X-ray and ultra violet photoelectron spectroscopy are used to observe the interface electronic states at the GaN (0001) and high-κ dielectric interfaces. The GaN is aqueous HCl cleaned prior to atomic layer deposition of Al2O3 and HfO2, then followed by a post deposition anneal. The GaN/HfO2 and GaN/Al2O3 interfaces exhibited dipoles of 1.6 eV and 0.4 eV, respectively. It is found that the formation of an interfacial layer at the GaN/HfO2 interface is the primary cause of the larger dipole.

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Introduction. Incidence of breast cancer (BC) in 2020 is about 2.26 million new cases. It is the first common cancer accounting for 11.7% of all cancer worldwide. Disease complications and the mortality rate of breast cancer are highly dependent on the early diagnosis. Therefore, novel human breast-imaging techniques play an important role in minimizing the breast cancer morbidity and mortality rate. Electrical impedance tomography (EIT) is a noninvasive technique to image the breast using the electrical impedance behavior of the body tissues. Objectives. The aims of this manuscript are as follows: (1) a comprehensive investigation of the accuracy of EIT for breast cancer diagnosis through searching pieces of evidence in the valid databases and (2) meta-analyses of the results. Methods. The systematic search was performed in the electronic databases including PubMed, Web of Science, EMBASE, Science Direct, ProQuest, Scopus, and Google Scholar without time and language limitation until January 2021. Search terms were “EIT” and “Breast Cancer” with their synonyms. Relevant studies were included based on PRISMA and study objectives. Quality of studies and risk of bias were performed by QUADAS-2 tools. Then, relevant data were extracted in Excel form. The hierarchical/bivariate meta-analysis was performed with “metandi” package for the ROC plot of sensitivity and specificity. Forest plot of the Accuracy index and double arcsine transformations was applied to stabilize the variance. The heterogeneity of the studies was evaluated by the forest plots, χ2 test (assuming a significance at the a-level of 10%), and the I2 statistic for the Accuracy index. Results. A total of 4027 articles were found. Finally, 12 of which met our criteria. Overall, these articles included studies of 5487 breast cancer patients. EIT had an overall pooled sensitivity and specificity of 75.88% (95% CI, 61.92% to 85.89%) and 82.04% (95% CI, 69.72% to 90.06%), respectively. The pooled diagnostic odds ratio was 14.37 (95% CI, 6.22% to 33.20%), and the pooled effect of accuracy was 0.79 with 95% CI (0.73, 0.83). Conclusions. This study showed that EIT can be used as a useful method alongside mammography. EIT sensitivity could not be compared with the sensitivity of MRI, but in terms of specificity, it can be considered as a new method that probably can get more attention. Furthermore, large-scale studies will be needed to support the evidence.

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Electrical Impedance Tomography (EIT) is a non-invasive technique utilized in various medical applications, including brain imaging and other neurological diseases. EIT is one of the modern medical imaging techniques which use surface measurements for reconstruction of the conductivity distribution of a cross-section. Recognizing the physiological and anatomical characteristics of organs based on their electrical properties is one of the main applications of EIT, as each variety of tissue structures has individual electrical characteristics. The high potential of brain EIT in real-time supervision and early recognition of cerebral brain infarction, hemorrhage, and other diseases established. Many studies are performed on EIT, although the available information is incohesive and inconclusive, which is most likely the reason for such an effective technology being dormant and not used routinely. In this investigation, we review the studies performed on neurological applications of EIT to provide the researchers with sufficient information for a probable more comprehensive research in the future. In this study we found that EIT is a very useful device for brain imaging, capturing fast electrical activities in the brain, imaging epileptic seizure, detecting intracranial bleeding, detecting Cerebral Edema, and diagnosing stroke.