De novo design of a novel AIE fluorescent probe tailored to autophagy visualization via pH manipulation

Huang Xueyan,Chen Fei,Ma Yeshuo,Zheng Fan,Fang Yanpeng,Feng Bin,Huang Shuai,Zeng Hongliang,Zeng Wenbin 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Macroautophagy is an essential cellular self-protection mechanism, and defective autophagy has been considered to contribute to a variety of diseases. During the process, cytoplasmic components are transported via autophagosomes to acidic lysosomes for metabolism and recycling, which represents application niches for lysosome-targeted fluorescent probes. Additionally, in view of the complexity of the autophagy pathway, it entails more stringent requirements for probes suitable for monitoring autophagy. Meanwhile, aggregation-induced emission (AIE) fluorescent probes have been impressively demonstrated in the biomedical field, which bring fascinating possibilities to the autophagy visualization.We reported a generalizable de novo design of a novel pH-sensitive AIE probe ASMP-AP tailored to lysosome targeting for the interpretation of autophagy. Firstly, the theoretical calculation was carried out followed by the investigation of optical properties. Then, the performance of ASMP-AP in visualizing autophagy was corroborated by starvation or drugs treatments. Furthermore, the capability of ASMP-AP to monitor autophagy was demonstrated in ex vivo liver tissue and zebrafish in vivo.ASMP-AP displays a large stokes shift, great cell permeability and good biocompatibility. More importantly, ASMP-AP enables a good linear response to pH, which derives from the fact that its aggregation state can be manipulated by the acidity. It was successfully applied for imaging autophagy in living cells and was proved capable of monitoring mitophagy. Moreover, this novel molecular tool was validated by ex vivo visualization of activated autophagy in drug-induced liver injury model. Interestingly, it provided a meaningful pharmacological insight that the melanin inhibitor 1-phenyl-2-thiourea (PTU)-induced autophagy was clearly presented in wild-type zebrafish.ASMP-AP offers a simple yet effective tool for studying lysosome and autophagy. This is the first instance to visualize autophagy in zebrafish using a small-molecule probe with AIE characters, accurate lysosome targeting and simultaneous pH sensitivity. Ultimately, this novel fluorescent system has great potential for in vivo translation to fuel autophagy research.

영상프로브를 이용한 화염 정면 가시화

신재익(Jaeik Shin),진병대(Byoungdae Jin),현동기(Dongki Hyun) 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.12

본 논문은 국방과학연구소 엔진 시험장에 설치된 영상프로브에 대해 다루고 있다. 영상프로브는 엔진의 후단, 디퓨저 상단에 설치되어 있으며 잠만경 모양의 관 형상을 띄고 있어서 페리스코프라 불린다. 페리스코프는 엔진 후단의 열기(2000 °C) 및 연소 생성물 등의 영향을 받아서 파손 위험이 높다. 따라서 CFD 해석을 통해 장치의 냉각 성능을 검증하였다. 또한 시험을 통해 연료 유량에 대한 장치 내부의 온도를 비교하여 장치의 내구성을 확인하였다. 현재의 설계에서 영상프로브를 통하여 화염 형상 및 노즐 제어, 배출 유동의 안정성을 가시적으로 확인 가능하다. This paper describes an imaging probe device installed in ADD engine test facility. The imaging probe is installed at the rear end of the engine and top of the diffuser. The device is so-called periscope because its figure looks like a pipe of periscope. The periscope has a high risk of breakage due to the influence of heat(2000 °C) at the rear end of the engine and combustion products. Therefore, through CFD analysis, we verified cooling performance of the device. Also, through tests, we verified durability of the device by comparing temperature and fuel mass flow rate. In the current design, using imaging probe, we can see flame shapes, control of nozzle, and stability of exhaust flow visually.

Visualization and Flowfield Measurements of the Vortical Flow over a Double-Delta Wing

Sohn, Myong-Hwan,Jang, Young-IL The Korean Society for Aeronautical and Space Scie 2003 International Journal of Aeronautical and Space Sc Vol.4 No.1

The vortical flow of a 65-deg flat plate delta wing with a leading edge extension(LEX) was examined through off-surface visualization, 5-hole probe and hot-film measurements. The off-surface flow visualization technique used micro water droplets generated by a home-style ultrasonic humidifier and a laser beam sheet. The angles of attack ranged from 10 to 30 degrees, and the sideslip angles ranged from 0 to -15 degrees. The Reynolds number was $1.82{\times}10^5$ for the flow visualization, and $1.76{\times}10^6$ for the 5-hole probe and hot-film measurements. The comparison of the visualization photos and the flow field measurement showed that the two results were in a good agreement for the relative position and the structure of the wing and LEX vortices, even though the flow Reynolds numbers of the two results were much different. The wing vortex and the LEX vortex coil each other while maintaining a comparable strength and identity at zero sideslip. Neither a looping of the wing vortex around the strake vortex, nor the lopsided coiling of the stronger strake and the weaker wing vortices was observed. At non-zero sideslip, the downward movement of the LEX vortex when going downstream was enhanced on the windward side, and the downward and inboard movement of the LEX vortex when going downstream was suppressed on the leeward side. The counterclockwise coiling of the wing and LEX vortices was decreased significantly on the leeward side.

Ratiometric and discriminative visualization of autophagic processes with a novel dual-responded lysosome-specific fluorescent probe

Fan Zheng,Yeshuo Ma,Jipeng Ding,Shuai Huang,Shengwang Zhang,Xueyan Huang,Bin Feng,Hongliang Zeng,Fei Chen,Wenbin Zeng 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Autophagy is a critical self-eating pathway involved in numerous physiological and pathological processes. Lysosomal degradation of dysfunctional organelles and invading microorganisms is central to the autophagy mechanism and essential for combating disease-related conditions. Therefore, monitoring fluctuations in the lysosomal microenvironment is vital for tracking the dynamic process of autophagy. Although much effort has been put into designing probes for measuring lysosomal viscosity or pH separately, there is a need to validate the concurrent imaging of the two elements to enhance the understanding of the dynamic progression of autophagy. Methods Probe HFI was synthesized in three steps and was developed to visualize changes in viscosity and pH within lysosomes for real-time autophagy tracking. Then, the spectrometric determination was carried out. Next, the probe was applied to image autophagy in cells under nutrient-deprivation or external stress. Additionally, the performance of HFI to monitor autophagy was employed to evaluate acetaminophen-induced liver injury. Results We constructed a ratiometric dual-responsive probe, HFI, with a large Stokes shift over 200 nm, dualwavelength emission, and small background interference. The ratiometric fluorescent signal (R = I610/I460) of HFI had an excellent correlation with both viscosity and pH. More importantly, high viscosity and low pH had a synergistic promotion effect on the emission intensity of HFI, which enabled it to specially lit lysosomes without disturbing the inherent microenvironment. We then successfully used HFI to monitor intracellular autophagy induced by starvation or drugs in real-time. Interestingly, HFI also enabled us to visualize the occurrence of autophagy in the liver tissue of a DILI model, as well as the reversible effect of hepatoprotective drugs on this event. Conclusions In this study, we developed the first ratiometric dual-responsive fluorescent probe, HFI, for real-time revealing autophagic details. It could image lysosomes with minimal perturbation to their inherent pH, allowing us to track changes in lysosomal viscosity and pH in living cells. Ultimately, HFI has great potential to serve as a useful indicator for autophagic changes in viscosity and pH in complex biological samples and can also be used to assess drug safety.

가치 중심적 HCI를 위한 새로운 방법론의 개발 및 적용

이인성(Inseong Lee),최보름(Boreum Choi),김진우(Jinwoo Kim),이기호(Kiho Lee),정승기(Seungki Jung) 한국HCI학회 2007 한국HCI학회 논문지 Vol.2 No.1

지금까지 HCI분야의 많은 연구들은 사용성 (Usability)을 중요한 연구 주제로 인식하여 왔다. 그러나 연구의 범위를 사용성에 한정하는 것은 HCI 분야의 잠재성을 좁히고, 사용자 경험 (User Experience)의 개념도 좁은 범위로 한정시키게 된다. 따라서 향후 HCI 분야의 연구는 정보 기술의 사용성 측면의 뿐만 아니라, 정보 기술의 사용을 통한 다양한 사용자 경험을 구조적인 관점에서 살펴보아야 한다. 즉 사용성 중심의 연구가 아닌, 보다 전반적이고 구조적인 측면에서 사용자 경험을 살펴보는 새로운 방향의 HCI 연구가 필요할 것으로 보인다. 이와 같이 사용자 경험을 보다 전반적이고 구조적인 측정에서 이해하기 위해서는 사용자가 특정 정보 기술의 사용을 통해 추구하는 가치(Value)와 그와 같은 가치를 실현 시킬 수 있는 정보 기술의 속성 (Attribute) 및 결과 (Consequence), 그리고 속성, 결과, 가치 간 연관 관계를 구조적인 측면에서 살펴보아야 한다. 이를 위하여 본 연구는 사용자 가치에 대한 대표적인 이론인 Means-End Chain Theory와 속성, 결과, 가치 간 연관 관계를 파악하기 위한 정성적 연구 방법론인 Laddering 기법을 기반으로 사용자 경험 구조 파악 및 가치 중심적 HCI (Value-Centered HCI)를 위한 새로운 연구 방법론을 제안하고자 한다. 또한 본 연구에서는 새롭게 제안된 방법론을 통해 모바일 인터넷 서비스에 대한 사용자 경험 구조를 도출하고, 모바일 인터넷 상황에서 도출된 결과 및 본 연구에서 새롭게 제안된 방법론의 이론적이고 실용적인 의의를 제시하고자 한다. For many years, human-computer interaction (HCI) practitioners have focused on usability in order to enhance the user experience, and companies have seen it as an area where they can gain advantages over their competitors. However, a focus on usability limits the potential of HCI research because it restricts the concept of user experience to just an implemented functionality of the information technology (IT). Therefore, it is necessary to expand the boundary of user experience research into a holistic dimension. We suggest that one of the most powerful ways to broadly understand user experience with an IT is to investigate the attributes of an IT and users’ perceived values and to construct a user experience structure, a hierarchical structure between the attributes of an IT and users’ perceived values. This study thus undertakes two research tasks: to develop a specific methodology, which is the visual probing, for constructing a user experience structure with the attributes of an IT and users" perceived values, and then to build a user experience structure practically by conducting a case study to a specific IT: mobile data service.

광섬유 탐침과 고속가시화 기법을 이용한 원형탱크 내부의 기포직경 및 상승속도 측정

김규락(Gyurak Kim),최성환(Seong Whan Choi),김윤기(Yoon Kee Kim),김경천(Kyung Chun Kim) 한국가시화정보학회 2012 한국가시화정보학회지 Vol.10 No.2

An optical fiber probe system for measuring the local void fraction in the air-water two-phase flow was developed with a 1550 nm light source. Air was injected through a nozzle placed in the center of the bottom wall of a water-filled cylindrical tank. The optical fiber probe having a diameter of 125 μm was sufficiently thin to resolve the air-water interface of the bubbly flows. To verify the performance of the optical fiber probe, the synchronized high speed visualization study using a high speed camera was carried out. Comparison between the optical signals and the instantaneous bubble diffraction images confirms that the optical fiber probe is very accurate to measure the void fraction in two-phase flows. The estimated bubble diameter and the rising velocity by the optical fiber probe have 1% and 5% of accuracy, respectively.

상징적 공간 탐사 기법을 이용한 상향적 및 하향적 주의 효과 측정

옥애니,김민식 한국뇌학회 2001 한국뇌학회지 Vol.1 No.1

상징적 공간 탐사과제를 이용하여 시각적 주의의 상향적 및 하향적 요소를 3개의 실험을 통하여 측정하였다. 실험 1에서는 탐사자극 이전에 돌발자극을 제시하여 주의가 상향적으로 유도되도록 조작하였으며, 실험 2에서는 1차 탐색과제로 단순 색으로 정의된 표적자극과 방해자극을 제시하여 주의의 상향적 효과와 하향적 효과 모두를 측정하였으며, 실험 3에서는 탐색과제에서 탐색자극의 상향적 정보 차이를 최소화한 채 하향적 효과를 주로 측정하였다. 실험결과, 상향적 및 하향적 주의효과가 상징적 공간 탐사 기법을 통하여 측정 가능함이 나타났으며, 기존의 연구 결과와 유사한 방식으로 이 두 기제의 시간적 및 공간적 작용 방식에 각기 차이가 있음을 보였다. 이러한 결과는 공간적 주의가 아날로그적 공간 표상 뿐 아니라 상징적인 공간 표상과 같은 다양한 공간 표상 수준에서 작동할 가능성을 시사해 준다. Three experiments were performed to examine bottom-up and top-down attentional effects, using a symbolic spatial probe task. Experiment 1 measured bottom-up factors. Probe responses were faster when the arrow pointed to an abrupt onset location than to blank locations, indicating that symbolic spatial representation is affected by the bottom-up activation of an abrupt onset stimulus. In experiment 2, both top-down and bottom-up attentional effects were measured. Probe results showed that the target location received more attention with both SOA conditions (133msec and 317msec). In experiment 3, we measured top-down control of attention, and found again the benefit of the target location, but only with the long-SOA condition (317msec). The symbolic spatial task in the current study could measure the bottom-up and top-down mechanisms of visual attention that develop differently over time and space. Moreover, these results suggest that spatial attention operates on many different spatial representations such as a symbolic spatial representation as well as an analogical spatial representation.

Precise visualization and ROS-dependent photodynamic therapy of colorectal cancer with a novel mitochondrial viscosity photosensitive fluorescent probe

Runsha Xiao,Fan Zheng,Kuo Kang,Lei Xiao,Anyao Bi,Yiting Chen,Qi Zhou,Xueping Feng,Zhikang Chen,Hao Yin,Wei Wang,Zihua Chen,Xiaomiao Cheng,Wenbin Zeng 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Colorectal cancer (CRC) is a prominent global cancer with high mortality rates among human beings. Efficient diagnosis and treatment have always been a challenge for CRC management. Fluorescence guided cancer therapy, which combines diagnosis with therapy into one platform, has brought a new chance for achieving precise cancer theranostics. Among this, photosensitizers, applied in photodynamic therapy (PDT), given the integration of real-time imaging capacity and efficacious treatment feasibility, show great potential to serve as remarkable tools. Although much effort has been put into constructing photosensitizers for locating and destroying CRC cells, it is still in high need to develop novel photosensitizers to attain specific detection and fulfil effective therapy. Methods Probe HTI was rational synthesized for the diagnosis and treatment of CRC. Spectrometric determination was carried out first, followed by the 1O2 generation ability test. Then, HTI was displayed in distinguishing CRC cells from normal cells Further, the PDT effect of the photosensitizer was studied in vitro. Additionally, HTI was used in CRC BALB/c nude mice model to validate its viscosity labelling and tumor suppression characteristics. Results We successfully fabricated a mitochondrial targeting probe, HTI, together with remarkable viscosity sensitivity, ultralow background interference, and excellent 1O2 generation capacity. HTI was favorably applied to the viscosity detection, displaying a 11-fold fluorescent intensity enhancement in solvents from 1.57 cp to 2043 cp. Then, it was demonstrated that HTI could distinguish CRC cells from normal cells upon the difference in mitochondrial viscosity. Moreover, HTI was qualified for producing 1O2 with high efficiency in cells, supported by the sparkling signals of DCFH after incubation with HTI under light irradiation. More importantly, the viscosity labelling and tumor suppression performance in CRC CDX model was determined, enriching the multifunctional validation of HTI in vivo. Conclusions In this study, HTI was demonstrated to show a sensitive response to mitochondrial viscosity and possess a high 1O2 generation capacity. Both in vitro cell imaging and in vivo tumor treatment trials proved that HTI was effectively served as a robust scaffold for tumor labeling and CRC cells clearance. This breakthrough discovery held immense potential for advancing the early diagnosis and management of CRC through PDT. By leveraging HTI’s properties, medical professionals could benefit from improved diagnostic accuracy and targeted treatment in CRC management, ultimately leading to enhanced patient outcomes.

가치 중심적 HCI를 위한 새로운 방법론의 개발: 모바일 인터넷 서비스의 사용자 경험 구조를 중심으로

김진우,홍세준,Glenn E. Mayhew,George M. Giaglis,Elizabeth Fife,Kar Yan TAM,Minna Mattila 한국 HCI학회 2007 한국HCI학회 논문지 Vol.00 No.-

Comparative study of hydrodynamic characteristics with respect to direction of installation of gas-liquid ejector system

최성환,지호성,김경천 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8

The gas-liquid two-phase ejector is a device without moving parts, in which a liquid is used to drive a gas of a low-pressure source. Inthis study, the effect of the direction of installation on hydrodynamic characteristics was examined using the same air/water ejector loop. The entrained air flow rates and local void fraction profiles were also measured at various water flow rates for three types of installation:horizontal, vertical-upward, and vertical-downward, and were compared. From the study, the vertical-downward installation was foundto be the best in terms of air entrainment ratio and homogeneity of bubbles.