Unveil Sleep Spindles with Concentration of Frequency and Time

Objective: Sleep spindles contain crucial brain dynamics information. We introduce the novel non-linear time-frequency analysis tool 'Concentration of Frequency and Time' (ConceFT) to create an interpretable automated algorithm for sleep spindle annotation in EEG data and to measure spindle instantaneous frequencies (IFs). Methods: ConceFT effectively reduces stochastic EEG influence, enhancing spindle visibility in the time-frequency representation. Our automated spindle detection algorithm, ConceFT-Spindle (ConceFT-S), is compared to A7 (non-deep learning) and SUMO (deep learning) using Dream and MASS benchmark databases. We also quantify spindle IF dynamics. Results: ConceFT-S achieves F1 scores of 0.749 in Dream and 0.786 in MASS, which is equivalent to or surpass A7 and SUMO with statistical significance. We reveal that spindle IF is generally nonlinear. Conclusion: ConceFT offers an accurate, interpretable EEG-based sleep spindle detection algorithm and enables spindle IF quantification.Comment: 22 pages, 6 figures, and 1 tabl

A Feasibility Study of Postoperative Adjuvant Therapy of Carboplatin and Weekly Paclitaxel for Completely Resected Non-small Cell Lung Cancer

IntroductionRecent clinical trials have shown significant survival benefits from postoperative adjuvant therapy for respectable nonsmall cell lung cancer (NSCLC). However, evaluation of adjuvant chemotherapy with carboplatin combination is still uncertain. The purpose of the study was to test the feasibility of adjuvant chemotherapy with carboplatin and separate weekly paclitaxel after complete resection of pStage IB, II, IIIA NSCLC in a multicenter study.MethodsThe study was conducted from 2001 to 2006 in the outpatient setting. A total of 61 patients were enrolled. Patients received adjuvant chemotherapy with 4 cycles of carboplatin (AUC 5) on day 1 and paclitaxel (70 mg/m2) on day 1, 8, and 15 every 4 weeks. Primary endpoints were toxicity and chemotherapy compliance. Secondary endpoints were disease-free survival and overall survival.ResultsMore than 65% of eligible patients had pStage IIIA. The median number of chemotherapy cycles was 4 (range 1–4). Grade 3 or 4 toxicities of neutropenia were 34% (grade 4: 2%). Other hematologic adverse effects were extremely less frequent. Regarding the nonhematologic adverse effect, hair loss was frequent; however, peripheral neuralgia was less frequent. Treatment-related death was not registered. During median follow-up of 21 months, 24 patients developed recurrent disease. Estimated disease-free survival and overall survival at 2 years was 51.2% and 84.6%, respectively.ConclusionsPostoperative carboplatin and weekly paclitaxel showed favorable feasibility and acceptable toxicity in comparison with the cisplatin-containing regimen. Consequently, it is desirable that this regimen would be validated in a phase III clinical trial for NSCLC after curative resection

Clinical significance of vascular endothelial growth factor and Delta-like ligand 4 in small pulmonary adenocarcinoma

Vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis. The notch ligand Delta-like ligand 4 (DLL4) is induced by VEGF and acts as a negative regulator of tumor angiogenesis by reducing the numbers of non-productive sprouting vessels. Several reports have shown the prognostic role of VEGF expression in non-small cell lung cancer. However, the correlation between VEGF and DLL4 expression and their clinical significance in non-small cell lung cancer remains unclear. The aim of this study was to analyze the correlation between the expression of VEGF/DLL4 and the clinicopathological background. Fifty-eight patients with lung adenocarcinomas measuring less than 3 cm in diameter who underwent surgical resection at Kawasaki Medical School Hospital from 2008 to 2010 were enrolled in this study. The expressions of VEGF, DLL4, CD31, and Ki-67 were analyzed using immunohistochemical staining. The tumor cells were VEGF-positive in 44 patients (75.9%) and DLL4-positive in 41 patients (70.7%). No statistically significant association was observed between the patients\u27 characteristics and VEGF/DLL4 expression. A high VEGF expression level tended to be associated with a high DLL4 expression level (P = 0.050, r = 0.258). The mean Ki-67 index was significantly lower in the patients with high VEGF expression (9.5 vs. 18.2, P = 0.011), but no significant difference was observed when patients were compared according to their DLL4 expression levels (11.8 vs. 11.0, P = 0.804). The mean Ki-67 index was higher in the VEGF_ DLL4_ patients than in the VEGFhigh DLL4high patients by a marginally significant difference (20.1 vs. 10.9 P = 0.056). The 3-year recurrence-free survival rates of the VEGF_/DLL4_ and the VEGF_/DLL4_ patients were 83.3% and 35.7%, respectively. The prognosis of the VEGF_/DLL4_ patients was significantly better than that of the VEGF_/DLL4_ patients (P = 0.032). To investigate the significance of the difference in tumor proliferation and prognosis between the VEGF_/DLL4_ and the VEGF_/DLL4_ patients, we evaluated the morphologic effect of VEGF/DLL4 expression on the intratumoral capillaries by counting the number of capillaries and calculating the luminal area (μm^2). No significant differences were seen between either the VEGF or DLL4 expression levels and the mean number of intratumoral capillaries or the luminal area (μm^2). In conclusion, VEGF_/DLL4_ patients with small pulmonary adenocarcinoma had a significantly poorer prognosis, although no significant difference in a morphological evaluation of the capillaries was seen between VEGF_/DLL4_ and VEGF_/DLL4_ patients

Three-Body Abrasive Wear-Resistance Characteristics of a 27Cr-Based 3V-3Mo-3W-3Co Multicomponent White Cast Iron with Different Ti Additions

A multicomponent white cast iron containing 5 wt.% each of Cr, V, Mo, W, and Co (MWCI) is known to have excellent wear-resistance properties due to the precipitation of some very hard carbides, such as MC, M2C, and M7C3. However, it seems possible to improve the wear resistance of MWCI by increasing the carbide volume fraction (CVF). Thus, 27 wt.% Cr based on 3 wt.% each of V, W, Mo, and Co was simultaneously added into the white cast iron. To avoid the tendency of carbides to crack due to high M7C3 precipitation levels, titanium (0–2 wt.% Ti) was also added. A rubber wheel abrasive machine test according to the ASTM G65 standard with two different abrasive particle sizes (average: 75 and 300 μm) was used to evaluate the wear characteristics of the alloy. The results show that the wear resistance of these new alloys (0Ti, 1Ti, and 2Ti) is lower than that of MWCI in small silica sand, owing to the lower hardness. However, a different condition is present in large silica sand, for which the abrasive wear resistance of MWCI is lower than that of the 0Ti and 1Ti specimens. In addition, TiC precipitation effectively refined the size of M7C3 carbides and reduced their cracking tendency. Thus, the wear resistance of 1Ti is comparable to that of 0Ti, although it has a lower hardness factor. However, the wear resistance of the alloy significantly decreased following the addition of Ti by more than 1 wt.% due to the lower hardness and CVF. Therefore, it can be said that the abrasive wear characteristics of the alloy are not only affected by the hardness, but also by the micro-structural constituents (type, size, and volume fraction of carbides) and silica sand size

Erosive Wear Behavior of Novel Hybrid Multicomponent Cast Alloys with Different C and B Contents

Multicomponent and high-boron cast alloys have been recognized as materials with excellent wear resistance due to the formation of hard phases called carbides and borides. However, the wear performance of the combination of these two materials called hybrid multicomponent cast alloys (HMCAs) has not been comprehensively studied. Therefore, this study will evaluate the effect of C (0–0.9 wt.%) and B (1.5–3.5 wt.%) addition on the erosion wear behavior of an HMCA containing 2.5 wt.% Ti, 10 wt.% Cr, and 5 wt.% each of V, Mo, and W. Shot-blast erosion testing was used to evaluate the wear resistance of each alloy. The test was conducted for 3600 s using 2 kg of irregularly shaped steel sand as a scraper at impact angles of 30°, 60°, and 90°. The results showed that the highest wear rate in 0C and 0.45C with 1.5–3.5% B occurred at an impact angle of 60° due to gouging and indentation mechanisms occurring simultaneously. However, different results occurred in the case of 0.9C with the same amount of B where the wear rate increased with increasing impact angle due to brittleness. Based on the chemical composition, the wear resistance of the alloy increased with increasing C content due to higher hardness values. However, the reverse performance occurred when the addition of B exceeded the threshold (more than 1.5 wt.%) despite the higher hardness. This fact was due to the susceptibility to carbide cracking as the amount of B increased. Therefore, the alloy with the best erosion wear resistance was 0.9C–1.5B HMCA

Three-Body Abrasive Wear Performance of High Chromium White Cast Iron with Different Ti and C Content

The need for better wear-resistant materials to reduce cost and save the environment is noteworthy. The striking wear resistance of high chromium white cast iron (HCCI) has made it industry’s predominant choice. The three-body abrasive wear resistance performance of HCCI was investigated based on combined Ti and C. The Ti and C content varied in different percentages. The addition of Ti resulted in refined M7C3 carbides and TiC crystallization. The hardness was significantly affected by the addition of Ti. The increment in Ti content resulted in a decrease in the hardness, leading to a higher wear rate. However, the individual contribution of C led to higher hardness and, hence, better wear resistance, which is contrary to Ti. Out of the three specimens with 3, 3.5, and 4 wt.% C content, the 4 wt.% C series showed the highest hardness but the lowest wear rate and depth. This study found that the combination of a lower percentage of Ti with a higher percentage of C in HCCI can have a worthwhile result in abrasive wear

Effect of Carbon Content on Three-body Abrasive Wear Characteristics of 28Cr-3Ni Cast Alloys

Abrasive wear resistance of white cast iron can be improved by adding transition metals due to carbide formation and matrix stabilization. However, it must also be affected by carbon content which has received little attention from researchers. Therefore, this study would investigate the influence of (1.4 and 2.8 wt.%) C on three body abrasive wear characteristics of 28Cr-3Ni cast alloys. High Cr-based multi-component white cast irons (Hi-Cr MWCIs) were used as comparison materials to estimate the life-service of each material. The abrasion test was performed using a rubber wheel abrasion machine test with two different sizes of silica sands (1100HV1). As results, the microstructure consists of martensite (the main matrix) and M7C3 carbide. Additionally, M2C carbide was also precipitated on the microstructure of Hi-Cr MWCIs. Meanwhile, Ni or Co was embedded in the matrix area of materials microstructure. In the case of 28Cr-3Ni, the higher amount of C has a higher carbide volume fraction and hardness leading to be better abrasive wear resistance at high loads. However, the reverse trend occurred at low loads with different sizes of abrasive particles. By comparing to Hi-Cr MWCIs, its abrasive wear resistance is lower owing to the fewer carbide types. In the case of Hi-Cr MWCIs, the higher Cr addition significantly consumes C content during the solidification process resulting to lower hardness and wear resistance. Therefore, it can be concluded that the three abrasive wear performance of materials is strongly influenced by C content, applied load, and abrasive particle size

A Study of the Three-Body Abrasive Wear Resistance of 5V/5Nb-5Cr-5Mo-5W-5Co-Fe Multicomponent Cast Alloys with Different Carbon Percentages

Since it is well known in the literature that transition metals can form extremely hard carbides and effectively strengthen a material’s matrix, recently, some of them, such as V, Nb, Cr, Mo, and W, have been simultaneously added to cast iron. In addition, it is common to add Co to cast iron to strengthen the material’s matrix. However, the wear resistance of cast iron can also be considerably affected by the addition of C, which is rarely discussed in the literature by the experts. Therefore, the effect of C content (1.0; 1.5; 2.0 wt.%) on the abrasive wear behavior of 5 wt.% V/Nb, Cr, Mo, W, and Co alloys was investigated in this study. An evaluation was conducted using a rubber wheel abrasion testing machine in accordance with ASTM G65 with silica sand (1100 HV; 300 μm) as abrasive particles. The results show that plural carbides (MC, M2C, and M7C3) precipitated on the microstructure of the material, which is not unlike the behavior of other types of carbides as the quantity of C increases. The hardness and wear resistance properties of 5V-5Cr-5Mo-5W-5Co-Fe and 5Nb-5Cr-5Mo-5W-5Co-Fe multicomponent cast alloys increased as the quantity of C increased. However, we observed no significant difference in the hardness between the two materials with the same C additions, while 5Nb presented better wear resistance properties compared to the 5V sample due to the larger size of NbC compared to VC. Therefore, it can be determined that, in this study, the size of the carbide plays a more important role than its volume fraction and hardness