Internal Motion of 6.7-GHz Methanol Masers in H II Region S269

We present the first internal motion measurement of the 6.7-GHz methanol maser within S269, a small HII region in the outer Galaxy, which was carried out in 2006 and 2011 using the Japanese VLBI Network (JVN). Several maser groups and weak isolated spots were detected in an area spanning by ~200 mas (1000 AU). Three remarkable maser groups are aligned at a position angle of 80 degree. Two of three maser groups were also detected by a previous observation in 1998, which allowed us to study a long-term position variation of maser spots from 1998 to 2011. The angular separation between the two groups increased ~10 mas, which corresponds to an expansion velocity of ~10 km s^{-1}. Some velocity gradient (~10^{-2} km s^{-1} mas^{-1}) in the overall distribution was found. The internal motion between the maser groups support the hypothesis that the methanol masers in S269 could trace a bipolar outflow.Comment: 8 pages, 6 figures, accepted for publication in PAS

On Generalizations of Anabelian Group-theoretic Properties

In the present paper, we discuss certain generalizations on two anabelian group-theoretic properties --strong internal indecomposability and elasticity. More concretely, by replacing the normality conditions appearing in characterizations of strong internal indecomposability and elasticity by the subnormality conditions, we introduce the notions of strong sn-internal indecomposability and sn-elasticity and prove that various profinite groups appearing in anabelian geometry satisfy these properties

The Anabelian Geometry of Configuration Spaces of Hyperbolic Curves in Positive Characteristic

In the present paper, we prove the anabelian Grothendieck conjecture for the tame fundamental groups of the configuration spaces associated to hyperbolic curves over [the perfections of] finitely generated fields of positive characteristic. The main theorem of the present paper generalizes the classical anabelian results for hyperbolic curves in positive characteristic established by A. Tamagawa, S. Mochizuki, and J. Stix. The main theorem of the present paper may also be regarded as the first anabelian Grothendieck conjecture-type result for algebraic varieties in positive characteristic of higher dimension [i.e., of dimension greater than one]. In the process of the proof of the main theorem, we prove a certain exactness of homotopy sequences for the tame fundamental groups with respect to suitable morphisms between normal varieties. Moreover, we also introduce the notion of a generalized fiber subgroup of the tame fundamental group of the configuration space associated to a hyperbolic curve in arbitrary characteristic and establish a “group-theoretic algorithm” that reconstructs, from the tame fundamental group of the configuration space, the generalized fiber subgroups

VERA monitoring of the radio jet 3C 84 during 2007--2013: detection of non-linear motion

We present a kinematic study of the subparsec-scale radio jet of the radio galaxy 3C 84/NGC 1275 with the VLBI Exploration of Radio Astrometry (VERA) array at 22 GHz for 80 epochs from 2007 October to 2013 December. The averaged radial velocity of the bright component "C3" with reference to the radio core is found to be $0.27 pm 0.02c$ between 2007 October and 2013 December. This constant velocity of C3 is naturally explained by the advancing motion of the head of the mini-radio lobe. We also find a non-linear component in the motion of C3 with respect to the radio core. We briefly discuss possible origins of this non-linear motion.Comment: 11 pages, 7 figures, 8 tables (table 1 - 5 are supplementaries), accepted for publication on PAS

Imaging tools for mediastinal cystic lesions

Objective : To identify and differentiate patients with mediastinal cysts from those with cystic tumors requiring surgery. Methods : A total of 36 patients with mediastinal cystic lesions were enrolled. The patients were separated into two groups based on pathological findings : those with mediastinal cysts (n=23) and those with mediastinal tumors (n=13). The cystic components were measured using imaging parameters including mean computed tomography (CT) value, apparent diffusion coefficient (ADC), T1 signal intensity ratio (T1SI-ratio), and T2 signal intensity ratio (T2SI-ratio), acquired from magnetic resonance imaging (MRI) ; and standardized maximum uptake value (SUVmax) from 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Both groups were statistically compared. Results : Comparative parameters between the cysts and tumors revealed the following ratios : CT value, 40.9±21.2 versus (vs) 24.8±12.9 (p = 0.019) ; SUVmax, 1.18±0.50 vs 4.32±3.52 (p = 0.003) ; ADC, 3.46±0.96 vs 2.68±0.74 (p = 0.022) ; T1SI-ratio, 1.06±0.60 vs 1.35±0.92 (p = 0.648) ; T2SI-ratio, 5.40±1.80 vs 4.33±1.58 (p = 0.194). However, there was no correlation between FDG uptake and ADC value. Conclusions : SUVmax from 18F-FDG PET/CT and ADC derived from MRI were effective in facilitating preoperative diagnosis to differentiate mediastinal cysts from tumors. However, these examinations may be complementary to one another, not dominant

甲状腺癌リンパ節転移との鑑別が困難であった頸部神経鞘腫の１例

A female patient in her 60s visited her previous doctor because of a right cervical mass that exist for 7 years and gradually increased in size. As she was suspected of cervical lymph node metastasis of thyroid cancer, she was referred to our hospital. At the initial visit, a 5-cm right cervical mass and enlargement of the right lobe of the thyroid gland were observed. Fine needle aspiration cytology was performed on both, but no malignant findings were observed. To confirm the diagnosis and improve the patient’s appearance, a right lobectomy of the thyroid gland and resection of the right cervical mass were performed. A rapid intraoperative histological examination of the cervical mass revealed a schwannoma. The right thyroid tumor was diagnosed as follicular adenoma. Her postoperative course was good, and after several years of follow-up, patient consultation was terminated. Neurolemmoma is a benign tumor arising from Schwann cells in the nerve sheath, and it occurs frequently throughout the head and neck region, with 25%-45% of cases occurring in this region. Cervical schwannomas are characterized by irritation of the vagus nerve, brachial plexus, and sympathetic nerves. However, many patients present with only a painless neck mass, as in this case. Although the mass can be diagnosed by puncture aspiration cytology in some cases, sufficient specimens are often unavailable, and the diagnosis is made preoperatively in about half of all cases. Differential diagnoses of an anterior cervical mass include malignant lymphoma, cervical lymph node metastases of malignant tumors, submandibular gland tumors, and tuberculous lymph node metastases. In this patient, we also considered lymph node metastasis of thyroid cancer. However, a histological examination did not detect malignancy in either the thyroid gland or neck mass, and we considered that the thyroid follicular adenoma and the cervical schwannoma occurred independently. We report our experience of cervical schwannoma combined with thyroid tumor which was suspected of lymph node metastasis of thyroid cancer

AYA-generation lung cancer in a patient presenting with spontaneous pneumothorax : A case report

Background : Surgery for young patients（i.e., <２０ years of age）with early-stage lung cancer is extremely rare. To the best of our knowledge, only a few cases of lung cancer initially presented with spontaneous pneumothorax. Here, we report a case of AYA（adolescent and young adult）-generation lung cancer in a patient who presented with spontaneous pneumothorax. Case : An １８-year-old male was admitted to our hospital for new-onset left pneumothorax. Chest computed tomography incidentally revealed a pure ground-glass nodule（pGGN）in the left lower lobe（S８）with a bulla near the nodule. While chest tube drainage improved his condition, pneumothorax recurred two weeks later, prompting surgical for video-assisted partial resection of the left lung. Intraoperative findings showed that the bulla and nodule were distant. Histopathologic analysis was consistent with a diagnosis of adenocarcinoma in situ with a bleb. Conclusion : This study highlights the importance of considering the possibility of lung cancer in patients with irregular chest shadows, even those less than２０years of age. Computed tomography plays an important role in the diagnosis of lung cancer in patients with spontaneous pneumothorax

中毒性多結節性甲状腺腫

A woman in her 80s who was diagnosed with multiple thyroid tumors and subclinical hyperthyroidism 1 year previously was referred to our outpatient clinic due to deteriorated hyperthyroidism. She was diagnosed with dilated cardiomyopathy 4 years ago. Her cardiac function has been stabilized with medical conservative treatment. Blood autoantibody levels, including TSAb and TRAb, were within normal ranges. Ultrasonography and computed tomography revealed multiple tumor lesions in both thyroid lobes. Tc-99m scintigraphy showed multiple hot nodules in both thyroid lobes. Because the patient’s thyroid function had deteriorated, we selected surgical total thyroidectomy rather than radioisotope treatment as the most appropriate treatment. Histopathological examination of the resected specimen demonstrated multiple nodular lesions with a maximum size of 23 mm and a microlesion of papillary carcinoma 2 mm in diameter in the thyroid. A few days after surgery, thyroid function blood levels declined to the normal range