ABSTRACT
Recent research studies show that acoustic emission (AE) technologies have great potential in detecting the flattened defects of wheel; however, the wheel-rail rolling interference (WRRI) significantly influences the accuracy of wheel defect detection. Aiming to solve the above-mentioned problem, a novel detection method, which combines an improved synthesized health index (ISHI) with a time adaptive threshold (time-ATH), is proposed in this article. In order to obtain the defect information from the signals generated by the wheels, a completed feature set that contains many types of features is extracted from AE signals. Then, the ISHI is fused by several effective features that are selected from the completed feature set, according to detection rate and accuracy. Besides, a time-ATH calculation is proposed to detect the defective signals of wheels and reduce the influence of the WRRI. The method is fully verified in actual datasets, and the results show that the proposed method achieves a better detection rate and accuracy. Moreover, it provides an effective way for the AE detection of wheel-flattened defects under strong and numerous WRRI.
Subject(s)
AcousticsABSTRACT
Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are mesenchymal tumors characterized by "staghorn" blood vessels and collagen deposition. Little is known about SFT/HPCs with papillary architecture. We summarized the clinicopathologic features of 12 patients with papillary SFT/HPCs (8 males and 4 females; median age: 59 years), including 8 previously reported cases. Tumors were present in the meninges (75%, 9/12), adrenal gland (8%, 1/12), orbit (8%, 1/12), or spinal canal (8%, 1/12). Six tumors (50%) had a true papillary architecture with fibrovascular cores and 6 tumors (50%) had a pseudopapillary architecture with vascular cores. Nuclear staining for STAT6 was present in all tested tumors (10/10). RT-PCR indicated NAB2 ex6-STAT6 ex17 fusion in 4 tumors (80%, 4/5) and NAB2 ex4-STAT6 ex2 fusion in 1 tumor (20%, 1/5). Five patients (42%, 5/12), all with tumors in the meninges, developed local recurrence at a median of 61 months after surgery (range: 56-165 months; mean: 88.6 months). These results indicated that the papillary architecture is a morphological form of SFT/HPCs. The recognition of this pattern, with appropriate immunohistochemical analysis and assessment of NAB2-STAT6 fusion, should facilitate the distinction of these rare neoplasms from morphologically similar tumors in the meninges, lung, pleura, and soft tissue.
ABSTRACT
BACKGROUND: There have been few neuroendocrinology studies of suicidal behaviors among patients with depression and the results of these studies have been inconsistent. AIM: To explore the association between the function of the hypothalamus-pituitary-adrenal (HPA) axis and suicidal behaviors in Chinese patients with depression. METHODS: Several measures of HPA functioning in 14 depressed patients who had had suicidal behaviors in the two prior months ('depressed cases') were compared to those of 15 depressed inpatients who did not have prior suicidal behaviors ('depressed controls'): a dexamethasone suppression test (DST), the diurnal changes in serum cortisol levels during a single day before and after 6 weeks of treatment with paroxetine; and 24 h urinary 17-OH cortisol and free corticosterone before and after treatment. The Hamilton Depression Scale (HAMD) was used to measure the severity of depression. Daytime cortisol levels were also assessed in 15 non-depressed controls selected from individuals who had a routine health exam. RESULTS: There were no statistically significant differences in the 24 h urinary measures of cortisol and corticosterone between depressed cases and depressed controls. In both groups the normal midnight drop in serum cortisol was nonsignificant prior to treatment but after treatment it became more pronounced. The DST was positive in more of the depressed cases than depressed controls (57% v. 20%, χ(2)=4.24, p=0.039). The correlation of cortisol serum levels with the HAMD total score and the item scores for hopelessness and suicidal ideation were statistically significant in the depressed case group both before and after treatment, but in the depressed control group these correlation coefficients did not reach statistical significance. The 08.00 h serum cortisol level in depressed cases was significantly greater than the level in non-depressed controls both before and after treatment, but the level in depressed controls was not significantly greater than that in non-depressed controls. CONCLUSION: These findings are broadly consistent with those of prior studies about the relationship of depression and the functioning of the HPA axis. There were, however, some differences between depressed patients that did and did not report prior suicidal behavior which may indicate suicide-specific characteristics of HPA axis dysfunction. These differences merit further assessment in larger studies that distinguish patients who have made suicide attempts from those who only report prior suicidal ideation.
