ABSTRACT
Low-toxicity gold nanoclusters-decorated Ag@SiO2 (Au NCs-Ag@SiO2) nanocomposites modified plasmonic photoelectrodes were first fabricated to improve the photoelectric properties of Au NCs and practical application in biological detection. Through adjusting distance between Au NCs and plasmonic silver nanoparticles (Ag NPs), the photocurrent intensity of Au NCs enhanced by 3.8 times attributed to strong competition between enhancement functions of hot electron transfer, local electric field, light scattering effects, and quenching functions of nonradiative energy transfer. Further comparison between experimental results and theoretical simulations were conducted to gain a deeper understanding toward the photoelectric enhancement mechanism. Moreover, Au NCs-Ag@SiO2 nanocomposites was successfully applied to the construction of photoelectrochemical (PEC) biosensors for sensitively detecting alkaline phosphatase activity. This proposed PEC biosensor showed a wide linear range from 0.04 to 400 U·L-1, and a low detection limit of 0.022 U·L-1.
Subject(s)
Alkaline Phosphatase/analysis , Biosensing Techniques , Electrochemical Techniques , Gold/chemistry , Metal Nanoparticles/chemistry , Alkaline Phosphatase/metabolism , Humans , Particle Size , Photochemical Processes , Silicon Dioxide/chemistry , Silver/chemistry , Surface PropertiesABSTRACT
Ultrasound (US)-guided needle operation is usually used to visualize both tissue and needle position such as tissue biopsy and localized drug delivery. However, the transducer-needle orientation is limited due to reflection of the acoustic waves. We proposed a leaky acoustic wave method to visualize the needle position and orientation. Laser pulses are emitted on top of the needle to generate acoustic waves; then, these acoustic waves propagate along the needle surface. Leaky wave signals are detected by the US array transducer. The needle position can be calculated by phase velocities of two different wave modes and their corresponding emission angles. In our experiments, a series of needles was inserted into a tissue mimicking phantom and porcine tissue to evaluate the accuracy of the proposed method. The results show that the detection depth is up to 51 mm and the insertion angle is up to 40° with needles of different diameters. It is demonstrated that the proposed approach outperforms the conventional B-mode US-guided needle operation in terms of the detection range while achieving similar accuracy. The proposed method reveals the potentials for further clinical applications.
Subject(s)
Image-Guided Biopsy/methods , Lasers , Needles , Ultrasonography, Interventional/methods , Animals , Equipment Design , Image-Guided Biopsy/instrumentation , Phantoms, Imaging , Signal Processing, Computer-Assisted , Sound , Swine , Ultrasonography, Interventional/instrumentationABSTRACT
BACKGROUND: Human parainfluenza viruses (HPIV) 1-4 had been analyzed as being one of the most frequent causes of hospitalizations for young children with respiratory tract illnesses. METHODS: This retrospective study was performed from children virologically confirmed as HPIV infection through throat swab or nasopharyngeal aspirates at a tertiary care university hospital, between January 2012 and December 2014. HPIV4 was not checked and analyzed, due to not include in the commercial kit. The demographic, epidemiological, clinical presentations, diagnosis, treatment, outcomes, and laboratory data were analyzed. RESULTS: Totally 398 cases were enrolled, including 39 (9.8%) of HPIV1, 67 (16.8%) of HPIV2, and 292 (73.4%) of HPIV3. The mean age of HPIV-infected children was 2.9 year-old, and 50.5% were among one to three year-old. A total of 56.8% HPIV3-infected children were among one to three years old, however, no HPIV2-infected children was younger than one year-old. The HPIV1-infected patients were more common to develop wheezing and diagnose as acute bronchiolitis. HPIV2-infected children were more likely to have hoarseness (23.9%), and were associated with croup (25.4%). HPIV3 was isolated from two fatal cases, with neurological underlying diseases. CONCLUSION: The impact caused by HPIVs infections is significant in hospitalized children. In the current study, our results contribute to the epidemiologic, clinical and laboratory information of HPIV infection in children in the important areas of respiratory tract infection that could support the development of optimization management.
