phase increment
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2021 ◽  
Author(s):  
Yanfen Lan ◽  
Lixun Chen ◽  
Shaobin Chen ◽  
Mingping Ma

Abstract Objectives: The aim of this study was to investigate the diagnostic value of computerized tomography (CT) features of small intestinal stromal tumors in terms of their degree of risk. Methods: The clinical data and CT data of 107 patients with small intestinal stromal tumors confirmed by surgery and pathology in our hospital from June 2012 to October 2020 were selected. According to the results of postoperative pathological risk, the patients were divided into high-risk and low-risk groups, wherein 67 cases were in high-risk group and 40 cases were in the low-risk group The maximum diameter, solid component plain scan, arterial phase CT value, venous phase CT value, and delayed phase CT value of the two groups were measured, and the enhancement degree of arterial phase, venous phase, delayed CT value, and lesion enhancement mode were calculated. The difference between the two groups was compared. An independent sample t-test was used to compare quantitative indices, and the chi-squared test or Fisher’s exact test was used for qualitative index comparison. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of the arterial phase CT value, venous phase CT value, delayed phase CT value, arterial phase enhancement degree, venous phase enhancement degree, delayed phase enhancement degree, and the enhanced net value-added in the risk degree of SBGISTs. The relationship between preoperative imaging findings and tumor risk was retrospectively analyzed. Results: Univariate analysis showed that there were significant differences in the lesion location, growth pattern, lesion ulcer, necrotic cystic degeneration, lobulation, boundary with surrounding tissues, plain scan density and lesion enhancement mode, CT value in arterial phase, increment in arterial phase, CT value in venous phase, increment in venous phase, CT value in delayed phase, increment in delayed phase, and enhancement value in lesion between the two groups (P < 0.05); there were no significant differences in sex, age, calcification, bleeding, clinical symptoms, and CT value (P > 0.05). The ROC curve analysis showed that the area under the curve (AUC) of the long diameter of the lesion was 0.959 (P = 0.000), the optimal critical point of the ROC curve was the lesion ≥ 4.80 cm, the sensitivity was 88.1%, the specificity was 97.5%, and the accuracy was 91.6%; for the low-risk group, the AUC was 0.788 (the largest, P = 0.000), the sensitivity was 77.5%, the specificity was 70.1%, and the accuracy was 72.9%. Multivariate analysis showed that non-uniform density (P = 0.030; odds ratio [OR]: 12.544; 95% confidence interval [CI]: 1.269–123.969), arterial phase CT value (P = 0.024; OR: 10.790; 95% CI: 1.374–84.754), and lesion length (P = 0.000; OR: 648.694; 95% CI: 40.541–10,379.714) were risk factors for SBGISTs. Conclusions: The CT features of small intestinal stromal tumors have certain characteristics, which can help to grade the risk of small intestinal stromal tumors before surgery.


2021 ◽  
Vol 317 ◽  
pp. 517-522
Author(s):  
Mohamed Kamal El-Fawkhry ◽  
Ayman Mohamed Fathy ◽  
Ahmed El-Sherbiny

Tempcore process considers the widest process that is being used in the production of reinforced steel rebar. The normal tempcore process is fundamentally dependent on the amount of latent heat in the core of the steel rebar, and the cooling rate of the rebar cross-section. Cooled water box and the cooling bed have a powerful effect on the cooling rate of the steel rebar. This research has been designed to monitor the continuous cooling transformation CCT diagram of steel rebar with different two contents of residual elements. Moreover, the effect of the cooling bed’s conditions has been simulated to identify the effect of cooling rate at the cooling bed step on the microstructure, as well as the hardness value of the produced steel rebar. It was found that the cooling rate at the cooling bed step has a great powerful effect on the produced steel rebar in term of bainite phase increment, and the hardness value as well.


Author(s):  
Kamran Heydari ◽  
Ali Akbar Tahaei ◽  
Akram Pourbakht ◽  
Hamid Haghani ◽  
Ahmadreza Nazeri

Abstract Background Temporal resolution is essential to speech acoustic perception. However, it may alter in individuals with auditory disorders, impairing the development of spoken and written language. The envelope of speech signals contains amplitude modulation (AM) that has critical information. Any problem reducing the listener's sensitivity to these amplitude variations (auditory temporal acuity) is likely to cause speech comprehension problems. The modulation detection threshold (MDT) test is a measure for evaluating temporal resolution. However, this test cannot be used for patients with poor cooperation; therefore, objective evaluation of MDT is essential. Purpose The main aim of this study is to find the association between the auditory steady-state response (ASSR) and psychoacoustic measurement of MDT at different intensity levels and to assess the amplitude and phase of ASSR as a function of modulation depth. Design This was a correlational research. Study Sample Eighteen individuals (nine males and nine females) with normal hearing sensitivity, aged between 18 and 23 years, participated in this study. Data Collection and Analysis ASSR was recorded at fixed AM rates and variable AM depths for carrier frequencies of 1,000 and 2,000 Hz with varying intensities. The least AM depth, efficient to evoke an ASSR response, was interpreted as the physiological detection threshold of AM. The ASSR amplitude and phase, as a function of AM depth, were also evaluated at an intensity level of 60 dB hearing level (HL) with modulation rates of 40 and 100 Hz. Moreover, the Natus instrument (Biologic Systems) was used for the electrophysiological measurements. An AC40 clinical audiometer (Intra-acoustic, Denmark) was also used for the psychoacoustic measurement of MDT in a similar setting to ASSR, using the two-alternative forced choice method. Pearson's correlation test and linear regression model and paired t-test were used for statistical analyses. Results A significant positive correlation was found between psychoacoustic and electrophysiological measurements at a carrier frequency of 1000 Hz, with a modulation rate of 40 Hz at intensity levels of 60 dB HL (r = 0.63, p = 0.004), 50 dB HL (r = 0.52, p = 0.02). A significant positive correlation was also found at a carrier frequency of 2000 Hz, with a modulation rate of 47 Hz at 60 dB HL (r = 0.55, p = 0.01) and 50 dB HL (r = 0.67, p = 0.002) and a modulation rate of 97 Hz at 60 dB HL (r = 0.65, p = 0.003). Moreover, a significant association was found between the modulation depth and ASSR amplitude and phase increment at carrier frequencies of 1,000 and 2000 Hz, with modulation rates of 40 and 100 Hz. Conclusion There was a significant correlation between ASSR and behavioral measurement of MDT, even at low intensities with low modulation rates of 40 and 47 Hz. The ASSR amplitude and phase increment was a function of modulation depth increase. The findings of this study can be used as a basis for evaluating the relationship between two approaches in the clinical population.


2015 ◽  
Vol 742 ◽  
pp. 27-31
Author(s):  
Hai Lei Zhao ◽  
Ping Song ◽  
Chuang Bo Hao

Firefly-inspired synchronicity method using reackback response is effective with existence of message delay. We introduce a weighted factor based on RSSI into the phase increment calculation. Besides, different coupling strength parameters are selected according to the degree of synchronicity to achieve a good balance between synchronicity speed and accuracy. Simulink module is constructed and the results prove that this method shows great resistance against random variation of the message delay within an acceptable range.


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