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This study proposed deep learning-based ultrasonic nondestructive testing for porosity evaluation of additively manufactured components. First, porosity mechanisms according to additive manufacturing (AM) processing conditions were studied using traditional scanning acoustic microscopy and optical microscopy. Second, correlations between ultrasonic properties and porosity content were analyzed. The correlation results showed that the increased porosity content resulted in a decreased ultrasonic velocity and increased ultrasonic attenuation coefficient. Third, various levels of porosities were evaluated using a deep learning model based on a fully connected deep neural network that was trained on raw ultrasonic signals measured in the AM samples. After training, the testing performance of the trained model was evaluated. Additionally, the generalization performance of the pre-trained model was assessed using newly fabricated AM samples that were not used for training. The results showed that the porosity content evaluated by the pre-trained model matched well with that measured via traditional scanning acoustic microscopy, thus demonstrating the feasibility of deep learning-based ultrasonic nondestructive testing for porosity evaluation of additively manufactured components.

This paper discusses the two-phase flow pattern and temperature distribution in a loop thermosyphon as a defrost device at the surface of the evaporator in the refrigerator with different heater locations and different heating power. A computational fluid dynamics (CFD) study was carried out using ANSYS FLUENT 15.0. The volume of fluid (VOF) model was considered to simulate evaporation and condensation at the heater surface using user-defined functions (UDFs). 2D geometries were developed with a heater inserted in the loop thermosyphon. The simulation results were verified using Fadhl’s experimental and numerical temperature data [2]. The maximum difference is 2.4 % between the calculated data and Fadhl’s data. The two-phase flow pattern and the temperature field varied with the different heater locations and heating power values. The thermal performance was evaluated based on the average temperature and temperature uniformity inside the loop thermosyphon.

Increased serum biomakers, such as S100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE), are associated with traumatic brain injury (TBI). The purpose of this study is to investigate the serum levels of S100B and NSE in pediatric TBI patients and to predict a clinical outcome. Peripheral venous blood was collected within 6 h of injury and at 1 week to measure S100B and NSE. The serum S100B and NSE levels were measured using commercially available enzyme-linked immunosorbent assay kits. The authors divided participants into two groups at admission: a favorable group (patients with Glasgow Coma Scale [GCS] scores of 10–15) and an unfavorable group (patients with GCS scores of less than 9). Both S100B and NSE levels were compared between the two groups at the time of admission and 1 week later. Ten pediatric patients were enrolled (5 in the favorable group, 5 in the unfavorable group). The median serum S100B level of 134.21 pg/ml (range, 51.00–789.65 pg/ml) in patients with TBI at admission dropped to 41.49 pg/ml (range, 25.65–260.93 pg/ml) after 1 week, with significant differences between the traumatic event and 1 week later (p = 0.007). The median serum NSE level of 14.76 ng/ml (range, 6.48–21.23 ng/ml) in patients with TBI at admission was higher than that after 1 week (4.96 ng/ml, range, 3.01–31.21 ng/ml), with significant differences (p = 0.015). A significant difference was observed in S100B after 1 week between patients in the favorable and unfavorable groups (p = 0.047). One patient whose serum S100B and NSE levels were elevated 1 week after TBI eventually died. Elevated serum S100B and NSE levels in pediatric TBI patients decreased 1 week after traumatic events. The serum S100B level 1 week after TBI was related to the severity of brain damage. These results indicated that serum S100B and NSE might play a role in predicting the prognosis and monitoring ongoing brain injury in pediatric TBI patients.

The relative acoustic nonlinearity parameter β' is defined by the amplitudes of the fundamental and second-order harmonic components in the detected ultrasonic wave signal, in which a piezoelectric transducer is conventionally used for detection. Although it is not identical to the absolute parameter β defined by the displacement amplitudes, β' has been widely used for the relative comparison between the same materials since its ratio is identical to that of the absolute parameter when the detected signal amplitude is proportional to the displacement amplitude. However, β cannot be replaced by β' for the comparison between different materials due to the difference of respective acoustic impedance. This study aims to show that a laser detection method using a photorefractive interferometer can be used for the relative comparison of acoustic nonlinearity between different materials because its output is independent of the acoustic impedance. To demonstrate, two similar materials, Al6061-T6 and Al2024-T4, and one different material, copper, were tested. Experimental results showed that the ratio β 2024 / β 6061 , measured via the proposed method and the conventional piezoelectric detection method, were in good agreement with the references. However, in the case of β Cu / β 6061 , only the proposed method showed good agreement with the references.

To assess the efficacy of stereotactic radiosurgery (SRS) for intracranial dural arteriovenous fistulas (DAVFs), the authors retrospectively reviewed our 7-year experience. We evaluated the obliteration rate, improvement in clinical symptoms, and complications. Thirty patients with DAVF underwent SRS using a Gamma Knife between 2009 and 2015. Twenty-three patients were treated with SRS alone, and seven patients underwent SRS for residual or recurrent DAVFs after embolization or surgery. Chemosis, diplopia, and pulsating tinnitus were the most common symptoms. Median target volume was 2.9 cm3 (range, 0.8–13.6 cm3), and median radiation dose to the target was 17 Gy (range, 12–20 Gy). Median follow-up period was 33 months (range, 6–82 months). At the last neuroimaging follow-up, DAVFs were totally obliterated in 23 patients (77%) and subtotally in 7 (23%). At the last clinical follow-up, 21 patients (70%) showed complete recovery, and 9 (30%) showed incomplete recovery in symptoms or signs. None experienced worsening symptoms or signs. Asymptomatic perilesional edema after SRS occurred in one patient (3%). Total obliteration rates after SRS were 43% at 1 year, 79% at 2 years, and 95% at 5 years. Improvement rates of neurological function after SRS were 12% at 1 month, 52% at 2 months, 72% at 3 months, and 96% at 6 months. A multivariate analysis revealed that Borden type 1 (p = 0.019, hazard ratio, 3.254, 95% confidence interval, 1.216–8.707) was significantly associated with symptom improvement. SRS for intracranial DAVFs provided a high obliteration rate and a relatively low risk of radiation-induced complications. In selected benign cases without cortical venous drainage, SRS is a safe and effective treatment for symptom relief and fistula obliteration, even though the time course of improvement is longer than those of embolization and surgery.

Perturbations in cellular chloride concentrations can affect cellular pH, autophagy and lead to the onset of apoptosis. With this in mind synthetic ion transporters have been used to disturb cellular ion homeostasis and thereby induce cell death; however, it is not clear whether synthetic ion transporters can also be used to disrupt autophagy. Here we show that squaramide-based ion transporters enhance the transport of chloride anions in liposomal models and promote sodium chloride influx into the cytosol. Liposomal and cellular transport activity of the squaramides is shown to correlate with cell death activity, which is attributed to caspase-dependent apoptosis. One ion transporter was also shown to cause additional changes in the lysosomal pH which leads to impairment of lysosomal enzyme activity and disruption of autophagic processes. This disruption is independent of the initiation of apoptosis by the ion transporter. This study provides the first experimental evidence that synthetic ion transporters can disrupt both autophagy and induce apoptosis.

The actin-binding protein fascin has been associated with clinically aggressive tumors and poor prognosis. The purpose of this study was to investigate possibility of fascin expression as a prognostic factor in a newly diagnosed primary glioblastoma (GBM). Between July 2007 and December 2013, 37 out of 126 patients diagnosed with GBM satisfied the following inclusion criteria: (1) the presence of immunohistochemically-available tissue, (2) a new primary GBM, (3) gross-total resection, and (4) standardized adjuvant treatment, known as the Stupp regimen. The median follow-up period was 18 months (range 5-95). According to the staining intensity of fascin, progression-free survival (PFS) in the low-intensity fascin group (median PFS 9.0 months; 95 % CI 6.0-12.0) was longer than PFS in the high-intensity fascin group (median PFS 7.0 months; 95 % CI 5.6-10.4; p = 0.024). Overall survival (OS) in the low-intensity fascin group (median OS 20.0 months; 95 % CI 17.7-22.4) was longer than OS in the high-intensity fascin group (median OS 13.0 months; 95 % CI 8.2-17.8; p = 0.031). And, the staining intensity of fascin was a statistically significant factor in PFS and OS according to univariate and multivariate analyses (univariate analysis p = 0.043 and p = 0.043; multivariate analysis p = 0.041 and p = 0.044). Our clinical study showed that fascin expression intensity may be correlated with clinical outcomes of a newly diagnosed primary GBM, especially with regard to PFS and OS.

We investigated the flow and heat transfer characteristics in a Twisted elliptic tube (TET). The effects of geometry parameters such as the aspect ratio and number of rotations in the TET were analyzed comparatively using three-dimensional (3-D) numerical simulation. We also solved numerically the conservation equations of continuity, momentum, and energy in the TET. Fully developed flow in the TET was modeled using the realizable k-e turbulence model and steady incompressible Reynolds-averaged Navier-Stokes (RANS) equations. The simulation was performed for Reynolds numbers of 100, 1000 and 10000. The pressure drop and the heat transfer of the TET were assessed in terms of the Darcy friction factor and Colburn j-factor, and overall performance was evaluated using the area and volume goodness factors.

In order to evaluate long term clinical and imaging outcomes, the authors retrospectively reviewed our 22-year experience using stereotactic radiosurgery (SRS) for tentorial meningiomas. Thirty-nine patients with tentorial meningiomas underwent SRS using various Gamma Knife technologies between 1988 and 2010. The most common presenting symptoms were headache, dizziness or disequilibrium, and ataxia. The median tumor volume was 4.6 cm(3) (range 0.5-36.6 cm(3)) and the median radiation dose to the tumor margin was 14 Gy (range 8.9-18 Gy). The median follow-up period was 41 months (range 6-183 months). At the last imaging follow-up, tumor volumes decreased in 22 patients (57 %), remained stable in 13 patients (33 %), and increased in 4 patients (10 %). The progression-free survival after SRS was 97 % at 1 year, and 92 % at 5 years. At the last clinical follow-up, 35 patients (90 %) showed no change in symptoms, 1 patient (2 %) showed improvement of their neurologic symptom, and 3 patients (8 %) demonstrated worsening symptoms. The rate of symptom worsening after SRS was 5 % at 1 year, and 10 % at 5 years. Asymptomatic peritumoral edema after SRS occurred in 2 patients (5 %). Symptomatic adverse radiation effect developed in 2 patients (5 %). SRS for tentorial meningiomas provided long-term effective tumor control and a low risk of radiation related complications.

Pituitary carcinomas, which are rare, generally present with craniospinal and systemic metastases. Although several treatments exist, the prognoses of patients with pituitary carcinomas are extremely poor to date. In this report, the authors describe the case of a 23-year-old male who had undergone trans-sphenoidal surgery and radiotherapy for an invasive prolactinoma. Seven years later, he presented with a new 4th ventricle metastasis from the pituitary lesion, and it was diagnosed with a pituitary carcinoma. He underwent resection and Gamma-knife radiosurgery (GKRS). The tumor has been well controlled for over 3 years. To our knowledge, there have been no reports of the effects of GKRS in patients with pituitary carcinomas. GKRS might have considerable effects in the treatment of pituitary carcinomas.

The pathogenesis of chronic subdural hematoma (CSDH) associated with an arachnoid cyst (AC) is still not clear. We propose an origin of initial bleeding of CSDH in patients with AC based on our experience and discuss the management of this disease. The total number of operations included in this study was 23. Eleven cases were indicated because of associated CSDH (group 1), and the other cases were due to different reasons (group 2). The relationship of the AC and dura was evaluated in patients who did not have CSDH (group 2) because patients with CSDH would have had structural changes of AC due to hematoma. In group 1, the age distribution was from 8 to 61 years (mean 23.0). The development of CSDH was not related with Galassi types. The hematomas were located outside of the outer cyst membrane in six patients and both inside and outside in three patients. In two patients, the location could not be reviewed. After suspicion of the outer cyst membrane as the origin of the bleeding site, we found small bridging vessels between the dura and outer cyst membrane in three of five consecutive patients in group 2. Based on our surgical experience of AC cyst, we found small bridging vessels between the dura and outer membrane of the AC. We suggested that these small vessels are the source of initial bleeding leading to CSDH in AC.

The present study investigated the incidence of acute rebleeding after successful coil embolization of a ruptured cerebral aneurysm, including clinical outcomes, and possible mechanisms of the events other than coil compaction and/or incomplete embolization. This study included 591 consecutive patients who presented with aneurysmal subarachnoid hemorrhage, were treated with coil embolization, and whose post-procedural angiography revealed successful embolization. Data were collected retrospectively from six patients who showed acute rebleeding despite that angiographically successful coil embolization was achieved. All clinical, radiological data and intraoperative videos were reviewed to identify causative factors which could have contributed to the occurrence of rebleeding. Incidence of acute rebleeding after successful coil embolization of ruptured cerebral aneurysm was 1.0% (6/591). In all of these six patients, complete angiographic occlusion was achieved except in one case where a small residual neck was intentionally left to avoid compromise of the parent artery. Four of the six patients showed poor clinical courses, either died or recovered with severe disability. Whenever possible, we performed an immediate craniotomy for exploration and additional clipping. Based on intraoperative findings, we hypothesized that uneven distribution of the coil masses and spontaneous resolution of thrombus among the strands of coil (inter-coil-loop thrombolysis) could be possible mechanisms of rebleeding. Acute rebleeding is extremely rare, but is possible as a complication of coil embolization of a ruptured cerebral aneurysm even when a case is angiographically successful. The higher degree of morbidity and mortality is a major concern. Therefore, further investigation to discover risk factors and causative mechanisms for such a complication is sorely needed.