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No previous research papers have reported a comparative survey of local radiologic diagnoses and central review in children with hepatoblastoma.To evaluate the utility of central review of children with hepatoblastoma enrolled in a clinical trial.The study included 91 children enrolled in a clinical trial conducted by the Japanese Study Group for Pediatric Liver Tumor. We compared the results of the initial pre-treatment extent of tumor (PRETEXT) disease staging performed at local sites with the results obtained on central review to determine the concurrence rates for tumor staging and additional criteria.The concurrence rate for PRETEXT staging was 70%. As the stage increased, the concurrence rate decreased. Using additional criteria, central review identified 143 lesions (157.1%), about 1.8 times higher than the number identified for the local site diagnoses. The additional criterion found most often on central review was "multifocal lesion" (n=19). The concurrence rate for lung metastases was high. However, our central review found many false-positive assertions of hepatic vein lesions, portal vein invasion and extrahepatic lesions among the local site diagnoses.In a clinical trial of hepatoblastoma, central review provided a more precise diagnosis than local site diagnoses with respect to severe PRETEXT stages III and IV cases and other cases including hepatic and portal vein invasion. The central review process appears to be effective and essential for improving the quality of clinical trials.

Neuroblastoma is the most common extracranial solid tumor in children. When metastasis to the falx cerebri is present, it is classified as stage M; however, its behavior has not been well characterized. Here we present a case of stage M infantile neuroblastoma (NB) with involvement of the falx cerebri, and also summarize the clinical profiles of previously reported cases. Notably, all of the tumors resolved with low-dose chemotherapy alone. Although further study is needed to distinguish NBs presenting at these different intracranial locations, NB with metastasis to the falx cerebri may be categorized as MS when diagnosed at less than 18 months of age.

Tracheal atresia causes some secondary changes (dilated trachea, flattened/inverted diaphragm, hyperintense and hyperinflated lungs). They can be reduced if a high airway fistula is present. This study evaluated fetal MR images of tracheal atresia and the secondary changes, focusing on the presence of a fistula. We assessed fetal MR images of tracheal atresia without fistula (n=4, median 26 weeks), tracheal atresia with fistula (n=4, median 33 weeks) and controls (n=30, median 32 weeks). We evaluated airway obstruction using true-positive rate in tracheal atresia and false-positive rate in controls indicating they are likely normal variants. Tracheal diameter, craniocaudal-anteroposterior ratio of the right hemidiaphragm, lung-to-liver signal intensity ratio, and cardiothoracic ratio were compared among the three groups using the Kruskal-Wallis test followed by pairwise comparison using the Mann-Whitney U test. True-positive rate was 100% in tracheal atresia, while false-positive rate was 20% in controls. The Kruskal-Wallis test showed differences among groups in craniocaudal-anteroposterior ratio and cardiothoracic ratio (P

Background The precise time of appearance of bone marrow edema in acute hematogenous pelvic osteomyelitis (AHPO) is unknown. The purpose of present research is to clarify the time of appearance of bone marrow edema on MRI in AHPO. Our hypothesis was that onset is slower than in long-bone osteomyelitis. Methods We selected twelve patients (mean, 11.8 years) with MRI findings and clinical diagnosis of AHPO. The signal ratios of bone marrow (BM) and gluteus maximus muscle (M, BM/M ratio) in fat-suppressed T2- and T1-weighted images (T2WI, T1WI) were calculated to evaluate changes in bone marrow signals. The correlation between BM/M ratios and days from onset was statistically evaluated and compared to lower extremity osteomyelitis. Results BM/M ratio of T2WI increased over time after onset of the primary symptom in all patients and showed a statistically positive correlation (r = 0.36). In seven patients in whom an MRI scan was conducted twice, all showed higher values for the second MRI, and changes were more pronounced over time. The mean BM/M ratio of T2WI was 4.1 when seven days or less had elapsed from the primary symptom and 6.4 when more than seven days had elapsed . BM/M ratios in the sacroiliac joint group were lower than in the non-sacroiliac joint group. Conclusion Unlike long-bone osteomyelitis, it took one week before findings for AHPO became fully evident. A definitive diagnosis can be made in patients with suspected sacroiliitis by performing a further MRI scan at seven days or later.

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare neuroendocrine tumors that arise from chromaffin cells. We report the case of an 11-year-old boy with no history of hypertension who presented with an abdominal mass arising from the retroperitoneum. During laparoscopic surgery, the patient developed a hypertensive crisis with a peak systolic blood pressure of over 270 mmHg, although we were able to continue to perform laparoscopic resection. Even if no concomitant symptoms due to catecholamine production are observed before surgery, as in this case, blood pressure may fluctuate during surgery. Intraoperative and postoperative management should be considered in cooperation with anesthesiologists.

A two-year-old girl presented with an abdominal mass, abdominal pain, and fever. A quail egg-sized elastic-hard mass was palpable in the upper left abdomen. The patient's growth was impaired. Laboratory data showed an inflammatory response and elevated pancreatic enzymes. The mass showed a cystic structure adjacent to the caudal side of the bifid tail of the pancreas. A fluid collection was observed around the spleen. Surgery was planned under the diagnosis of pancreatic foregut cystic malformation (FCM) associated with a bifid pancreatic tail. However, as the inflammation worsened, parenteral nutrition (PN) was introduced and cyst drainage was performed first, obtaining 10–14 mL/day, and her symptoms subsided. Cyst drainage continued for six weeks at home. Laparoscopic surgery was performed 47 days after the initiation of drainage. Cystography showed communication between the cyst and the slightly dilated pancreatic duct of the bifid tail during surgery. A partial pancreatectomy with cystectomy was performed. The diagnosis of FCM originating from the pancreas, associated with the bifid tail, was confirmed. The postoperative course was uneventful, and the patient was discharged eight days post-surgery. Pancreatic FCM with a bifid pancreatic tail is rare, and we successfully treated it using minimally invasive surgery.

Detecting an aberrant artery is the key to diagnosing bronchopulmonary sequestration (BPS) on fetal MRI. Few reports describe the best sequence to use for this purpose. We compared visualization of an aberrant artery in BPS on fetal MRI using single-shot turbo spin echo (SSTSE) and balanced steady state free precession (b-SSFP) sequences. We retrospectively reviewed the fetal MRI of 27 fetuses in which BPS was diagnosed prenatally (2003–2016). From these we selected 15 fetuses with the pathological diagnosis of BPS made postnatally at operation. All fetuses were examined in 1.5 T MRI units using SSTSE and b-SSFP sequences (mean gestational age: 28.4 ± 3.4 weeks). Two pediatric radiologists compared visualization of the aberrant artery using the two sequences. The presence of an aberrant artery was confirmed by postnatal contrast-enhanced CT. The influence of arterial diameter and background heterogeneity of the lung on the diagnostic power was also evaluated. All 15 fetuses clearly showed the aberrant artery on the SSTSE sequence. Conversely, the aberrant arteries detected on the SSTSE sequence were absent in the b-SSFP sequences of eight fetuses, and the other seven fetuses showed ambiguous visualization compared with the SSTSE sequence. Arterial diameter and background heterogeneity did not affect the diagnostic power in either sequence. The SSTSE sequence was superior to the b-SSFP sequence for clear visualization of the aberrant artery in BPS, regardless of the arterial diameter and background heterogeneity.

Ovary detection is the first step in confirming ovarian lesions. The daughter cyst sign is widely used for this purpose; however, it is not always applicable. Recent improvements in image resolution allow Fallopian tube delineation, which can serve as a guide to identify the ovary. This anatomical approach ("follow the Fallopian tube" technique) comprises three steps: (1) confirm the uterus; (2) follow the Fallopian tube; and (3) find the ovary. Other applications of this approach include the differentiation between nonovarian and ovarian masses and ruling out ovarian torsion and an auto-amputated ovary.

The Federation of Electric Power Companies (FEPC) of Japan has long been releasing the detailed financial statements of their member corporations (on their web site). We have analyzed the FEPC’s financial data over half a century and have clarified the problems and distortions built in Japan’s power industry through the ‘dual pricing mechanism’ for the “industrial use” and the “home-use” sectors. In fact the former shares two thirds of the power demand and yields only small profits or even losses; and the latter, sharing one third of the demand, yields nearly all of the industry’s profits. After the full retail deregulation, however, this home-use sector (the industry’s treasure box) seems now suffering diminution of profitability: because the power majors have began to raise a “cutthroat competition” against each other. This price-cutting war might be considered very dangerous for the sustainability of this industry because this business is highly equipment-intensive and so severely vulnerable to any revenue instability.Keywords: Electricity demand, Dualistic pricing, Income statement, Power retail deregulationJEL Classifications: M4, L5, L9, Q4DOI: https://doi.org/10.32479/ijeep.6999

The Federation of Electric Power Companies (FEPC) of Japan has long been releasing the detailed financial statements of their member corporations (on their website). We have analyzed the transition of Japan's electric power policy through the business structure of the electric power industry using the FEPC financial data over 53 years. Thus, we have clarified the problems and distortions built into the power industry by Japan's power policy as stated in the following: (1) During the regulation period, the dual-price mechanism for the industrial use and the home-use sectors had been effectuated, where (2) the former shared two thirds of the power demand but yielded only small profits or even losses; and the latter, sharing only one third of the demand, yielded nearly all of the industry's profits; however, (3) since the start of complete retail deregulation, this dual-price mechanism has come to suffer paralysis and the power majors began a cutthroat competition, which now seems to result in diminution of profitability in the home-use sector (the industry's former treasure box). This price-cutting war is considered very dangerous for the sustainability of this industry because this business is highly equipment-intensive and is severely vulnerable to any revenue instability. Meanwhile, declining demand due to the declining population is inevitable, and the power infrastructure will become excessively capacitive against demand. At the policy level of the government, recognition to this is overwhelmingly short. There is a possibility that the most powerful risk of both the electric power industries and social economy will be the way of the electric power policy that leads electricity demand from the expected growth rate and prepares the power supply configuration based on it.

BACKGROUND Congenital unilateral pulmonary vein atresia (CUPVA) is known to lead to the formation of an abnormal confluent mediastinal and hilar soft tissue mass, thoracic hypoplasia, and interlobular septal thickening on the affected side. The purpose of the present study is to investigate the frequency and severity of mediastinal soft tissue mass-like lesions and examine other abnormal findings associated with CUPVA. METHODS We retrospectively reviewed seven children with CUPVA who underwent contrast-enhanced CT scans and measured the soft tissue mass volume in the bilateral mediastinum (affected and normal side). The location of abnormal soft tissue was divided into three anatomical sections (paratracheal, peribronchial, and the dorsal aspect of the left atrium). The relationships among soft tissue volume and anatomical section were statistically evaluated. Also, the presence of thoracic hypoplasia, small ipsilateral pulmonary arteries, interlobular septal thickening, and ground-glass opacities were investigated. RESULTS In all cases, CT scans confirmed the presence of confluent soft tissue mass-like lesions in the affected mediastinum. The soft tissue volume on the affected side was 5.5-fold greater than the volume on the normal side (average: 18.0 cm3 and 4.25 cm3 respectively, P < 0.01). Thoracic hypoplasia and interlobular septal thickening were found in all patients. Small pulmonary arteries and ground-glass opacities were present in six of the seven patients. CONCLUSION Abnormal mediastinal and hilar soft tissue is commonly found in patients with CUPVA. So, if we encounter the mediastinal soft tissue mass in patients with CUPVA, no further test will be indicated.

Since currency is a means of exchange, it forms a standard of value. Modern economics uses the function of currency as a &ldquo, general standard of value&rdquo, and describes the economic processes in the terms of value by the quantity of money. The most notable indicator to symbolize this situation is &ldquo, Gross Domestic Product&rdquo, (GDP). However, GDP, in general, does not indicate the economic process as a whole. It is necessary to add intermediate inputs to the GDP in order to calculate the total amount of industrial output of a country, and this total industrial output can never realize without energy supply. In other words, the total industrial output of a country and the total amount of energy supplied (= consumed) constitute an inseparable relationship like the front and back of the coin. This research tries to propose an alternative evaluation indicator based on &ldquo, energy&rdquo, which is the most important economic substance and the indispensable requirement for all human activities. Regarding this issue, this study deals with the following problems. First, we refer to a dualistic composition which Soddy had adopted, from the beginning, to classify wealth, which is a product of economic processes, into two categories: one on a physical dimension (Wealth I &middot, II) and the other on a psychological dimension (Virtual Wealth). Then, based on the dualistic framework proposed by Soddy, we present that we can evaluate the economic process, through a compound-eye view, on two dimensions: the physical dimension (energy flow) and the institutional dimension (money flow). Next, we focus on &lsquo, the economic process presented by monetary value&rsquo, (A) and &lsquo, the energy quantity which effectually supports this process&rsquo, (B). We have introduced how to project (B) onto the constituent elements of (A). Thus, we take a case study on Japan by use of dualistic aspects approach.

The prognosis of diffuse intrinsic pontine glioma (DIPG) remains dismal. The only effective treatment is radiation therapy so far. Nevertheless, the therapeutic effect of radiation therapy doesn’t last for long and almost all the patients experience relapse after several months. Recently, re-irradiation for relapsed DIPG was attempted and showed some benefit for those patients. We retrospective reviewed the efficacy and safety of re-irradiation therapy for five DIPG cases from April 2013 to December 2017. Five patients include three boys and two girls, their mean age was 7.2 years old (4–12). One case only did biopsy for diagnosis, others diagnosed clinically. One case underwent ventricular Ommaya reservoir insertion due to hydrocephalus. Radiation doses were from 19.8Gy to 50.4Gy(1.8–3.0Gy/Fr). The median duration between diagnosis and recurrence was 7.5 months (4–10 months), and the mean survival after the re-irradiation was 6.3 months (two of them still surviving). All five patients completed the treatment without acute toxicity, and four out of five patients demonstrated some improvement of their symptoms which occurred at the recurrence. It has been suggested that re-irradiation might be an effective and safe treatment for selected patients with recurrent DIPG.

Atypical teratoid rhabdoid tumors (AT/RTs) are highly aggressive embryonal CNS tumors. Up to one-third of AT/RTs are reported to have germline mutation and/or deletion of SMARCB1/hSNF5. In accordance with the increased understanding for pediatric cancer predisposition syndrome, the needs for genetic counseling and testing is expanding. And next generation suquencing technique is inevitable for these genotyping. So we start to prepare genetic testing system of AT/RT for future pediatric cancer predisposition program. Proior to the genetic testing, pretest counseling is performed for each patient/family. Informed consent was obtained according to the institutional ethical review board. Genomic DNA was isolated from the patient’s periphera blood, and somatic DNA was extracted from frozen tissues or FFPE samples. Genetic analysis of the SMARCB1 coding sequence was performed by Sanger method. Deletion of SMARCB1 is examined by quantitative analysis of each exon with droplet digital PCR (ddPCR). SNP array analysis is also tried if frozen sample is available. Three AT/RT patients and one rhabdoid tumor patient received genetic testing. None of them had germline mutation. In an infant ATRT, Sanger sequence analysis revealed frameshift mutation (c649-650delAT). Also, ddPCR showed uniparenteral heterodisomy (UPD). In another AT/RTs, copy number decrease and UPD over whole region of SMARCB1, or exon 3 deletion are recognized respectively. Rhabdoid tumor case had nonsense mutation (c610C>T). Although most of AT/RT should have biallelic mutation, false negative could happen due to less tumor cells obtained in those samples. Enlightenment for sampling and accumulation for testing would be important.

The treatment of choice for young children with unresectable low grade gliomas (LGG) that occur in the optic nerve, deep midline cerebrum or, brainstem is chemotherapy. Carboplatin and vincristine, or vinblastine are most widely used, and in many cases, tumor control can be obtained safely, but the recurrence rate is high and the symptom may progress. Recently, successful treatment with pediatric LGG by bevacizumab, a monoclonal antibody against vascular endothelial cell growth factor has been reported. Here, we report our experience of bevacizumab treatment for 6 children with unresectable LGG. Mean age at bevacizumab treatment was 6y9m (3y11m-8y4m). Histopathological diagnoses were Pilocytic astrocytoma (2 patients), LGG NOS (2), glioneuronal tumor NOS (1) and no pathology (1). Two patients had neurofibromatosis type 1. The median total doses of bevacizumab in patients who completed the treatment were 10 courses (10-16). The indications for bevacizumab treatment were tumor enlargement (3), amblyopia (2) and homonymous hemianopsia (1). The only observed adverse event was proteinuria in 1 patient. Five out of 6 patients demonstrated decrease of tumor size. Among 4 patients with visual abnormalities, improvement of amblyopia was observed in 1 patient and vision was stabilized in other 3 patients. Bevacizumab treatment for pediatric LGG patients was safe, showed anti-tumor effect and contributed to stabilization of vision.

We have performed the detailed measurements of temperature dependence of magnetization M ( T ) on MgB 2 single crystals in a wide range of field H using torque magnetometry. In a field region, where the peak effect in M ( H ) is observed, we find that M ( T ) of the warming branch increases monotonously with T and exhibits a small step-like increase at T 1 ∗ , which is related to the order–disorder transition, while M ( T ) of the cooling branch, showing the larger values than that in warming branch below T 1 ∗ , drops suddenly toward the warming branch at T 2 ∗ . We ascribe this anomalous behavior of M ( T ) of the cooling branch to a supercooling phenomenon of disordered phase, which transforms to the ordered state at T 2 ∗ .

We have studied the order–disorder transition in high quality MgB 2 single crystals, using a torque magnetometry combined with a ‘vortex shaking’ technique. In the wide range of temperature T , field H and the H direction, we succeed in obtaining reversible magnetization curves M rev ( T , H ) by shaking the pinned vortices. Especially at low temperatures below 25 K and high fields, where the irreversible magnetization curve exhibits the peak effect due to the order–disorder transition, it is found that the peak is transformed into the clear step in M rev ( H ). Similar step-like behavior is also observed in the temperature dependence of magnetization M rev ( T ). These results give direct evidence that the order–disorder transition, which is hidden by the large hysteresis of magnetization, has the nature of first-order transition.

The vortex matter phase transitions and intrinsic pinning effect were investigated in an MgB 2 single crystal using the torque magnetometry. For the field directions apart from the ab plane, we succeed in the observation of the vortex lattice melting transitions, which are transformed from the order–disorder transitions at low temperatures. Both transition fields with field directions can be describe by the GL effective mass model. For the field direction along the ab plane, these transitions become unobservable. Instead, the sudden increase in the hysteresis of magnetization curve occurs, indicating the existence of the intrinsic pinning coming from the layer structure.

Full varieties of strongly correlated electron phenomena have been found in the filled skutterudite systems, by changing the constituent elements. The unique crystal structure leads to novel features even in the systems containing rare earth elements with plural number of 4 f -electrons. According to the intensive competitions and cooperation among experimental and theoretical research works, remarkable progress has been made in sorting out several basic origins that bring about the variety of this system, such as the strong c – f hybridization, the small CEF level splitting, the orbital degree of freedom (multipoles), and the positional degree of freedom within a pnictogen cage. However, there still remain many attractive questions to be answered.

The experimental field-dependent specific heat of the polydomain pure Yb4As3 and diluted (Yb1−xLux)4As3 (x = 0.01, 0.03) systems is presented and compared with that calculated by the numerical quantum transfer-matrix method. The simulations have been performed using the S = 1/2 antiferromagnetic Heisenberg model with the transverse staggered field (appearing as a result of the antisymmetric Dzyaloshinskii–Moriya interaction) and a uniform magnetic field perpendicular to the staggered field. In the model calculations the fixed microscopic parameters have been taken and the impurity distribution has been considered. A significant improvement with respect to the previous results is shown.

In the filled skutterudite compounds (RT 4 X 12 : R rare earth, T=Fe, Ru, Os, and X=pnictogen-ions), various attractive features have been found by replacing the constituent elements, e.g., metal–insulator transition in PrRu 4 P 12 , competing heavy fermion and multipolar ordered states in PrFe 4 P 12 , heavy fermion superconductivity in PrOs 4 Sb 12 , etc. Most of these features are realized probably by the unique crystal structure; R is embedded in the cage made of 12X and eight T ions, so that the strong c–f hybridization becomes a common feature irrespective of the constituent elements. The strong c–f hybridization in skutterudites enables the strongly correlated electron behaviors even in the systems containing rare-earth elements with more than one 4f-electron. The effect of X-replacement appears most apparently as a change in c–f hybridization, as is naturally inferred from the large difference in lattice constant. In addition to the c–f hybridization effect, it was recognized that f-electron's multipolar degrees of freedom and relatively small crystalline electric field splitting are important factors to understand the aforementioned novel phenomena.

We present the temperature--pressure--magnetic-field phase diagram of the itinerant-electron metamagnet UCoAl determined from the ac susceptibility measurement. The quantum critical point (QCP) was found to be located at $2.9\ifmmode\pm\else\textpm\fi{}0.2$ GPa ($\ensuremath{\equiv}{P}_{\mathrm{QCP}}$) and $130\ifmmode\pm\else\textpm\fi{}5$ kOe. In addition to the determination of the phase diagram, we report magnetic and transport properties in the paramagnetic state and around the phase boundary. The critical divergence of the magnetic susceptibility is suppressed toward the QCP. From the longitudinal magnetoresistance and the resistivity under magnetic fields, enhancement of the resistivity is observed in the so-called supercritical region. In the paramagnetic region, the magnetoresistance and temperature dependence of the resistivity exhibit complex behaviors, especially in the vicinity of 1.5 GPa and ${P}_{\mathrm{QCP}}$.

The field dependence of anisotropy in the mixed state of MgB 2 single crystals is studied using torque magnetometry. At all temperatures measured, the anisotropy parameter γ , derived from the angular dependence of magnetic torque τ , increases with increasing field H and shows a plateau with a almost constant value of ∼4.5, indicating that the isotropic π band contribution to the superconductivity weakens with H and only the anisotropic σ band contribution remains in the plateau region. In the low field region below the plateau, we found a change in the functional form of γ ( H ) at H = H * . In addition, the step-like decrease in the H dependence of d( τ / H )/d H is observed at H * . These anomalies can be related to the change in the vortex lattice structure accompanied by the decrease of the π band contribution.

A general survey of the variety of phenomena exhibited by the filled skutterudite compounds is presented from the view points of electrical properties and electronic structure, putting emphasis on the Pr- and Sm-based ones. Until now, Pr-based ones, such as heavy Fermion superconductivity in PrOs4Sb12, metal-insulator transition in PrRu4P12 and field-induced heavy Fermion state above antiferro-quadrupolar ordered state in PrFe4P12, have been most intensively investigated. Quite a few attractive features have been found also in Ce- and Sm-based skutterudites; such as recently found novel heavy Fermion state robust against magnetic fields in SmOs4Sb12. We discuss the novelty and variety of such attractive features in correlation with the unique crystal structure of the filled skutterudite.

For the filled skutterudite compounds, high-pressure synthesis is thought to be a powerful technique, because it is possible to synthesize compounds that could not been grown by the flux method under ambient pressure and to improve the filling factor of rare-earth ions. In this article, we report the details of high-pressure synthesis of the filled skutterudite PrFe4Sb12 and the brief result of its physical properties. As a result, we have succeeded in synthesizing high-quality crystals of PrFe4Sb12 with higher Pr-filling factor and obtaining information about the crystalline electric field of PrFe4Sb12.

The magnetic torque measurements were performed on two MgB2 single crystals with the different values of upper critical fields Hc2 (3.7 T and 3.1 T at 4.2 K). At low temperatures, the irreversible torque-vs-field curves τ(H) in the both samples show the peak effect, accompanied by the field-history dependence, close to Hc2 for all the field directions measured. With increasing temperature, the peak in τ(H) becomes less pronounced, and disappears around T = 27 K. In the sample with smaller Hc2, τ(H) curves display diamagnetic steps at the higher temperatures. On the other hand, in the sample with larger Hc2, such a step is not observed. Our results suggest that the order–disorder transition around the peak transforms to the first-order melting transition, which is very sensitive to the degree of disorder.

Specific heat and transport measurements have revealed an unconventional heavy-fermion (HF) state in SmOs4Sb12 single crystals. The electronic specific-heat coefficient (gamma=0.82 J/K^2mol) and the coefficient (A) of the quadratic temperature dependence of electrical resistivity are largely enhanced, although the ratio A/gamma^2 is reduced from the Kadowaki-Woods ratio of HF materials. Both gamma and A do not show any significant decrease in applied field in contrast with Ce-based HF compounds, suggesting an unconventional origin of the heavy quasiparticles. A weak ferromagnetic ordering sets in below about 3 K, probably originating in the itinerant quasiparticles., Comment: 5 pages, 8 figures. To appear in J. Phys. Soc. Jpn., vol.74 (2005)

症例は53歳男性. 視力の低下を自覚し眼科受診, ぶどう膜炎を指摘された. サルコイドーシス精査の胸部レントゲンにて胸部異常陰影を指摘され当科に紹介となった. 胸部CTにてA-P windowに針状の金属片と思われる異物を認めた. 透視を併用した胸腔鏡下摘出術を試みたが異物の占拠部位の同定に難渋したため, 腋窩開胸へ術式を変更して摘出した. 異物は形状より縫い針と思われた. 本症例は外傷, 手術の既往, 及び, 精神疾患の既往はなく, 侵入経路が不明な縦隔内伏針と診断した. 文献上, 胸腔内伏針の経路は不明なものが半数以上を占めており, 臓器外 (心臓, 大動静脈, 肺動静脈, 気管, 食道以外) の縦隔内伏針は本症例を含めて2例のみであった.

We have grown high quality single crystals of MgB 2 by the encapsulation method. A new method which combines the magnetic torque method and the field modulation method is successfully employed to detect the dHvA oscillation and the AC response of the superconductor down to the fields below H c2 . The AC torque signal indicates that the surface superconductivity develops well above H c2 and it evolves into the bulk superconductivity with decreasing field. The irreversible torque curve is observed at much higher fields than H c2 and can be attributed to a pinning effect of the surface vortices. The superconducting transition detected by the AC torque method significantly broadens indicating that the supercondcuting fluctuation is not negligible. It is suggested that both the surface superconductivity and the fluctuation contribute considerably to the broadening of the resistive transition. We have found that the damping of the dHvA signal from the π band is very large around H c2 due to the superconducting fluctuation and the pinning effect, but the damping rate becomes moderate with further decreasing field, implying that the superconducting gap may be small for the π band near H c2 .

Field variation of the entropy S ( H ) of the spin ice compound Dy 2 Ti 2 O 7 has been examined by means of magnetocaloric effect measurements in a magnetic field H ∥[111], with attention focused o...

Two kinds of substituted systems, Yb 4 (As 1- x Se x ) 3 and Yb 4 (As 1- x Sb x ) 3 , were investigated to clarify the electronic structure of Yb 4 As 3 . By the comparison of the magnetic and transport properties of these systems, it is revealed that the Se-substitution causes the decrease of the Yb 3+ ions, while the Sb-substitution causes the increase of the holes and the decrease of the Yb 3+ ions simultaneously. These results indicate that the number of the holes on the valence p -band almost corresponds to the number of the Yb 2+ ions on the one-dimensional magnetic chains in Yb 4 As 3 . This scenario could explain many physical properties of the substituted and non-doped Yb 4 As 3 .

We have investigated transport properties of a cubic Kondo system, Ce0.5La0.5B6, with a ?8 ground state. The resistivity shows a non-Fermi liquid behaviour in phase I. In antiferromagnetic phase III, the resistivity follows well the formula ?(T) = ?(0) + AT2. The coefficient A for phase III is much larger than that of CeB6 in phase III. The magnetic phase diagram for H ? [110] has been obtained.

We report unambiguous microscopic evidence from 31 P NMR under \(H_{\text{ext}}\cong 7.3\) T for significant ionic disorder in the Yb 3+ chain in Yb 4 (As 1- x P x ) 3 ( x =0.05 and 0.40), which ha...

We report our recent developments of experimental systems for measuring the de Haas–van Alphen (dHvA) effect under hydrostatic and uniaxial pressures. The dHvA effect of CeB6 has been studied under both hydrostatic and uniaxial pressures and the effects of the pressures on the electronic structure are discussed.