216 research outputs found
Compressor with Turning-Paired Vane and Piston
With the aim of energy saving of room air conditioners, we are addressing higher efficiency of the rotary compressor that is used most in the world. We focused on a new rotary compressor equipped with a mechanism to restrict the rolling motion of the piston, and performed the dynamics analysis. The new rotary compressor has a small pillar at the tip of the vane and constitutes a turning pair of vane and piston, and it limits the rolling motion of the piston. By means of limiting the piston rotation, the heat transfer to the suction process from the compression chamber will be suppressed, and we can expect higher compression efficiency. Before examining the compression efficiency, we performed the dynamics analysis of this new rotary compressor and examined the forces and dynamic behavior of the components, and the mechanical efficiency of the compressor. Then we have following results. (1)We can clarify the contact point between the vane tip and piston in the turning pair by considering the equilibrium of forces and moments acting on the vane. (2)By reducing the diameter of the pillar at the vane tip, the vane tip friction loss is reduced, and the mechanical efficiency is improved. (3)The new rotary compressor has less vane tip friction loss and on the other hand greater friction loss between the vane side and the cylinder in comparison to the rolling piston rotary compressors. As a result, both compressors have almost the same mechanical efficiency
Clinical Usefulness of Contrast-Enhanced Three-Dimensional Ultrasound Imaging with Sonazoid for Hepatic Tumor Lesions
CLINICOPATHOLOGICAL STUDY OF CEREBRAL SUBCORTICAL CAVERNOUS ANGIOMA AS EPILEPTOGENIC FOCUS
The authors conducted a comparative histological study of two groups of patients with cerebral subcortical cavernous angioma. One group was composed of 5 asymptomatic cases detected accidentally. The other group was composed of 4 patients presenting as epilepsy. The results obtained may be summarized as follows ; 1) Hemosiderin deposit and gliosis were seen in all cases examined ; 2) Granulomatous change was a histological finding associated with epileptogenesis ; 3) The histological changes, starting with proliferation of collagen fibers and leading to hyaline degeneration, calcification, and then hemangioma calcificans, seem to represent a course of spontaneous healing, when viewed from epileptogenesis
Fluorescence-guided bone resection by using Visually Enhanced Lesion Scope in diffuse chronic sclerosingosteomyelitis of the mandible: clinical and pathological evaluation
Diffuse chronic sclerosingosteomyelitis (DCSO) is a refractory disease, becausethe etiology and pathogenesis remain poorly understood and to determine the border betweenunhealthy boneandhealthybone is difficult. However,
progressive inflammation, clinical symptoms and a high recurrence rate of DCSO were the reasons for surgical
treatment. We report a case of a 66-year old woman with DCSO of the right side of mandible who was treated with
hemimandibulectomy and simultaneous reconstruction by vascularized free fibula flap. After preoperative administration of minocycline for 1 month, the bone fluorescence was successfully monitored by using a Visually Enhanced Lesion Scope (VELscope®). Intraoperatively, we could determine the resection boundaries. We investigated
the clinical and histopathological findings. The fluorescence findings were well correlated with histopathological
findings. Using a VELscope®was handy and useful to determine the border between DCSO lesion andhealthybone.
The free fibula flap under the minocycline-derived bone fluorescence by using a VELscope®offered a good quality
of mandibular bone and the successful management of an advanced and refractory DCSO
Prognostic Impact of Pre- and Post-operative P-CRP Levels in Pancreatic Cancer Patients
Background: C-reactive protein (CRP) levels reflect ongoing inflammation and/or tissue damage, and studies suggest that platelets play a role in tumor invasion and metastasis. P-CRP is defined as the multiplied product of serum CRP and platelet levels. Here the prognostic value of pre- and post-operative P-CRP levels in pancreatic cancer (PC) patients was assessed. Methods: This retrospective study used data from 107 consecutive PC patients who had undergone either pancreaticoduodenectomy or distal pancreatectomy. Clinicopathological parameters and pre/post-operative laboratory data derived from patient records were used for analyses. P-CRP was defined as the product of peripheral thrombocyte count (/uL) × serum CRP level (mg/dL) divided by 104; the optimal P-CRP cut-off value was defined using receiver operating characteristic curves. Results: PC patients were classified as either P-CRPLow (< 1.782; n = 49) or P-CRPHigh (≥ 1.782; n = 58), based on the cut-off value of 1.782. Univariate analysis revealed that performance status, clinical stage, pathological T and N stages, P-CRP, and carbohydrate antigen 19-9 (CA19-9) significantly affected overall survival (OS). Multivariate analysis revealed that independent risk factors for OS were pathological N stage, P-CRP, and CA19-9. Additionally, 103 PC patients for whom postoperative data were available were classified into four groups (P-CRPLow-Down, P-CRPLow-Up, P-CRPHigh-Down and P-CRPHigh-Up), based on preoperative P-CRP and postoperative trend of P-CRP, and we found that prognosis, in terms of OS, was significantly different among these groups (P = 0.012). Conclusion: Pre- and post-operative P-CRP values are a potential predictor of prognosis in PC patients
骨髄間葉系細胞シートはラット脊髄離断損傷後にグリア瘢痕形成を抑制し、軸索再生と後肢運動機能改善を促進する。
OBJECTIVE Transplantation of bone marrow stromal cells (BMSCs) is a theoretical potential as a therapeutic strategy in the treatment of spinal cord injury (SCI). Although a scaffold is sometimes used for retaining transplanted cells in damaged tissue, it is also known to induce redundant immunoreactions during the degradation processes. In this study, the authors prepared cell sheets made of BMSCs, which are transplantable without a scaffold, and investigated their effects on axonal regeneration, glial scar formation, and functional recovery in a completely transected SCI model in rats. METHODS BMSC sheets were prepared from the bone marrow of female Fischer 344 rats using ascorbic acid and were cryopreserved until the day of transplantation. A gelatin sponge (GS), as a control, or BMSC sheet was transplanted into a 2-mm-sized defect of the spinal cord at the T-8 level. Axonal regeneration and glial scar formation were assessed 2 and 8 weeks after transplantation by immunohistochemical analyses using anti-Tuj1 and glial fibrillary acidic protein (GFAP) antibodies, respectively. Locomotor function was evaluated using the Basso, Beattie, and Bresnahan scale. RESULTS The BMSC sheets promoted axonal regeneration at 2 weeks after transplantation, but there was no significant difference in the number of Tuj1-positive axons between the sheet- and GS-transplanted groups. At 8 weeks after transplantation, Tuj1-positive axons elongated across the sheet, and their numbers were significantly greater in the sheet group than in the GS group. The areas of GFAP-positive glial scars in the sheet group were significantly reduced compared with those of the GS group at both time points. Finally, hindlimb locomotor function was ameliorated in the sheet group at 4 and 8 weeks after transplantation. CONCLUSIONS The results of the present study indicate that an ascorbic acid-induced BMSC sheet is effective in the treatment of SCI and enables autologous transplantation without requiring a scaffold.博士(医学)・甲第656号・平成28年11月24日© Copyright 2016 American Association of Neurological SurgeonsThe definitive version is available at " http://dx.doi.org/10.3171/2016.8.SPINE16250
Clinical Significance of Serum Antithrombin III Activity After Hepatectomy for Hepatocellular Carcinoma
[Background] As antithrombin III (AT-III) is produced in the hepatocytes, its serum activity decreases at the time of liver failure, in addition to ischemia reperfusion injury, vascular endothelial dysfunction, and disseminated intravascular coagulation (DIC). Here, we examined whether the serum AT-III value after hepatectomy could be a prognostic factor for hepatocellular carcinoma (HCC). [Methods] Of 141 patients who underwent hepatectomy for HCC, data for 101 patients in whom serum AT-III activity was measured on the first postoperative day were extracted. Patients with serum AT-III activity > 50% and ? 50% were assigned to high value (72 cases) and low value (29 cases) groups, respectively. We examined the clinical and prognostic differences between these two groups. [Results] The average age of enrolled patients (83 men and 18 women) was 68.0 years. The 5-year overall survival rate was 88% and 60% in the high and low value groups, respectively (P < 0.01). Furthermore, the 2-year relapse-free survival rate was 71% and 54% in the high and low value groups, respectively (P = 0.03). [Conclusion] This is the first study to demonstrate that serum AT-III levels on the first postoperative day may serve as a prognostic factor in HCC patients
近赤外線スペクトロスコピィを用いた覚醒剤精神病と統合失調症の鑑別
Despite some slight differences in symptomatology, differential diagnosis of methamphetamine-induced psychosis (MAP) versus schizophrenia can be challenging because both disorders present a large overlap in their clinical symptoms. However, a recent study has shown that near-infrared spectroscopy (NIRS) performed during a cognitive task can be a powerful tool to differentiate between these two disorders. Here, we evaluated verbal fluency task performance during NIRS in 15 patients diagnosed with MAP and 19 with schizophrenia matched for age and sex. We used prefrontal probes and a 24-channel NIRS machine to measure the relative concentrations of oxyhaemoglobin every 0.1 s during the task. For each patient, the neurocognitive function and clinical psychopathology were evaluated using the Positive and Negative Symptom Scale (PANSS), and the Brief Assessment of Cognition in Schizophrenia (BACS). Oxyhaemoglobin changes in the prefrontal cortex were significantly higher in the MAP group compared to those in the schizophrenia group, particularly in the right dorsolateral prefrontal cortex. In contrast, we found no significant difference in PANSS and BACS scores. Our findings suggest that NIRS measurement could be applied to differentiate patients with MAP from those with schizophrenia, even in cases where clinical symptoms are similar.博士(医学)・甲第645号・平成28年3月15日This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0
Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers
Background:
18
F-fluoro-2-deoxy-D-glucose (
18
F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads
to radiologists having difficulty in diagnosing the lesions. To examine the alterations in
18
F-FDG accumulation in
neck-related muscles of patients after ND for oral cancer.
Material and Methods:
18
F-FDG accumulations on positron emission tomography (PET)-computed tomography
(CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in
oral cancers.
Results: According to the extent of ND of cervical lymph nodes, the rate of patients with
18
F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical
sides. In addition, SUVmax of
18
F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were
increased according to the extent of the ND.
Conclusions: In evaluating
18
F-FDG accumulations after ND for oral cancers, we should pay attention to the
18
F-FDG
distributions in neck-related muscles including the non-surgical side as false-positive finding
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