms, respectively, and were significantly different. Among the plaques, those with a hyperintensity signal (CR > 1.5) and moderate-intensity signal (CR 1.2-1.5) at 500 ms showed a TR-dependent signal decrease (hyperintensity plaques, 1.82 +/- 0.26; 1.61 +/- 0.19; and 1.48 +/- 0.17; moderate-intensity plaques, 1.33 +/- 0.08; 1.26 +/- 0.08; and 1.19 +/- 0.07), while those with an isointensity signal (CR < 1.2) remained unchanged regardless of TR (0.96 +/- 0.12, 0.96 +/- 0.11, and 0.97 +/- 0.13)., Conclusion: The signal intensity of the carotid plaque on T1-weighted imaging significantly varies among different TRs and tends to decrease with longer TR. MR plaque imaging with short and constant TR settings that the ECG-gating method cannot realize would be preferable for evaluating plaque characteristics.

Introduction: The aim of this study was to determine the performance of axial and coronal magnetic resonance imaging (MRI) in detecting the narrowing of the cerebrospinal fluid (CSF) space at the high convexity and high midline areas, which is speculated to be one of the clinical characteristics of idiopathic normal pressure hydrocephalus (iNPH)., Methods: We retrospectively examined axial and coronal T1-weighted images of 14 iNPH patients and 12 age-matched controls. The narrowness of the CSF space at the high convexity/midline was blindly evaluated by five raters using a continuous confidence rating scale for receiver operating characteristic (ROC) analysis., Results: Axial and coronal imaging accurately determined the presence of the narrow cisterns/sulci at the high convexity/midline and was capable of predicting probable/definite iNPH with a high degree of accuracy. there were also no significant differences in the detection of this finding between the axial and coronal images., Conclusion: Both axial and coronal T1-weighted MRI can detect the narrow CSF space at the high convexity/midline accurately and may therefore facilitate clinicians in choosing a management strategy for iNPH patients.

The product of the BLM gene, which is mutated in Bloom syndrome in humans, and the Saccharomyces cerevisiae protein Sgs1 are both homologous to the Escherichia coli DNA helicase RecQ, and have been shown to be involved in the regulation of homologous recombination. Mutations in these genes result in genome instability because they increase the incidence of deletions and translocations. We present evidence for a genetic interaction between SGS1 and YKU70, which encodes the S. cerevisiae homologue of the human DNA helicase Ku70. In a yku70 mutant background, sgs1 mutations increased sensitivity to DNA breakage induced either by treatment with camptothecin or by the expression of the restriction enzyme EcoRI. The yku70 mutation caused a fourfold increase in the rate of double-strand break (DSB)-induced target integration as that seen in the sgs1 mutant. The combination of yku70 and sgs1 mutations additively increased the rate of the targeted integration, and this effect was completely suppressed by deletion of RAD51. Interestingly, an extra copy of YKU70 partially suppressed the increase in targeted integration seen in the sgs1 single mutant. These results suggest that Yku70 modulates the repair of DSBs associated with homologous recombination in a different way from Sgs1, and that the inactivation of RecQ and Ku70 homologues may enhance the frequency of gene targeting in higher eukaryotes.

Magnetic resonance (MR) features of five primary malignant mesenchymal neoplasms (plasmocytoma, leiomyosarcoma, undifferentiated sarcoma, epithelioid hemangioendothelioma, and angiosarcoma) of the liver were reported. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. No halo and intravenous extension were noted. A target appearance was revealed in epithelioid hemangioendothelioma. MR findings of angiosarcoma were essentially the same as those of cavernous hemangiomas (markedly hyperintense with hypointense linear septa on T2-weighted images). MR findings of these rare hepatic malignancies were nonspecific, although they were quite different from those of typical hepatocellular carcinomas. This study suggested that MR differentiation of primary hepatic mesenchymal tumors from other common benign and malignant neoplasms was difficult; however, the number of studied cases was limited.

Direct communication between portal branches and the hepatic vein [macroscopic intra-hepatic portal-hepatic venous shunt (IPHVS)] is a rare entity. We have recently studied five patients with this condition. Magnetic resonance imaging (MRI) clearly demonstrated in each case the portal-hepatic venous shunt due to "flow void." Multiple diffuse shunts were present in one case and a solitary shunt was demonstrated in the others. The solitary shunt was either tubular, focally dilated or racemose in configuration. The MRI findings and clinical significance of this rare entity are discussed.