34 research outputs found
Energy-aware 3D micro-machined inductive suspensions with polymer magnetic composite core
This paper addresses the issue of Joule heating in micromachined inductive suspensions (MIS) and reports a significant decrease of the operating temperature by using a polymer magnetic composite (PMC) core. The PMC material has a high resistivity, thus inhibiting the formation of eddy currents, and a high permeability, thus guiding the magnetic field more efficiently within the MIS structure. We experimentally study the distribution of the PMC material inside the MIS structure and evaluate the effect of the core from the dependence of the levitation height on the excitation current. The experiments carried on in ambient room temperature demonstrate that the temperature inside the micromachined inductive suspension is reduced to 58°C, which is a record-low temperature compared to other MIS structures reported before
Hollow microcoils made possible with external support structures manufactured with a two-solvent process
We present a process to manufacture solenoidal microcoils with external support structures, which leaves the space within the coil windings free. The manufacturing procedure is based on a two solvent approach (water and acetone), for selectively etching polyvinyl alcohol and polymethyl methacrylate. Two sets of microcoils were manufactured with an inner diameter of 1.5 mm, an interwinding pitch of 100 μm and five or eight coil windings respectively. The coils were designed for application in magnetic resonance imaging and spectroscopy, and characterised in a 9.4 T MR scanner. An NMR spectrum of water and MR images in receive only and transceive mode were acquired as proof of concept
Heteronuclear micro-helmholtz coil facilitates μm-range spatial and sub-Hz spectral resolution NMR of nL-volume samples on customisable microfluidic chips
We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∗ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, applicationspecific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∗2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2 O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks during assembly, while we exchanged the laser-cut, PMMA spacers by diced glass spacers, which are not susceptible to melting during cutting. Doing so led to an overall simplification of the entire fabrication chain, while simultaneously increasing the yield, due to an improved uniformity of thickness of the individual layers, and in addition, due to more accurate vertical positioning of the wirebonded coils, now delimited by a post base plateau. We demonstrate the capability of the design by acquiring a1 H spectrum of ∗ \11 nmol sucrose dissolved in D2 O, where we achieved a linewidth of 1.25 Hz for the TSP reference peak. Chemical shift imaging experiments were further recorded from voxel volumes of only ∗ 1.5nL, which corresponded to amounts of just 1.5 nmol per voxel for a 1 M concentration. To extend the micro-detector to other nuclei of interest, we have implemented a trap circuit, enabling heteronuclear spectroscopy, demonstrated by two 1H/13 C 2D HSQC experiments. © 2016 Spengler et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Unconventional applications of wire bonding create opportunities for microsystem integration
The effect of eight weeks of aquatic aerobic training on abca1 and abcg1 genes expression in the blood mononuclear cells in women after coronary artery bypass grafting
Background: The aim of this research was to investigate the effect of aquatic aerobic training on regulatory factors related to Reverse Cholesterol Transport in women after coronary artery bypass grafting (CABG). Methods: 24 middle-aged women were studied after coronary artery bypass grafting (12 were in control group and 12 in aquatic aerobic training group). The aquatic aerobic training program was performed in a pool of 1.20 m depth for eight weeks (three sessions per week with 50-75 intensity of the maximum heart rate). Furthermore, 48 hours before initiating the training program as well as 48 hours after the last training session, blood samples were taken in a fasting state. Then, Leukocytes were isolated, total cellular RNAs were extracted and complementary DNAs were synthesized. Gene expressions of ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette sub-family G member 1 (ABCG1) were evaluated at messenger RNA levels using real-time PCR method. The amounts of ApolipoproteinA-1(Apo A-1), high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL) were measured in plasma using an enzyme-linked immune sorbent assay method. Statistical analysis was performed using an independent-sample t-test and covariance, with a significance level accepted at P<0.05. Results: The findings showed that aquatic training was able to express ABCA1 and ABCG1 gene in women after coronary artery bypass grafting. The data pointed to the possibility that aquatic training during the cardiac rehabilitation period can improve the reverse cholesterol transport and can be an alternative exercise program to achieve physical preparation and rehabilitation objectives in individuals who may have trouble doing exercises on the ground. © 2020, Kerman University of Medical Sciences. All rights reserved
Effect of dietary inorganic copper on growth performance and some hematological indices of Siberian Sturgeon Acipenser baerii juveniles
This research work was conducted to evaluate the effect of dietary copper (Cu) levels on growth performance, feed utilization, and some hematological parameters of juvenile Siberian Sturgeon Acipenser baerii. Five semipurified diets containing 0, 3, 6, 12, and 24 mg Cu/kg in the form of copper sulfate pentahydrate (CuSO4·5H2O) were formulated to provide the actual dietary copper values of 1.8, 5.7, 10.1, 15.9, and 28.3 mg Cu/kg diet, respectively. The obtained results exhibited a significant improvement in the final weight, protein efficiency ratio, daily growth coefficient, and hepatosomatic index with increasing dietary copper levels up to 10.1 mg/kg diet, while the feed conversion ratio significantly decreased. Also, erythrocyte count, hemoglobin, and hematocrit values increased with increasing levels of dietary copper, but no steady trend was observed in mean corpuscular hemoglobin changes. Furthermore, the neutrophils were significantly increased with enhancing the copper level in the fish diet, while the lymphocytes declined. Findings of the current research illustrate that an appropriate dietary copper level is required for improvement of growth performance, oxygen transfer capability, and white blood cell proliferation. Based on the broken‐line regression analysis of leukocyte count and monocyte percentage, the optimum dietary copper supplementation was estimated to be 10.63 and 10.36 mg Cu/kg diet, respectively
Hollow microcoils made possible with external support structures manufactured with a two-solvent process
We present a process to manufacture solenoidal microcoils with external support structures, which leaves the space within the coil windings free. The manufacturing procedure is based on a two solvent approach (water and acetone), for selectively etching polyvinyl alcohol and polymethyl methacrylate. Two sets of microcoils were manufactured with an inner diameter of 1.5 mm, an interwinding pitch of 100 μm and five or eight coil windings respectively. The coils were designed for application in magnetic resonance imaging and spectroscopy, and characterised in a 9.4 T MR scanner. An NMR spectrum of water and MR images in receive only and transceive mode were acquired as proof of concept
Comment on “Comparison of the Ability of ARIMA, WNN and SVM Models for Drought Forecasting in the Sanjiang Plain, China” by Yuhu Zhang, Huirong Yang, Hengjian Cui, and Qiuhua Chen, in Natural Resources Research DOI: 10.1007/s11053-019-09512-6
Energy-aware 3D micro-machined inductive suspensions with polymer magnetic composite core
Coronary Artery Disease Risk Factors in an Urban and Peri-urban Setting, Kerman, Southeastern Iran (KERCADR Study): Methodology and Preliminary Report
Background: This article was to present the sampling and measurements methods and the main preliminary findings of the KERCADR cohort study (first round) in an urban and peri-urban setting, Kerman, southeastern Iran2009-11. Method: 5900 (3238 female) people aged between 15 to 75 years were recruited in the household survey by non-proportional to size one-stage cluster sampling. Trained internal specialists, general practitioners, clinical psychologists and dentists have assessed the study subjects by person-assisted questionnaires regarding different NCD risk factors including cigarette and opium smoking, physical activity, nutrition habits, anxiety, depression, obesity, hypertension and oral health. Blood samples were also collected for determining FBS, HbA1c, cholesterol and triglyceride. Weighted standardized prevalence estimates were calculated by STATA 10 survey analysis package. Results: The participation rate was more than 95% in all subgroups. Cigarette smoking (18.4% vs. 1.2%), opium use (17.8% vs. 3.0%) and triglyceridemia (16.1% vs. 12.0%) were significantly higher among men than women. In contrast, women were presented with higher level of sever anxiety (29.1% vs. 16.7%), obesity (16.8% vs. 9.2%), low-physical activity (45.1% vs. 39.2%) and uncontrolled diabetes (60.2% vs. 31.0%). More than 68% of all subjects have presented with moderate to severe gingival index scores. Conclusion: The first round of the KERCADR cohort with sufficient sample size and response rate provided precise estimates for the main clinical and para-clinical NCD risk factors. These evidences need to be translated into public health interventions and monitored in the next rounds of the cohort