Denoising magnetic resonance images using collaborative non-local means

Chen, Geng,Zhang, Pei,Wu, Yafeng,Shen, Dinggang,Yap, Pew-Thian Elsevier 2016 Neurocomputing Vol.177 No.-

<P><B>Abstract</B></P> <P>Noise artifacts in magnetic resonance (MR) images increase the complexity of image processing workflows and decrease the reliability of inferences drawn from the images. It is thus often desirable to remove such artifacts beforehand for more robust and effective quantitative analysis. It is important to preserve the integrity of relevant image information while removing noise in MR images. A variety of approaches have been developed for this purpose, and the non-local means (NLM) filter has been shown to be able to achieve state-of-the-art denoising performance. For effective denoising, NLM relies heavily on the existence of repeating structural patterns, which however might not always be present within a single image. This is especially true when one considers the fact that the human brain is complex and contains a lot of unique structures. In this paper we propose to leverage the repeating structures from <I>multiple</I> images to <I>collaboratively</I> denoise an image. The underlying assumption is that it is more likely to find repeating structures from multiple scans than from a single scan. Specifically, to denoise a target image, multiple images, which may be acquired from different subjects, are spatially aligned to the target image, and an NLM-like block matching is performed on these aligned images with the target image as the reference. This will significantly increase the number of matching structures and thus boost the denoising performance. Experiments on both synthetic and real data show that the proposed approach, collaborative non-local means (CNLM), outperforms the classic NLM and yields results with markedly improved structural details.</P>

Analysis on Temperature Distribution and Current-Carrying Capacity of GIL Filled with Fluoronitriles-CO₂ Gas Mixture

Geng Chen,Youping Tu,Cong Wang,Yi Cheng,Han Jiang,Hongyang Zhou,Hua Jin 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

Fluoronitriles-CO₂ gas mixtures are promising alternatives to SF6 in environmentallyfriendly gas-insulated transmission lines (GILs). Insulating gas heat transfer characteristics are of major significance for the current-carrying capacity design and operational state monitoring of GILs. In this paper, a three-dimensional calculation model was established for a GIL using the thermal-fluid coupled finite element method. The calculated results showed close agreement with experimentally measured data. The temperature distribution of a GIL filled with the Fluoronitriles-CO₂ mixture was obtained and compared with those of GILs filled with CO₂ and SF6. Furthermore, the effects of the mixture ratio of the component gases and the gas pressure on the temperature rise and current-carrying capacity of the GIL were analyzed. Results indicated that the heat transfer performance of the Fluoronitriles-CO₂ gas mixture was better than that of CO₂ but worse than that of SF₆. When compared with SF6, use of the Fluoronitriles-CO₂ gas mixture caused a reduction in the GIL’s current-carrying capacity. In addition, increasing the Fluoronitriles gas component ratio or increasing the pressure of the insulating gas mixture could improve the heat dissipation and current-carrying capacity of the GIL. These research results can be used to design environmentally-friendly GILs containing Fluoronitriles-CO₂ gas mixtures.

Educational Technology Training for Faculty Members in Chinese Higher Education Institutions: Status and Directions

Geng Chen,Huiyu Zhang,Ronghuai Huang APEC국제교육협력원 2006 Asia-Pacific Cybereducation Journal Vol.2 No.1

A survey of staff members of higher education institutions across China at which educational technology training programs had been conducted indicated that the great majority of respondents were using educational technology in their work, although a smaller proportion felt that they had the necessary knowledge and skills to do so efficiently and effectively. The most common skills mastered were basic computer operations, Web searching, and the use of presentation software. Skills that are more integrally related to effective student learning and cost-efficient operation, such as course management and evaluation and integration of technology with lessons, were mastered only by a small minority. Respondents recommended that future training take the form of blended learning, combining face-to-face format with distance learning and self-study, and that it emphasize practical skills and direct application to the participant’s work. Other recommendations are also made regarding the establishment of standards for educational technology competencies and the improvement of evaluation of training courses.

Effects of Narrative Exposure Therapy for Treating Depressive and Anxious Disorders: A Systematic Review and Meta-Analysis

Chen Geng,Miao Zhang,Lily Zhang,Hai Yin,Suyun Wang 대한신경정신의학회 2024 PSYCHIATRY INVESTIGATION Vol.21 No.4

Objective Narrative exposure therapy (NET) has been used in various contexts for the treatment of the effects of trauma, with promising results in clinical trials. However, its effects on anxiety and depression are still unclear. The present study is a systematic review and meta-analysis of the effects of NET on depression and anxiety.Methods The Embase, Cumulative Index of Nursing and Allied Health Literature, PubMed, Web of Science core collection, Cochrane Library, Chinese National Knowledge Infrastructure, Chinese Biomedical Database, and Wangfang databases were searched from the earliest records to March 2023. Two researchers independently screened the literature, extracted data, evaluated the risk of bias, and cross-checked the data. Meta-analysis was performed using the program RevMan 5.3.Results Eleven randomized controlled trials with a total of 754 participants were included in the study. The results showed that NET reduced both the depression (standard mean difference [SMD]=-0.51, 95% confidence interval [CI] -0.73–-0.29, p<0.00001) and anxiety (SMD=-0.65, 95% CI -1.13–-0.18, p=0.007) scores of the patients. Furthermore, NET was found to alleviate negative emotions associated with guilt (mean difference [MD]=-3.60, 95% CI -5.52–-1.68, p=0.0005) and negative change (MD=-5.80, 95% CI -9.76–-1.83, p=0.004).Conclusion This analysis showed that NET can alleviate depression and anxiety. It may thus be used in clinical settings to alleviate patients’ negative feelings and aid their overall recovery.

Surgical Treatment for Early Esophageal Squamous Cell Carcinoma

Chen, Shao-Bin,Weng, Hong-Rui,Wang, Geng,Yang, Jie-Sheng,Yang, Wei-Ping,Liu, Di-Tian,Chen, Yu-Ping,Zhang, Hao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

More studies are needed to clarify treatments and prognosis of early esophageal squamous cell carcinoma (ESCC). This retrospective study was designed to review the outcome of surgical treatment for early ESCC, evaluate the results of a left thoracotomy for selected patients with early ESCC, and identify factors affecting lymph node metastases and survival. The clinicopathological data of 228 patients with early ESCC who underwent transthoracic esophagectomy with lymphadenectomy without preoperative adjuvant treatment were reviewed. The ${\chi}^2$ test or Fisher's exact test were used to detect factors related to lymph node metastasis. Univariate and multivariate analyses were performed to identify prognostic factors. There were 152 males and 76 females with a median age of 55 years. Two hundred and eight patients underwent a left thoracotomy, and the remaining 20 patients with lymph nodes in the upper mediastinum more than 5 mm in short-axis diameter by computed tomography scan underwent a right thoracotomy. No lymph node metastasis was found in the 18 patients with carcinoma in situ, while lymph node metastases were detected in 1.6% (1/62) of patients with mucosal tumours and 18.2% (27/148) of patients with submucosal tumours. Only 7 patients showed upper mediastinal lymph node metastases in the follow-up. The 5- and 10-year overall survival rates were 81.4% and 70.1%, respectively. Only histologic grade (P<0.001) and pT category (P=0.001) significantly correlated with the presence of lymph node metastases. In multivariate analysis, only histologic grade (P=0.026) and pT category (P=0.008) were independent prognostic factors. A left thoracotomy is acceptable for selected patients with early ESCC. Histologic grade and pT category affected the presence of lymph node metastases and were independent prognostic factors for early ESCC.

A New Method for Elimination of Zero-Sequence Voltage in Dual Three-Level Inverter Fed Open-End Winding Induction Motors

Geng, Yi-Wen,Wei, Chen-Xi,Chen, Rui-Cheng,Wang, Liang,Xu, Jia-Bin,Hao, Shuang-Cheng The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

Due to the excessive zero-sequence voltage in dual three-level inverter fed open-end winding induction motor systems, zero-sequence circumfluence which is harmful to switching devices and insulation is then formed when operating in a single DC voltage source supplying mode. Traditionally, it is the mean value instead of instantaneous value of the zero-sequence voltage that is eliminated, through adjusting the durations of the operating vectors. A new strategy is proposed for zero-sequence voltage elimination, which utilizes unified voltage modulation and a decoupled SVPWM strategy to achieve two same-sized equivalent vectors for an angle of $120^{\circ}$, generated by two inverters independently. Both simulation and experimental results have verified its efficiency in the instantaneous value elimination of zero-sequence voltage.

Altered Expression of Substance P and NK1R in CCR3+ and CD123+HLA-DR− Basophils Under Airway Allergic Conditions

Geng Shiyang,Xie Hua,Chen Liping,Chen Dong,Lu Sijing,Zhao Nan,Yang Ruiming,Wang Zhao,He Shaoheng,Zhang Huiyun 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.6

Purpose: To explore expression of SP and NK1R in basophils of allergic asthma (AA), allergic rhinitis (AR) and AR combined with AA (ARA), and influence of allergens and immunoglobulin E (IgE) mediated mechanisms on SP and NK1R expression. Methods: Expression of SP and NK1R was detected by flow cytometry, NK1R mRNA expression was detected by real time quantitative polymerase chain reaction (qPCR), and mouse AR and AA models were employed for in vivo study. Results: SP+ and NK1R+ cells increased in CCR3+ and CD123+HLA-DR− granulocytes of AA. PPE elevated proportions of SP+ cells in CCR3+ and CD123+HLA-DR− granulocytes, whereas ASWE and HDME augmented SP+ cells in CD123+HLA-DR− granulocytes of AR and ARA patients. ASWE, HDME and PPE increased proportions of NK1R+ cells in CCR3+ PBMC and CD123+HLA-DR− granulocytes of AR patients. OVA, Der p1, IL-33, IL-37, IgE and SP enhanced NK1R expression on KU812 cells. NK1R expressing basophils were increased in blood of OVA sensitized and challenged AR and AA mice. FcεRI-KO AA mice seemed to have less NK1R+ basophils than WT AA mice in their blood. Conclusion: CCR3+ and CD123+HLA-DR− cells are likely involved in AA and AR via SP and NK1R. IgE-related mechanism may participate in upregulation of NK1R expression.

Analysis on Temperature Distribution and Current-Carrying Capacity of GIL Filled with Fluoronitriles-CO₂ Gas Mixture

Chen, Geng,Tu, Youping,Wang, Cong,Cheng, Yi,Jiang, Han,Zhou, Hongyang,Jin, Hua The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.6

Fluoronitriles-$CO_2$ gas mixtures are promising alternatives to $SF_6$ in environmentally-friendly gas-insulated transmission lines (GILs). Insulating gas heat transfer characteristics are of major significance for the current-carrying capacity design and operational state monitoring of GILs. In this paper, a three-dimensional calculation model was established for a GIL using the thermal-fluid coupled finite element method. The calculated results showed close agreement with experimentally measured data. The temperature distribution of a GIL filled with the Fluoronitriles-$CO_2$ mixture was obtained and compared with those of GILs filled with $CO_2$ and $SF_6$. Furthermore, the effects of the mixture ratio of the component gases and the gas pressure on the temperature rise and current-carrying capacity of the GIL were analyzed. Results indicated that the heat transfer performance of the Fluoronitriles-$CO_2$ gas mixture was better than that of $CO_2$ but worse than that of $SF_6$. When compared with $SF_6$, use of the Fluoronitriles-$CO_2$ gas mixture caused a reduction in the GIL's current-carrying capacity. In addition, increasing the Fluoronitriles gas component ratio or increasing the pressure of the insulating gas mixture could improve the heat dissipation and current-carrying capacity of the GIL. These research results can be used to design environmentally-friendly GILs containing Fluoronitriles-$CO_2$ gas mixtures.

Differential Protein Expression Profile Between CD20 Positive and Negative Cells of the NCI-H929 Cell Line

Geng, Chuan-Ying,Liu, Nian,Yang, Guang-Zhong,Liu, Ai-Jun,Leng, Yun,Wang, Hui-Juan,Li, Li-Hong,Wu, Yin,Li, Yan-Chen,Chen, Wen-Ming Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

At present, multiple myeloma (MM) remains an incurable disease and cologenic cells may be responsible for disease relapse. It has been proposed that CD20+/CD138- NCI-H929 cells could be hallmarks of MM clonogenic cells. Here, the immunology phenotype of NCI-H929 cells is described. Only a small population of CD20+/CD138- cells (<1%) was found in the NCI-H929 cell line, but CD20+/CD138- cells were not detected. We found that CD20+/CD138+ cells were able to exhibit cologenic capacity by colony formation assay and continuous passage culture. Proteins were analyzed by 1D-SDS-PAGE and TMT based quantitative differential liquid chromatography tandem mass spectrometry (LC-MS/MS). 1,082 non-redundant proteins were identified, 658 of which were differentially expressed with at least a 1.5-fold difference. 205 proteins in CD20+ cells were expressed at higher levels and 453 proteins were at lower levels compared with CD20- cells. Most proteins had catalytic and binding activity and mainly participated in metabolic processes, cell communication and molecular transport. These results proved that there are different biological features and protein expression profile between CD20+ and CD20- cells in the NCI-H929 cell line.

역사문화경관 이미지가 치유특질에 미치는 영향 - 경주시 양동마을을 중심으로 -

천겅 ( Chen Geng ),이선호 ( Lee Sun-ho ),이영경 ( Yi Young-kyoung ) 한국전통조경학회(구 한국정원학회) 2021 한국전통조경학회지 Vol.39 No.2

집중력회복 이론(ART)에 의하면 인간이 치유특질을 가진 경관을 경험하면 의도적인 집중력으로 유발된 정신적 피로감이 치유될 수 있다. ART에서는 다양한 경관이 치유특질을 가질 수 있다고 인정하고, 경관의 네 가지 치유특질은 지각강도가 클수록 치유효과가 강해진다고 설명하였다. 지금까지 치유경관에 대한 연구는 주로 자연경관과 도시경관을 대상으로 연구되어 왔다. 본 연구의 연구목적은 다음과 같다. 첫째, RCS를 이용하여 양동마을 경관을 대상으로 치유특질을 평가하고, 치유특질이 대상지경관의 방문 선호도에 미치는 영향을 조사하고자 한다. 둘째, 양동마을경관을 대상으로 경관이미지를 평가하여, 경관이미지가 경관의 치유특질에 미치는 영향을 조사하는 것이다. 본 연구의 대상지는 경주시 양동마을이며, 127명의 대학생이 설문조사에 참여하였다. 그리고 경관 이미지를 분석하기 위한 SD 16항목, 치유특질을 평가하기 위한 Laumann (2001)의 RCS 22항목을 측정도구로 사용하였다. 연구결과는 다음과 같이 요약한다. 첫째, SD법을 통해 양동마을의 경관 이미지를 분석하였으며, 양동마을 경관 이미지에 대한 요인분석 결과는 장소성 요인과 특이성 요인으로 도출되었다. 둘째, RCS의 신뢰성과 타당성을 입증하고 있으며, 요인분석 결과 세가지 요인이 추출되었다. 셋째, 경관 이미지가 RCS의 세 가지 치유특질에 긍정적인 영향이 있는 것으로 나타났다. 넷째, 도출된 RCS의 세 가지 치유특질이 방문선호도에 긍정적인 영향을 미치는 것으로 나타났으며, 상대적인 방문선호도에 미치는 영향력의 순서는 매력ㆍ적합, 탈출감, 공간감으로 분석되었다. 앞으로의 연구에서는 RCS의 신뢰성을 재검증하기 위한 연구가 필요하다. 또한, 다양한 경관유형을 대상으로 경관 이미지를 분석하여 치유특질에 미치는 영향을 구체적으로 파악하는 것도 필요하다고 판단된다. According to the theory of concentration recovery(ART), experiencing landscapes with healing properties can heal human mental fatigue caused by intentional concentration. The ART illustrates four healing qualities of the landscape. ART admits that various landscapes can have healing properties, the four healing properties of the landscape explained that the greater the perceptual strength, the stronger the healing effect. Until now, research on healing landscapes has been mainly done on natural and urban landscapes. The purpose of this study is as follows. First, eIt is intended to evaluate the healing characteristics of the Yangdong village landscape using RCS and investigate the impact of the healing characteristics on the visiting preference of the target landscape. Second, Evaluating the landscape image of Yangdong Village landscape, Investigating the effect of landscape images on the healing properties of landscape. This study was conducted in Yangdong Village, Gyeongju, 127 college students participated in the survey. SD 16 items to analyze landscape images and RCS 22 items from Laumann(2001) to evaluate healing properties were used as measurement tools. The findings are summarized as follows. First, The landscape image of Yangdong Village was analyzed through SD method, the analysis of the factors of Yangdong Village landscape image results in two factors: place and singularity. Second, It demonstrates the reliability and validity of RCS, Three factors were extracted from the factor analysis results. Third, Landscape images have a positive effect on the three healing characteristics of RCS. Fourth, Three healing properties of RCS have been shown to have a positive effect on visiting preferences, The order of influence on the relative visiting preferences was analyzed as attractiveness, fit, sense of escape, and sense of space. The findings suggest that future work requires research to re-validate the reliability of RCS. It is also necessary to analyze landscape images for various landscape types to specifically understand the effects on healing characteristics.