Wireless power and communication system for medical implants

This thesis aims to examine the hypothesis that “Power of more than 1 mW can be received by the microsystem inside a human body through a wireless magnetic coupling link with a receiver of a diameter less than 2mm from a transfer distance as much as 20 cm” and “Data can be transmitted wirelessly from the microsystem to an external reader using the same magnetic coupling link as the wireless power system”. A 3-coil weakly coupled magnetic resonance wireless power transfer system has been built based on solenoid coils. The design of the transmitter of the system includes the designs of a single-turn coupling coil and a multi-turn primary coil. To maximise the magnetic field generated by the transmitter, the relative position of the two coils is optimised to match the impedances of the coils. Design flow is reported for the optimum dimensional parameters (coil diameter, gap interval, number of turns) of the primary coil after a detailed analysis of the co-dependencies of the parameters. The design of the receiver of the system includes the designs of the receiver coil and the rectifier. Two kinds of solenoid receiver coils have been analysed, the air-core coil and the ferrite-core coil. Due to the size limitation (2 mm-diameter) of the receiver, only the ferrite-core solenoid coil is able to meet the power demand. Design flow of the ferrite-core coil is reported. In terms of the rectifier, a novel static gate-control bootstrapping rectifier (static BSR) and a novel opto-coupled dynamic gate-control (OCDGC) bootstrapping rectifier are reported, which have low power consumption and high power conversion efficiency compared with junction-diode rectifiers and comparator-based rectifiers. The power delivered to load (PDL) of the whole WPT system is tested in air and human conductive tissue at transfer distances within 20 cm with consideration of rectifier power conversion efficiencies and different load conditions (500 Ω and 5 kΩ). Results show that, at 20 cm transfer distance, the system will be able to meet the 1 mW power demand for light load condition (5 kΩ) both in air and in human conductive tissue; But in heavy load condition (500 Ω), a high number of receiver coil turns will be needed to meet the power demand. The sensitivity of the data transfer of the whole WPT system is also analysed based on load shift keying (LSK) modulation. The S-parameter S11 ratio is the Figure of Merit (FOM) of the data transfer analysis. It can be concluded that the hypotheses of the thesis are feasible, which is an inspiration of multiple deep-tissue micro-implants for medical purposes

Differential microRNA expression between shoots and rhizomes in Oryza longistaminata using high-throughput RNA sequencing

AbstractPlant microRNAs (miRNAs) play important roles in biological processes such as development and stress responses. Although the diverse functions of miRNAs in model organisms have been well studied, their function in wild rice is poorly understood. In this study, high-throughput small RNA sequencing was performed to characterize tissue-specific transcriptomes in Oryza longistaminata. A total of 603 miRNAs, 380 known rice miRNAs, 72 conserved plant miRNAs, and 151 predicted novel miRNAs were identified as being expressed in aerial shoots and rhizomes. Additionally, 99 and 79 miRNAs were expressed exclusively or differentially, respectively, in the two tissues, and 144 potential targets were predicted for the differentially expressed miRNAs in the rhizomes. Functional annotation of these targets suggested that transcription factors, including squamosa promoter binding proteins and auxin response factors, function in rhizome growth and development. The expression levels of several miRNAs and target genes in the rhizomes were quantified by RT-PCR, and the results indicated the existence of complex regulatory mechanisms between the miRNAs and their targets. Eight target cleavage sites were verified by RNA ligase-mediated rapid 5′ end amplification. These results provide valuable information on the composition, expression and function of miRNAs in O. longistaminata, and will aid in understanding the molecular mechanisms of rhizome development

Systematic Investigation of Novel, Controlled Low‐Temperature Sintering Processes for Inkjet Printed Silver Nanoparticle Ink

Functional inks enable manufacturing of flexible electronic devices by means of printing technology. Silver nanoparticle (Ag NP) ink is widely used for printing conductive components. A sintering process is required to obtain sufficient conductivity. Thermal sintering is the most commonly used method, but the heat must be carefully applied to avoid damaging low-temperature substrates such as polymer films. In this work, two alternative sintering methods, damp heat sintering and water sintering are systematically investigated for inkjet-printed Ag tracks on polymer substrates. Both methods allow sintering polyvinyl pyrrolidone (PVP) capped Ag NPs at 85°C. In this way, the resistance is significantly reduced to only 1.7 times that of the samples on polyimide sintered in an oven at 250°C. The microstructure of sintered Ag NPs is analyzed. Taking the states of the capping layer under different conditions into account, the explanation of the sintering mechanism of Ag NPs at low temperatures is presented. Overall, both damp heat sintering and water sintering are viable options for achieving high conductivity of printed Ag tracks. They can broaden the range of substrates available for flexible electronic device fabrication while mitigating substrate damage risks. The choice between them depends on the specific application and the substrate used

Cortical Areas Associated With Mismatch Negativity: A Connectivity Study Using Propofol Anesthesia

Auditory mismatch negativity (MMN) is an event-related potential (ERP) waveform induced by rare deviant stimuli that occur in a stream of regular auditory stimuli. The generators of MMN are believed to include several different cortical regions like the bilateral temporal and the right inferior frontal gyrus (IFG). However, exact cortical regions associated with MMN remain controversial. In this study, we compared the number of long-distance connections induced by the standard and deviant stimuli during awake state and propofol anesthesia state to identify the cortical areas associated with the generation of MMN. In awake state, we find that deviant stimuli synchronize more information between the right frontal and temporal than standard stimuli. Moreover, we find that the deviant stimuli in awake state activate the bilateral frontal, central areas, the left temporal and parietal areas as compared to the anesthesia state, whereas the standard stimuli do not. These results suggest that, in addition to the bilateral temporal and the right IFG, the bilateral frontal and centro-parietal regions also contribute to the generation of MMN

Evaluating the Individualized Treatment of Traditional Chinese Medicine: A Pilot Study of N-of-1 Trials

Purpose. To compare the efficacy of individualized herbal decoction with controlled decoction for individual patients with stable bronchiectasis. Methods. We conducted N-of-1 RCTs (single-patient, double-blind, randomized, multiple crossover design) in 3 patients with stable bronchiectasis. The primary outcome was patient self-rated symptom scores on visual analogue scales. Secondary outcome was 24-hour sputum volume. A clinical efficacy criterion which combined symptoms score and medication preference was also formulated. Results. All three patients showed various degrees of improvement on their symptoms and one patient’s (Case 3) 24 h sputum volume decreased from 70 mL to 30 mL. However, no significant differences were found between individualized herbal decoction and control decoction on symptoms score, or on 24-hour sputum volume. One patient (Case 2) had clear preference for the individualized herbal decoction over the standard one with the confirmation after unblinding. We therefore considered this case as clinically important. Discussion. N-of-1 trials comply with individualized philosophy of TCM clinical practice and had good compliance. It is necessary to set up clinical efficacy criteria and to consider the interference of acute exacerbation

Cardiovascular involvement in Epstein–Barr virus infection

Cardiovascular involvement is an uncommon but severe complication of Epstein–Barr virus (EBV) infection caused by direct damage and immune injury. Recently, it has drawn increasing attention due to its dismal prognosis. It can manifest in various ways, including coronary artery dilation (CAD), coronary artery aneurysm (CAA), myocarditis, arrhythmias, and heart failure, among others. If not treated promptly, cardiovascular damage can progress over time and even lead to death, which poses a challenge to clinicians. Early diagnosis and treatment can improve the prognosis and reduce mortality. However, there is a lack of reliable large-scale data and evidence-based guidance for the management of cardiovascular damage. Consequently, in this review, we attempt to synthesize the present knowledge of cardiovascular damage associated with EBV and to provide an overview of the pathogenesis, classification, treatment, and prognosis, which may enhance the recognition of cardiovascular complications related to EBV and may be valuable to their clinical management

Identification of loci affecting teat number by genome-wide association studies on three pig populations

Objective Three genome-wide association studies (GWAS) and a meta-analysis of GWAS were conducted to explore the genetic mechanisms underlying variation in pig teat number. Methods We performed three GWAS and a meta-analysis for teat number on three pig populations, including a White Duroc×Erhualian F2 resource population (n = 1,743), a Chinese Erhualian pig population (n = 320) and a Chinese Sutai pig population (n = 383). Results We detected 24 single nucleotide polymorphisms (SNPs) that surpassed the genome-wide significant level on Sus Scrofa chromosomes (SSC) 1, 7, and 12 in the F2 resource population, corresponding to four loci for pig teat number. We highlighted vertnin (VRTN) and lysine demethylase 6B (KDM6B) as two interesting candidate genes at the loci on SSC7 and SSC12. No significant associated SNPs were identified in the meta-analysis of GWAS. Conclusion The results verified the complex genetic architecture of pig teat number. The causative variants for teat number may be different in the three population