10 documents found, page 1 of 1
Photodynamic therapy review: principles, photosensitizers, applications, and fu...
Correia, J. H.; Rodrigues, José Artur Oliveira; Pimenta, Sara Filomena Ribeiro; Dong, Tao; Yang, ZhaochuPhotodynamic therapy (PDT) is a minimally invasive therapeutic modality that has gained great attention in the past years as a new therapy for cancer treatment. PDT uses photosensitizers that, after being excited by light at a specific wavelength, react with the molecular oxygen to create reactive oxygen species in the target tissue, resulting in cell death. Compared to conventional therapeutic modalities, PDT ...
A dynamic threshold cancellation technique for a high-power conversion efficien...
Godinho, António; Yang, Zhaochu; Dong, Tao; Gonçalves, L. M.; Mendes, P. M.; Wen, Yumei; Li, Ping; Jiang, ZhuangdePower conversion efficiency (PCE) has been one of the key concerns for power management circuits (PMC) due to the low output power of the vibrational energy harvesters. This work reports a dynamic threshold cancellation technique for a high-power conversion efficiency CMOS rectifier. The proposed rectifier consists of two stages, one passive stage with a negative voltage converter, and another stage with an act...
A CMOS current starved VCO for energy harvesting applications
Almeida, Gonçalo F. F.; Yang, Zhaochu; Mendes, P. M.; Dong, TaoThis work presents a current starved voltage-controlled oscillator based on standard 0.13μm CMOS process. Integrated within a power management circuit, the proposed oscillator provides an average periodic signal with a frequency of 84.81kHz. Additionally, to assure a stable periodic signal from the environmental instability a voltage reference is designed. The proposed architecture makes full use of subthreshol...
A low-power two-stage active rectifier for energy harvesting applications
Ferreira, Ana C. R.; Carvalho, Rui; Yang, Zhaochu; Correia, J. H.; Dong, TaoThis paper presents a new architecture of a two-stage active rectifier suitable for energy harvesting applications. The two-stage structure can be separated firstly into a passive stage, including one negative voltage converter, and secondly, an active stage that consists of a NOT gate used to drive the active diode switch. The rectifier is fully designed and simulated using 0.13 mu m CMOS technology. The circu...
PDMS microlenses for focusing light in narrow band imaging diagnostics
Costa, Adriana Clotilde; Pimenta, Sara; Ribeiro, J. F.; Silva, Manuel Fernando Ribeiro; Wolffenbuttel, Reinoud F.; Dong, Tao; Yang, ZhaochuMinimally invasive medical devices can greatly benefit from Narrow Band Imaging (NBI) diagnostic capabilities, as different wavelengths allow penetration of distinct layers of the gastrointestinal tract mucosa, improving diagnostic accuracy and targeting different pathologies. An important performance parameter is the light intensity at a given power consumption of the medical device. A method to increase the i...
Drinking water quality monitoring: An alternative approach to microbial contami...
Simaes, Joao C.G.; Dong, Tao; Yang, Yili; Silva, Carlos A.The nonstop growing of world population and consequent increase in water demands, as raise the interest in continuous and real-time drinking water monitoring systems. The following study aims to study Tryptophan Intrinsic Fluorescence as a method for detecting microbial contamination events in drinking water.
LED optrode with integrated temperature sensing for optogenetics
Goncalves, S. Beatriz; Palha, José Marinho Cruz; Fernandes, Helena C.; Souto, Márcio R.; Pimenta, Sara; Dong, Tao; Yang, Zhaochu; Ribeiro, J. F.In optogenetic studies, the brain is exposed to high-power light sources and inadequate power density or exposure time can cause cell damage from overheating (typically temperature increasing of 2 ∘ C). In order to overcome overheating issues in optogenetics, this paper presents a neural tool capable of assessing tissue temperature over time, combined with the capability of electrical recording and optical stim...
Monitoring aquaculture water quality: Design of an early warning sensor with Al...
Silva, Luís F. B. A.; Yang, Zhaochu; Pires, Nuno M. M.; Dong, Tao; Teien, Hans-Christian; Storebakken, Trond; Salbu, BritA novel toxicity-warning sensor for water quality monitoring in recirculating aquaculture systems (RAS) is presented. The design of the sensor system mainly comprises a whole-cell biosensor. <i>Aliivibrio fischeri</i>, a luminescent bacterium widely used in toxicity analysis, was tested for a mixture of known fish-health stressors, namely nitrite, un-ionized ammonia, copper, aluminum and zinc. Two toxicity pred...
Modification of microfluidic paper-based devices with dye nanomaterials obtaine...
Bertão, Ana Raquel; Pires, Nuno; Fonseca, António M.; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Dong, Tao; Neves, Isabel C.Zeolite nanostructures were used as hosts for dyes normally used in some bioassays (pH and protein), and applied on microfluidic paper-based analytical devices (PADs). The obtained dye nanomaterials were characterized by several techniques (structural (FTIR and XRD), surface (SEM/EDX), textural (N2 adsorption) analyses and dye loading determination by TGA analysis), to confirm the stability of both host and gue...
Design of a microfluidic paper-based device for analysis of biomarkers from uri...
Couto, Adriana; Dong, TaoAmong all infections, urinary tract infections (UTI) are one of the most common. Nowadays the procedures to analyze urine and consequently detect UTI are often painful and time-consuming. Recent studies about microfluidic paper-based devices have developed the interest of researchers due their outstanding characteristics. In this paper is presented a novel design for a microfluidic paper-based device for screen...