IEEE Transactions on Pattern Analysis and Machine Intelligence

Reactive oxygen species (ROS) play an essential role in regulating various physiological functions of living organisms. The intrinsic biochemical properties of ROS, which underlie the mechanisms ne...

Reactive Oxygen Species (ROS)-Based Nanomedicine.

Photodynamic therapy (PDT) has been applied to treat a wide range of medical conditions, including wet age-related macular degeneration psoriasis, atherosclerosis, viral infection and malignant cancers. However, the tissue penetration limitation of excitation light hinders the widespread clinical use of PDT. To overcome this “Achilles' heel”, deep PDT, a novel type of phototherapy, has been developed for the efficient treatment of deep-seated diseases. Based on the different excitation sources, including near-infrared (NIR) light, X-ray radiation, and internal self-luminescence, a series of deep PDT techniques have been explored to demonstrate the advantages of deep cancer therapy over conventional PDT excited by ultraviolet-visible (UV-Vis) light. In particular, the featured applications of deep PDT, such as organelle-targeted deep PDT, hypoxic deep PDT and deep PDT-involved multimodal synergistic therapy are discussed. Finally, the future development and potential challenges of deep PDT are also elucidated for clinical translation. It is highly expected that deep PDT will be developed as a versatile, depth/oxygen-independent and minimally invasive strategy for treating a variety of malignant tumours at deep locations.

Overcoming the Achilles' heel of photodynamic therapy.

From bench to bedside

The ability of dual- and multi-energy CT to differentiate materials of different effective atomic numbers makes possible several new and clinically relevant CT applications.

Dual- and Multi-Energy CT: Principles, Technical Approaches, and Clinical Applications

Photodynamic therapy (PDT), using a combination of chemical photosensitizers (PS) and light, has been successfully applied as a noninvasive therapeutic procedure to treat tumors by inducing apoptosis or necrosis of cancer cells. However, most current clinically used PS have suffered from the instability in physiological conditions which lead to low photodynamic therapy efficacy. Herein, a highly biocompatible poly(dopamine) (PDA) nanoparticle conjugated with Chlorin e6 (referenced as the PDA-Ce6 nanosphere) was designed as a nanotherapeutic agent to achieve simultaneous photodynamic/photothermal therapy (PDT/PTT). Compared to the free Ce6, the PDA-Ce6 nanosphere exhibited significantly higher PDT efficacy against tumor cells, because of the enhanced cellular uptake and subsequently greater reactive oxygen species (ROS) production upon laser irradiation at 670 nm. Meanwhile, the PDA-Ce6 nanosphere could be also used as a photoabsorbing agent for PTT, because of the excellent photothermal conversion ability...

Chlorin e6 Conjugated Poly(dopamine) Nanospheres as PDT/PTT Dual-Modal Therapeutic Agents for Enhanced Cancer Therapy.

Purpose: To objectively characterize the performance of the gemstone spectral imaging (GSI) mode of GE CT750 HD scanner from a user's perspective. Methods: A regular scan protocol that approximates the adult abdomen scan protocol frequently used in the authors' institute was selected as the baseline, and a GSI protocol (preset 11) that is similar to the regular protocol and has a moderate dose level (CTDI{sub vol}=26.27 mGy) was compared to the baseline protocol. The resolving power of both protocols was characterized in terms of modulation transfer functions and high contrast resolution bar readings. Their noise characteristics were studied through noise power spectra, and their low contrast detectability was compared via contrast-to-noise ratio. Material decomposition capability of GSI was evaluated by scanning iodine solutions of 9-24 mg/ml iodine concentration in a Gammex CT phantom and by examining the estimated iodine concentration. In addition, a formula describing the dependency of HU in iodine enhanced area on GSI monochromatic energies and iodine concentrations was provided and the theoretical values were compared with the measured results. Results: The resolutions levels of 50%, 10%, and 5% MTF of GSI monochromatic images at 65 keV agree with those of the regular protocol within 0.1 lp/cm. GSImore » monochromatic images at 65 keV demonstrated the lowest noise level among GSI images of different monochromatic energies and showed very similar noise magnitude and noise power distribution as compared to the regular protocol images. The CNR of 60 and 65 keV GSI monoimages are approximately 100% of those of the regular protocol images. Estimated iodine concentration levels agreed with the actual values within 2% when the iodine solutions were placed at 3, 9, 12 o'clock positions of the phantom; when iodine solutions were placed at the phantom center and at 6 o'clock position, higher discrepancies of 2%-10% were observed. The observed dependency of HU on keV and iodine concentration levels agreed with the expectation from x-ray attenuations. Conclusions: Equivalent performances were observed in the comparison between GSI 65 keV monochromatic images and images from a regular abdomen scan protocol. This suggests the possibility of GSI to be employed in routine abdominal scans, which would potentially offer more information through its capabilities of material decomposition.« less

Objective characterization of GE Discovery CT750 HD scanner: Gemstone spectral imaging mode

Traditionally, offline modeling and simulation has been the tool of choice for improving wind energy system control strategies and their utility system integration. This paper exploits how a newly established real-time hardware-in-the-loop (HIL) test facility, which is designed for testing all-electric ship propulsion systems, can be utilized for wind energy research. The test site uses two 2.5-MW/220-rpm dynamometers and a 5-MW variable voltage and frequency converter to emulate a realistic dynamic environment, both mechanically and electrically. The facility is controlled by a digital real-time electric power system simulator that is capable of simulating electrical networks and control systems of substantial complexity, typically with a 50-mus time step. Substantial input/output allows the feedback of measured quantities into the simulation. A 15-kW mock-up motor-generator set is used to demonstrate some critical aspects of the concept including the implementation of a proposed neural-network-based sensorless maximum wind energy capture control. From the dynamic test results presented, it is concluded that the proposed system shows great potential for the development of a unified wind energy design, test, and research platform

Development of a Unified Design, Test, and Research Platform for Wind Energy Systems Based on Hardware-in-the-Loop Real-Time Simulation

Multifunctional theranostic nanoparticles represent an emerging agent with the potential to offer extremely sensitive diagnosis and targeted cancer therapy. Herein, we report the synthesis and characterization of a multifunctional theranostic agent (referred to as LA-LAPNHs) for targeted magnetic resonance imaging/computed X-ray tomography (MRI/CT) dual-mode imaging and photothermal therapy of hepatocellular carcinoma. The LA-LAPNHs were characterized as having a core–shell structure with the gold nanoparticles (AuNPs)@polydopamine (PDA) as the inner core, the indocyanine green (ICG), which is electrostatically absorbed onto the surface of PDA, as the photothermal therapeutic agent, and the lipids modified with gadolinium–1,4,7,10-tetraacetic acid and lactobionic acid (LA), which is self-assembled on the outer surface as the shell. The LA-LAPNHs could be selectively internalized into the hepatocellular cell line (HepG2 cells) but not into HeLa cells due to the specific recognition ability of LA to asialog...

Lipid-AuNPs@PDA Nanohybrid for MRI/CT Imaging and Photothermal Therapy of Hepatocellular Carcinoma

We showed that virtual monochromatic reconstruction of dual-energy unenhanced head CT scans at 65 keV for supratentorial brain and at 75 keV for the posterior fossa maximizes image quality compared with that of conventional polychromatic CT.

https://pubs.rsna.org/doi/pdf/10.1148/radiol.12111604

Virtual monochromatic reconstruction of dual-energy unenhanced head CT at 65-75 keV maximizes image quality compared with conventional polychromatic CT.

Da Zhang

Papers

Chlorin e6 Conjugated Poly(dopamine) Nanospheres as PDT/PTT Dual-Modal Therapeutic Agents for Enhanced Cancer Therapy.

Objective characterization of GE Discovery CT750 HD scanner: Gemstone spectral imaging mode

Development of a Unified Design, Test, and Research Platform for Wind Energy Systems Based on Hardware-in-the-Loop Real-Time Simulation

Lipid-AuNPs@PDA Nanohybrid for MRI/CT Imaging and Photothermal Therapy of Hepatocellular Carcinoma

Virtual monochromatic reconstruction of dual-energy unenhanced head CT at 65-75 keV maximizes image quality compared with conventional polychromatic CT.