• 제목/요약/키워드: Tian

검색결과 1,060건 처리시간 0.025초

Identifying Barriers Faced by Applicants without a Home Residency Program when Matching into Plastic Surgery

  • Steven L. Zeng;Gloria X. Zhang;Denisse F. Porras;Caitrin M. Curtis;Adam D. Glener;Andres Hernandez;William M. Tian;Emmanuel O. Emovon;Brett T. Phillips
    • Archives of Plastic Surgery
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    • 제51권1호
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    • pp.139-145
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    • 2024
  • Background Applying into plastic surgery (PS) is competitive. Lacking a home residency program (HRP) is another barrier. Our goal is to characterize challenges faced by PS applicants without HRPs and identify solutions. Methods Surveys were designed for current integrated PS residents and applicants in the 2022 Match without HRPs. Surveys were distributed electronically. Only U.S. allopathic graduate responses were included. Results Of 182 individuals surveyed, 74 responded (39%, 33 residents, 41 applicants). Sixty-six percent reported feeling disadvantaged due to lack of an HRP. Seventy-six percent of applicants successfully matched. Of these, 48% felt they required academic time off (research year) versus 10% of unmatched applicants. Ninety-seven percent of matched applicants identified a mentor versus 40% of unmatched applicants (p < 0.05). Matched applicants identified mentors through research (29%) and cold calling/emailing (25%). Matched versus unmatched applicants utilized the following resources: senior students (74 vs. 10%, p < 0.05) and social media (52 vs. 10%, p < 0.05). Among residents, 16 had PS divisions (48%). Thirty-six percent with divisions felt they had opportunities to explore PS, compared with 12% without divisions. Residents without divisions felt disadvantaged in finding research (94 vs. 65%, p < 0.05), delayed in deciding on PS (50 vs. 28%), and obtaining mentors (44 vs. 35%) and letters of recommendation (31 vs. 24%). Conclusion PS residents and applicants without HRPs reported feeling disadvantaged when matching. The data suggest that access to departments or divisions assists in matching. We identified that external outreach and research were successful strategies to obtain mentorship. To increase awareness for unaffiliated applicants, we should increase networking opportunities during local, regional, and national meetings.

Coronary CT Angiography with Knowledge-Based Iterative Model Reconstruction for Assessing Coronary Arteries and Non-Calcified Predominant Plaques

  • Tao Li;Tian Tang;Li Yang;Xinghua Zhang;Xueping Li;Chuncai Luo
    • Korean Journal of Radiology
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    • 제20권5호
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    • pp.729-738
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    • 2019
  • Objective: To assess the effects of iterative model reconstruction (IMR) on image quality for demonstrating non-calcific high-risk plaque characteristics of coronary arteries. Materials and Methods: This study included 66 patients (53 men and 13 women; aged 39-76 years; mean age, 55 ± 13 years) having single-vessel disease with predominantly non-calcified plaques evaluated using prospective electrocardiogram-gated 256-slice CT angiography. Paired image sets were created using two types of reconstruction: hybrid iterative reconstruction (HIR) and IMR. Plaque characteristics were compared using the two algorithms. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images and the CNR between the plaque and adjacent adipose tissue were also compared between the two reformatted methods. Results: Seventy-seven predominantly non-calcified plaques were detected. Forty plaques showed napkin-ring sign with the IMR reformatted method, while nineteen plaques demonstrated napkin-ring sign with HIR. There was no statistically significant difference in the presentation of positive remodeling, low attenuation plaque, and spotty calcification between the HIR and IMR reconstructed methods (all p > 0.5); however, there was a statistically significant difference in the ability to discern the napkin-ring sign between the two algorithms (χ2 = 12.12, p < 0.001). The image noise of IMR was lower than that of HIR (10 ± 2 HU versus 12 ± 2 HU; p < 0.01), and the SNR and CNR of the images and the CNR between plaques and surrounding adipose tissues on IMR were better than those on HIR (p < 0.01). Conclusion: IMR can significantly improve image quality compared with HIR for the demonstration of coronary artery and atherosclerotic plaques using a 256-slice CT.

Methanol-involved heterogeneous transformation of ginsenoside Rb1 to rare ginsenosides using heteropolyacids embedded in mesoporous silica with HPLC-MS investigation

  • Mengya Zhao;Yusheng Xiao;Yanyan Chang;Lu Tian;Yujiang Zhou;Shuying Liu;Huanxi Zhao;Yang Xiu
    • Journal of Ginseng Research
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    • 제48권4호
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    • pp.366-372
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    • 2024
  • Background: The biological activity and pharmacological effects of rare ginsenosides have been proven to be superior to those of the major ginsenosides, but they are rarely found in ginseng. Methods: Ginsenoside Rb1 was chemically transformed with the involvement of methanol molecules by a synthesized heterogeneous catalyst 12-HPW@MeSi, which was obtained by the immobilization of 12-phosphotungstic acid on a mesoporous silica framework. High-performance liquid chromatography coupled with mass spectrometry was used to identify the transformation products. Results: A total of 18 transformation products were obtained and identified. Methanol was found to be involved in the formation of 8 products formed by the addition of methanol molecules to the C-24 (25), C-20 (21) or C-20 (22) double bonds of the aglycone. The transformation pathways of ginsenoside Rb1 involved deglycosylation, addition, elimination, cycloaddition, and epimerization reactions. These pathways could be elucidated in terms of the stability of the generated carbenium ion. In addition, 12-HPW@MeSi was able to maintain a 60.5% conversion rate of Rb1 after 5 cycles. Conclusion: Tandem and high-resolution mass spectrometry analysis allowed rapid and accurate identification of the transformation products through the characteristic fragment ions and neutral loss. Rare ginsenosides with methoxyl groups grafted at the C-25 and C-20 positions were obtained for the first time by chemical transformation using the composite catalyst 12-HPW@MeSi, which also enabled cyclic heterogeneous transformation and facile centrifugal separation of ginsenosides. This work provides an efficient and recyclable strategy for the preparation of rare ginsenosides with the involvement of organic molecules.

Percutaneous Sacroplasty for Painful Sacral Metastases Involving Multiple Sacral Vertebral Bodies: Initial Experience with an Interpedicular Approach

  • Qing-Hua Tian;He-Fei Liu;Tao Wang;Ying-Sheng Cheng;Chun-Gen Wu
    • Korean Journal of Radiology
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    • 제20권6호
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    • pp.939-946
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    • 2019
  • Objective: To report our initial experience of percutaneous sacroplasty (PSP) with an interpedicular approach for treating painful sacral metastases involving multiple sacral vertebral bodies. Materials and Methods: This study prospectively enrolled 10 consecutive patients (six men and four women; mean age, 56.3 ± 13.8 years) who underwent PSP for painful sacral metastases involving multiple sacral vertebral bodies from March 2017 to September 2018. Visual analogue scale (VAS) scores, Oswestry disability index (ODI) values, and the number of opioids prescribed to the patients were assessed before and after PSP. The procedure duration, length of hospitalization, and complications were also recorded. Results: Mean VAS and ODI declined significantly from 6.90 ± 1.20 and 74.40 ± 5.48 before the procedure to 2.70 ± 1.34 and 29.60 ± 14.57 after the procedure, respectively (p < 0.01). The median number of opioids prescribed per patient decreased from 2 (interquartile range [IQR] 1-3) pre-procedure to 1 (IQR 0-3) post-procedure (p < 0.01). Nine of the 10 patients showed no or decreased opioid usage, and only 1 patient showed unchanged usage. The mean procedure duration was 48.5 ± 3.0 minutes. The average length of hospitalization was 4.7 ± 1.7 days. Extraosseous cement leakage occurred in three cases without causing any clinical complications. Conclusion: PSP with an interpedicular approach is a safe and effective treatment in patients with painful sacral metastases involving multiple sacral vertebral bodies and can relieve pain and improve mobility.

Structure-Activity Relationship and Functional Evaluation of Cannabinoid Type-1 Receptor

  • Shujie Wang;Xinru Tian;Suresh Paudel;Sungho Ghil;Choon-Gon Jang;Kyeong-Man Kim
    • Biomolecules & Therapeutics
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    • 제32권4호
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    • pp.442-450
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    • 2024
  • The type-1 cannabinoid receptor (CB1R) is a potential therapeutic target in several pathological conditions, including neuropsychological disorders and neurodegenerative diseases. Owing to their structural diversity, it is not easy to derive general structure-activity relationships (SARs) for CB1R ligands. In this study, CB1R ligands were classified into six structural families, and the corresponding SAR was determined for their affinities for CB1R. In addition, we determined their functional activities for the activation of extracellular signal-regulated kinases (ERKs). Among derivatives of indol-3-yl-methanone, the highest ligand affinity was observed when a pentyl and a naphthalenyl group were attached to the N1 position of the indole ring and the carbon site of the methanone moiety, respectively. In the case of adamantane indazole-3-carboxamide derivatives, the presence of fluorine in the pentyl group, the substituent at the N1 position of the indazole ring, strongly increased the affinity for CB1R. For (naphthalen-1-yl) methanone derivatives, the presence of 4-alkoxynaphthalene in the methanone moiety was more beneficial for the affinity to CB1R than that of a heterocyclic ring. The functional activities of the tested compounds, evaluated through ERK assay, were correlated with their affinity for CB1R, suggesting their agonistic nature. In conclusion, this study provides valuable insight for designing novel ligands for CB1R, which can be used to control psychiatric disorders and drug abuse.

Multi-modal Pedestrian Trajectory Prediction based on Pedestrian Intention for Intelligent Vehicle

  • Youguo He;Yizhi Sun;Yingfeng Cai;Chaochun Yuan;Jie Shen;Liwei Tian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권6호
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    • pp.1562-1582
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    • 2024
  • The prediction of pedestrian trajectory is conducive to reducing traffic accidents and protecting pedestrian safety, which is crucial to the task of intelligent driving. The existing methods mainly use the past pedestrian trajectory to predict the future deterministic pedestrian trajectory, ignoring pedestrian intention and trajectory diversity. This paper proposes a multi-modal trajectory prediction model that introduces pedestrian intention. Unlike previous work, our model makes multi-modal goal-conditioned trajectory pedestrian prediction based on the past pedestrian trajectory and pedestrian intention. At the same time, we propose a novel Gate Recurrent Unit (GRU) to process intention information dynamically. Compared with traditional GRU, our GRU adds an intention unit and an intention gate, in which the intention unit is used to dynamically process pedestrian intention, and the intention gate is used to control the intensity of intention information. The experimental results on two first-person traffic datasets (JAAD and PIE) show that our model is superior to the most advanced methods (Improved by 30.4% on MSE0.5s and 9.8% on MSE1.5s for the PIE dataset; Improved by 15.8% on MSE0.5s and 13.5% on MSE1.5s for the JAAD dataset). Our multi-modal trajectory prediction model combines pedestrian intention that varies at each prediction time step and can more comprehensively consider the diversity of pedestrian trajectories. Our method, validated through experiments, proves to be highly effective in pedestrian trajectory prediction tasks, contributing to improving traffic safety and the reliability of intelligent driving systems.

Physiological and transcriptome analysis of acclimatory response to cold stress in marine red alga Pyropia yezoensis

  • Li-Hong Ma;Lin Tian;Yu-Qing Wang;Cong-Ying Xie;Guo-Ying Du
    • ALGAE
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    • 제39권1호
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    • pp.17-30
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    • 2024
  • Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by ΦPSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the Fv/Fm and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

Time-varying characteristics analysis of vehicle-bridge interaction system using an accurate time-frequency method

  • Tian-Li Huang;Lei Tang;Chen-Lu Zhan;Xu-Qiang Shang;Ning-Bo Wang;Wei-Xin Ren
    • Smart Structures and Systems
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    • 제33권2호
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    • pp.145-163
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    • 2024
  • The evaluation of dynamic characteristics of bridges under operational traffic loads is a crucial aspect of bridge structural health monitoring. In the vehicle-bridge interaction (VBI) system, the vibration responses of bridge exhibit time-varying characteristics. To address this issue, an accurate time-frequency analysis method that combines the autoregressive power spectrum based empirical wavelet transform (AR-EWT) and local maximum synchrosqueezing transform (LMSST) is proposed to identify the time-varying instantaneous frequencies (IFs) of the bridge in the VBI system. The AR-EWT method decomposes the vibration response of the bridge into mono-component signals. Then, LMSST is employed to identify the IFs of each mono-component signal. The AR-EWT combined with the LMSST method (AR-EWT+LMSST) can resolve the problem that LMSST cannot effectively identify the multi-component signals with weak amplitude components. The proposed AR-EWT+LMSST method is compared with some advanced time-frequency analysis techniques such as synchrosqueezing transform (SST), synchroextracting transform (SET), and LMSST. The results demonstrate that the proposed AR-EWT+LMSST method can improve the accuracy of identified IFs. The effectiveness and applicability of the proposed method are validated through a multi-component signal, a VBI numerical model with a four-degree-of-freedom half-car, and a VBI model experiment. The effect of vehicle characteristics, vehicle speed, and road surface roughness on the identified IFs of bridge are investigated.

한국 장기체류 중국인 관광앱 사용경험: 샤오홍슈(Xiaohongshu) 앱 사례 (Tourism Experience Sharing of Long-term Living Chinese in South Korea: Case of Xiaohongshu App (RED))

  • 장티엔;장가령;구철모
    • 경영정보학연구
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    • 제25권2호
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    • pp.1-30
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    • 2023
  • 본 연구는 샤오홍슈 앱(RED app)을 이용하여 한국에 장기간 체류하는 중국인을 대상으로 설문조사를 실시하여 중국인의 한국 관광행위를 조사하고 분석하였다. 기억할만한 관광경험(MTEs: Memorable Tourism Experiences) 모델을 기반으로 몇 가지 변수를 추가하여 한국에서 장기간 체유하는 중국인의 여행 행동을 분석합니다. 최근 사용자 수가 많은 모바일 앱: 샤우홍슈(RED)의 이용자를 대상으로 조사했다. 212개의 유효한 표본분석을 통해 몇 가지 결론을 도출하였다. (1) 경치, 오락 및 정보성이 사람들의 여행 경험 공유에게 긍정적 영향을 주지만 상호작용 요인이 그렇지 않다는 결론을 발견하였다. (2) 여행 경험을 공유하는 행위는 여행 만족도와 다른 목적지에 방문하는 의도에 긍정적인 영향을 미치고 여행 만족도는 한국에 있는 다른 목적지에 방문하는 의도에 긍정적인 영향을 파악했다. 이 연구는 기억할만한 관광경험과 사용자 생성 콘텐츠(UGC: User-Generated Content) 모델을 결합하여 관광에 대한 문헌을 확장하여 외국인의 한국 관광행위에 관련하는 연구를 파악할 수 있다.

Experimental study on solidification of uranium tailings by microbial grouting combined with electroosmosis

  • Jinxiang Deng;Mengjie Li;Yakun Tian;Lingling Wu;Lin Hu;Zhijun Zhang;Huaimiao Zheng
    • Nuclear Engineering and Technology
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    • 제55권12호
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    • pp.4527-4542
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    • 2023
  • The present microbial reinforcement of rock and soil exhibits limitations, such as uneven reinforcement effectiveness and low calcium carbonate generation rate, resulting in limited solidification strength. This study introduces electroosmosis as a standard microbial grouting reinforcement technique and investigates its solidification effects on microbial-reinforced uranium tailings. The most effective electroosmosis effect on uranium tailings occurs under a potential gradient of 1.25 V/cm. The findings indicate that a weak electric field can effectively promote microbial growth and biological activity and accelerate bacterial metabolism. The largest calcium carbonate production occurred under the gradient of 0.5 V/cm, featuring a good crystal combination and the best cementation effect. Staged electroosmosis and electrode conversion efficiently drive the migration of anions and cations. Under electroosmosis, the cohesion of uranium tailings reinforced by microorganisms increased by 37.3% and 64.8% compared to those reinforced by common microorganisms and undisturbed uranium tailings, respectively. The internal friction angle is also improved, significantly enhancing the uniformity of reinforcement and a denser and stronger microscopic structure. This research demonstrates that MICP technology enhances the solidification effects and uniformity of uranium tailings, providing a novel approach to maintaining the safety and stability of uranium tailings dams.