Energy autonomous wireless sensing system enabled by energy generated during human walking

This is the final version of the article. Available from the publisher via the DOI in this record.PowerMEMS 2016,December 6 – 9, 2016. The 16th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, Paris, FranceRecently, there has been a huge amount of work devoted to wearable energy harvesting (WEH) in a bid to establish energy autonomous wireless sensing systems for a range of health monitoring applications. However, limited work has been performed to implement and test such systems in real-world settings. This paper reports the development and real-world characterisation of a magnetically plucked wearable knee-joint energy harvester (Mag-WKEH) powered wireless sensing system, which integrates our latest research progresses in WEH, power conditioning and wireless sensing to achieve high energy efficiency. Experimental results demonstrate that with walking speeds of 3~7 km/h, the Mag-WKEH generates average power of 1.9~4.5 mW with unnoticeable impact on the wearer and is able to power the wireless sensor node (WSN) with three sensors to work at duty cycles of 6.6%~13%. In each active period of 2 s, the WSN is able to measure and transmit 482 readings to the base stationThe authors gratefully acknowledge the financial support from the EPSRC through project EP/K017950/2

Magnetic field energy harvesting from current-carrying structures: electromagnetic-circuit coupled model, validation and application

This is the final version. Available on open access from IEEE via the DOI in this record. Magnetic field energy harvesters (MFEHs) from current-carrying structures/conductors are usually modelled as decoupled electromagnetic and electrical systems. The current-carrying structures may affect the performance of MFEH through the generation of the eddy current and the alteration of the magnetic reluctance. Moreover, the load circuit affects the current generated in the coil and therefore the flux density and eddy current generated. The effects of the current-carrying structure and the load circuit cannot be fully described by the decoupled models. This work develops a finite element model (FEM) that fully couples the electromagnetic and electrical systems by simulating both the magnetic field and eddy current distribution of an MFEH connected to an electrical circuit. The FEM first simulates the coil inductance and resistance of a magnetic field energy harvester (MFEH) placed close to a current-carrying structure exemplified by a rail track. The FEM then simulates the outputs of the MFEH connected to an electrical circuit consisting of a compensating capacitor and optimal load resistor determined by the first step. An MFEH was fabricated and tested under a section of current-carrying rail track. Both experiment and simulation show an increase of both coil resistance and inductance when the MFEH is placed close to the rail track. The good agreement between experimental and simulation results validates that the FEM can predict the full-matrix performances of the MFEH, including the coil parameters, power output and magnetic flux density under the influence of the current-carrying structure and the load circuit. Simulation results reveal that in addition to the permeability of the magnetic core, the electrical conductivity and magnetic permeability of the current-carrying structure considerably affect the performance of the MFEH, which cannot be predicted by decoupled models.Engineering and Physical Sciences Research Council (EPSRC)Royal Societ

Strongly coupled piezoelectric energy harvesters: Optimised design with over 100 mW power, high durability and robustness for self-powered condition monitoring

This is the final version. Available from Elsevier via the DOI in this record.Harvesting ambient vibration energy is a promising method to realise self-powered wireless sensors. However, most of the energy harvesters developed to date are not suitable for real-world applications because of low power output and/or poor durability and robustness. To overcome these challenges, this work develops a strongly coupled piezoelectric stack energy harvester (PSEH) with design considerations not just on the power output but also on the durability and robustness. The PSEH took advantages of the force amplification capability of an optimised mechanical transformer and the high coupling coefficient of a 33-mode multilayer piezoelectric stack to achieve strong coupling and therefore high-power generation. To increase the durability, the piezoelectric stack was pre-compressed to prevent the development of tensile stress, to exploit the high compressive strength of piezoelectric ceramics; the maximum dynamic stress in the mechanical transformer was kept below half of the material’s fatigue limit. Plate springs were used to guide the motion of the PSEH and prevent undesired vibration to enhance robustness. A finite element model was developed for design optimisation, which links the design parameters directly to the full performance matrix including maximum power generation. When actuated at 0.5 g, 157 Hz in the lab tests, the PSEH produced a maximum average power of 140 mW with a 1-mW-bandwidth of 72 Hz and 10-mW-bandwidth of 24 Hz. The PSEH showed no performance degradation after continuously actuated at 0.3 g, 157 Hz for 7.9 h. In addition to the lab tests, on-site tests were performed by installing the PSEH in two locations of a screw air compressor. On-site tests showed that the PSEH was able to produce average power of 15.95 ± 2.3 mW and 43.19 ± 1.52 mW when the acceleration produced by the air compressor was 0.125 ± 0.012 g and 0.259 ± 0.004 g, respectively.Engineering and Physical Sciences Research Council (EPSRC)Royal Societ

Magnetic field energy harvesting from the traction return current in rail tracks

This is the final version. Available from Elsevier via the DOI in this record. Alternating magnetic fields generated by AC traction return currents in rail tracks are an untapped energy source that can be scavenged by a magnetic field energy harvester (MFEH) to power wireless condition monitoring sensors. This paper reports the first comprehensive study on the design, optimisation and experimental testing of such MFEH. The magnetic core has been specially designed with two flux collectors partially enclosing the rail track to increase the power output. An electromagnetic-circuit coupled finite element model (FEM) has been developed to optimise the design under the influence of eddy current loss in the rail track, which has not been investigated before. The simulation reveals that an optimal design should trade off the effective permeability against the eddy current loss, instead of purely maximising the effective permeability as in previous studies. The effects of the various design parameters on the performance of the MFEH have been investigated to obtain an optimised design. An optimised design has been prototyped and tested under a section of current-carrying rail track. The experimental results showed good agreements with simulations. Experimental results show that nonlinear magnetization and magnetic saturation has negatively affected the power generation but the effect can be minimised by increasing the load resistance. The MFEH has produced average power of 5.05, 3.5 and 1.6 W, when placed at 48, 95, 190 mm from the rail track carrying 520 A at 50 Hz, respectively. The power generated has a significant potential for powering wireless sensors for a range of railway monitoring applications.Engineering and Physical Sciences Research Council (EPSRC

A study on the mutagenic effect of dichloromethane extract of pickled vegetables from high risk area for nasopharyngeal carcinoma (NPC)-in Sihui County

The mutagenic effect of dichloromethane extract of pickles collected from Sinhui County was examined. Sample I markedly increased the frequency of sister chromatid exchange (SCE) and the rate of micronucleus (MN) in mice. Sample II also induced an increase in SCE frequency significantly, but the increase in MN rate was slight. Chemical analyses showed that two samples of pickles contained 37.83ppb and 33.38ppb of volatile nitrosamines, respectively, which alone could not explain the observed mutagenic effect. These results sug ested that the pickled vegetables taken from NPC high-risk area, Sihui County, may contain some mutagen(s) besides volatile nitrosamines. 本文報告四會縣醃菜二氯甲烷提取液的誘變性試驗。醃菜樣本提取液Ⅰ號引起姐妹染色單體交換(SCE)率及微核(MN)率顯著升高,醃菜樣本提取液Ⅱ號亦引起SCE率明顯升高,但MN率僅略有升高。化學分析表明,該兩份醃菜的揮發性亞硝胺含量分別為37.83、33.38 ppb。醃菜提取液的誘變性似不能單用亞硝胺來解釋。實驗結果提示,鼻咽癌高發區四會縣醃菜中可能含有除揮發性亞硝胺以外的其他誘變性物質

Somatic Mutagenesis with a Sleeping Beauty Transposon System Leads to Solid Tumor Formation in Zebrafish

Large-scale sequencing of human cancer genomes and mouse transposon-induced tumors has identified a vast number of genes mutated in different cancers. One of the outstanding challenges in this field is to determine which genes, when mutated, contribute to cellular transformation and tumor progression. To identify new and conserved genes that drive tumorigenesis we have developed a novel cancer model in a distantly related vertebrate species, the zebrafish, Danio rerio. The Sleeping Beauty (SB) T2/Onc transposon system was adapted for somatic mutagenesis in zebrafish. The carp ß-actin promoter was cloned into T2/Onc to create T2/OncZ. Two transgenic zebrafish lines that contain large concatemers of T2/OncZ were isolated by injection of linear DNA into the zebrafish embryo. The T2/OncZ transposons were mobilized throughout the zebrafish genome from the transgene array by injecting SB11 transposase RNA at the 1-cell stage. Alternatively, the T2/OncZ zebrafish were crossed to a transgenic line that constitutively expresses SB11 transposase. T2/OncZ transposon integration sites were cloned by ligation-mediated PCR and sequenced on a Genome Analyzer II. Between 700–6800 unique integration events in individual fish were mapped to the zebrafish genome. The data show that introduction of transposase by transgene expression or RNA injection results in an even distribution of transposon re-integration events across the zebrafish genome. SB11 mRNA injection resulted in neoplasms in 10% of adult fish at ∼10 months of age. T2/OncZ-induced zebrafish tumors contain many mutated genes in common with human and mouse cancer genes. These analyses validate our mutagenesis approach and provide additional support for the involvement of these genes in human cancers. The zebrafish T2/OncZ cancer model will be useful for identifying novel and conserved genetic drivers of human cancers

Energy harvesting powered wireless sensor system technologies

This is the author accepted manuscript.Engineering and Physical Sciences Research Council (EPSRC

Antiangiogenic drugs used with chemotherapy for patients with recurrent ovarian cancer: a meta-analysis

SuYi Yi, LongJia Zeng, Yan Kuang, ZhiJuan Cao, ChengJun Zheng, Yue Zhang, Meng Liao, Lu Yang Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, People’s Republic of China Objective: The value of antiangiogenic inhibitors for patients with recurrent ovarian cancer has not been completely affirmed. Therefore, we aimed to assess the effectiveness and toxicities of various antiangiogenic drugs for the treatment of recurrent ovarian cancer. Methods: In this meta-analysis, we searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials databases for complete randomized controlled trials. The searches were extended to May 15, 2016. The risk of bias of the included studies was evaluated via a Cochrane systematic evaluation, and the statistical analyses were performed using RevMan 5.2 software. Results: In total, we included 8 randomized controlled trials involving 3,211 patients and divided them into 3 groups, vascular endothelial growth factor receptor inhibitors (VEGFRIs), vascular endothelial growth factor (VEGF) inhibitors (bevacizumab), and angiopoietin inhibitors (trebananib). The progression-free survival improved significantly in all the groups being given antiangiogenic drugs (hazard ratio [HR]: 0.55, 95% confidence interval [CI]: 0.45–0.67, I2=0%, P<0.00001 for the VEGFRI group; HR: 0.53, 95% CI: 0.45–0.63, I2=51%, P<0.00001 for the VEGF inhibitor group; HR: 0.67, 95% CI: 0.58–0.77, I2=0%, P<0.00001 for the trebananib group). Overall survival was obviously prolonged in the VEGFRI (HR: 0.76, 95% CI: 0.59–0.97, I2=0%, P=0.03), the VEGF inhibitor (HR: 0.87, 95% CI: 0.77–0.99, I2=0%, P=0.03), and trebananib groups (HR: 0.81, 95% CI: 0.67–0.99, I2=0%, P=0.04). The incidence of grade 3/4 side effects was different among the 3 groups, for example, proteinuria, hypertension, gastrointestinal perforation, and arterial thromboembolism were presented in the VEGF inhibitor group. Increased incidences of fatigue, diarrhea, and hypertension were seen in the VEGFRI group, and the trebananib group had a higher incidence of hypokalemia. Conclusion: This meta-analysis showed that antiangiogenic drugs improved the progression-free survival. The VEGFRI, bevacizumab, and trebananib groups showed increased overall survival. Adding antiangiogenic drugs to chemotherapy treatment resulted in a higher incidence of grade 3/4 side effects, but these were manageable. Keywords: antiangiogenesis, recurrent ovarian cancer, progression-free survival, overall survival, toxicit