| 91. |
- Huang, Yu-Kai, et al.
(författare)
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Noise Analysis of Current-Feedback DC-Servo Loop in Current-Balancing Chopper Amplifiers
- 2022
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Ingår i: 2022 IEEE NORDIC CIRCUITS AND SYSTEMS CONFERENCE (NORCAS). - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Chopper amplifiers for biopotential acquisition commonly suppress differential electrode DC offsets by using a DC-servo loop (DSL). However, the noise contribution of the DSL is always neglected in noise analysis. The noise introduced by the DSL, in particular at low frequencies, is of great importance in biosensor applications. This work presents the noise modeling of a current-balancing chopper amplifier with DSL and describes the effect of the DSL on the noise performance. Two different DSL implementations are analyzed. It is found that the exact placement of the chopper in the DSL has a strong impact in the noise performance; therefore, its placement can not be arbitrarily selected. A circuit topology to minimize its noise contribution is then proposed and verified by simulation.
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| 92. |
- Huang, Ya-Yao, et al.
(författare)
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A two‐center study for the quality control of [18F]FDG using FASTlab phosphate cassettes
- 2016
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Ingår i: Annals of Nuclear Medicine. - : Springer. - 0914-7187 .- 1864-6433. ; 30:8, s. 563-571
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The GE FASTlab radiosynthesis module is routinely used for the production of [18F]FDG, utilizing the commercially available phosphate cassettes. Because of the observation of a white precipitate in the product vial before the product expiry time, we re-examined the quality of the produced [18F]FDG solution.Methods: Phosphate buffered [18F]FDG solution was synthesized on the FASTlab and analyzed at both National Taiwan University Hospital (NTUH) of Taiwan and Royal Brisbane and Women’s Hospital (RBWH) of Australia. In addition to the standard product quality control (QC), the concentration of aluminum (Al3+) as probable cause of the precipitations in the [18F]FDG solution was analyzed by inductively coupled plasma mass spectrometry (ICP-MS at RBWH) and inductively coupled plasma optical emission spectrometry (ICP-OES at NTUH), and using three semi-quantitative methods at NTUH, Advantec® Alumi Check Test Strip, Quantofix® Aluminum Test Strip and MColortest™ Aluminum Test kit.Results: The precipitates were observed in the [18F]FDG solution within 24 (NTUH) and 6 (RBWH) hours after the end of synthesis in 38–100 % of the batches, dependent on the batch of the FASTlab cassettes. Addition of metal-free HCl(aq) to aliquots of [18F]FDG containing precipitate, followed by ICP-MS analysis revealed Al3+ concentrations of 70–80 ppm. Al3+ concentrations of 10–12 ppm were detected in [18F]FDG batches that did not show any precipitation. In contrast, less than 5 ppm of the residual Al3+ was detected by semi-quantitative methods in all batches.Conclusion: The US (USP), British (BP), European (EP) and Japanese (JP) pharmacopeias demand that [18F]FDG for injection should be clear and particulate free within the given shelf-life/expiration time. To avoid Al-phosphate precipitation within the product expiry time, FASTlab citrate cassettes, rather than phosphate cassettes, should be used for [18F]FDG production. Although testing for Al3+ is not listed in the [18F]FDG monographs of the USP, BP and EP, residual Al3+ levels should be considered in the interests of patient safety.
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| 93. |
- Jacobs, Eric J, et al.
(författare)
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Family history of cancer and risk of pancreatic cancer : A pooled analysis from the Pancreatic Cancer Cohort Consortium (PanScan).
- 2010
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215.
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Tidskriftsartikel (refereegranskat)abstract
- A family history of pancreatic cancer has consistently been associated with increased risk of pancreatic cancer. However, uncertainty remains about the strength of this association. Results from previous studies suggest a family history of select cancers (i.e., ovarian, breast and colorectal) could also be associated, although not as strongly, with increased risk of pancreatic cancer. We examined the association between a family history of 5 types of cancer (pancreas, prostate, ovarian, breast and colorectal) and risk of pancreatic cancer using data from a collaborative nested case-control study conducted by the Pancreatic Cancer Cohort Consortium. Cases and controls were from cohort studies from the United States, Europe and China, and a case-control study from the Mayo Clinic. Analyses of family history of pancreatic cancer included 1,183 cases and 1,205 controls. A family history of pancreatic cancer in a parent, sibling or child was associated with increased risk of pancreatic cancer [multivariate-adjusted odds ratios (ORs) = 1.76, 95% confidence interval (CI) = 1.19-2.61]. A family history of prostate cancer was also associated with increased risk (OR = 1.45, 95% CI = 1.12-1.89). There were no statistically significant associations with a family history of ovarian cancer (OR = 0.82, 95% CI = 0.52-1.31), breast cancer (OR = 1.21, 95% CI = 0.97-1.51) or colorectal cancer (OR = 1.17, 95% CI = 0.93-1.47). Our results confirm a moderate sized association between a family history of pancreatic cancer and risk of pancreatic cancer and also provide evidence for an association with a family history of prostate cancer worth further study.
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| 94. |
- Jia, Kai-Hua, et al.
(författare)
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Chromosome-scale assembly and evolution of the tetraploid Salvia splendens (Lamiaceae) genome
- 2021
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Ingår i: Horticulture Research. - : Oxford University Press (OUP). - 2052-7276 .- 2662-6810. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Polyploidization plays a key role in plant evolution, but the forces driving the fate of homoeologs in polyploid genomes, i.e., paralogs resulting from a whole-genome duplication (WGD) event, remain to be elucidated. Here, we present a chromosome-scale genome assembly of tetraploid scarlet sage (Salvia splendens), one of the most diverse ornamental plants. We found evidence for three WGD events following an older WGD event shared by most eudicots (the γ event). A comprehensive, spatiotemporal, genome-wide analysis of homoeologs from the most recent WGD unveiled expression asymmetries, which could be associated with genomic rearrangements, transposable element proximity discrepancies, coding sequence variation, selection pressure, and transcription factor binding site differences. The observed differences between homoeologs may reflect the first step toward sub- and/or neofunctionalization. This assembly provides a powerful tool for understanding WGD and gene and genome evolution and is useful in developing functional genomics and genetic engineering strategies for scarlet sage and other Lamiaceae species.
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| 95. |
- Khodorkovskii, M. A., et al.
(författare)
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Multiphoton mass spectra of XeKr molecules in the range of excited Xe*6p[5/2](2,3) atoms
- 2007
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Ingår i: Optics and Spectroscopy. - 0030-400X .- 1562-6911. ; 102:6, s. 834-841
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Tidskriftsartikel (refereegranskat)abstract
- Data on excited states of XeKr molecules in the energy range 78280-77600 cm(-1) are obtained. Using the method of multiphoton laser photoionization of molecules in a supersonic jet, five vibrational progressions of XeKr molecules are obtained, which are attributed to five electronic-vibrational transitions from the ground state of the XeKr molecule of the symmetry 0(+) to excited states of the symmetry Omega = 0(+), 1, 2 with the dissociation limit (KrS0)-S-1 + Xe*6p[5/2](2) and of the symmetry Omega = 1, 2 with the dissociation limit Kr + Xe*6p[5/2](3). The molecular constants of the corresponding excited states of the XeKr molecule are estimated.
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| 96. |
- Kirchhoff, Tomas, et al.
(författare)
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Breast cancer risk and 6q22.33 : combined results from Breast Cancer Association Consortium and Consortium of Investigators on Modifiers of BRCA1/2
- 2012
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Ingår i: PLOS ONE. - : Public library of science. - 1932-6203. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Recently, a locus on chromosome 6q22.33 (rs2180341) was reported to be associated with increased breast cancer risk in the Ashkenazi Jewish (AJ) population, and this association was also observed in populations of non-AJ European ancestry. In the present study, we performed a large replication analysis of rs2180341 using data from 31,428 invasive breast cancer cases and 34,700 controls collected from 25 studies in the Breast Cancer Association Consortium (BCAC). In addition, we evaluated whether rs2180341 modifies breast cancer risk in 3,361 BRCA1 and 2,020 BRCA2 carriers from 11 centers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Based on the BCAC data from women of European ancestry, we found evidence for a weak association with breast cancer risk for rs2180341 (per-allele odds ratio (OR) = 1.03, 95% CI 1.00-1.06, p = 0.023). There was evidence for heterogeneity in the ORs among studies (I(2) = 49.3%; p = <0.004). In CIMBA, we observed an inverse association with the minor allele of rs2180341 and breast cancer risk in BRCA1 mutation carriers (per-allele OR = 0.89, 95%CI 0.80-1.00, p = 0.048), indicating a potential protective effect of this allele. These data suggest that that 6q22.33 confers a weak effect on breast cancer risk.
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| 97. |
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| 98. |
- Li, Kai, et al.
(författare)
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Metal thermopile infrared detector with vertical graphene
- 2023
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Ingår i: Wuli Xuebao/Acta Physica Sinica. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 72:3
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Tidskriftsartikel (refereegranskat)abstract
- Thermopile infrared detector is a kind of detector device mainly composed of thermocouple as the basic unit. Because of its simple principle, no need of cooling equipment, and other advantages, it has been widely used in various fields of production and life. However, the absorption rates of the materials in conventional thermopile devices are poor, and the majority of them are incompatible with microfabrication methods. In this work, a metal thermopile infrared detector with vertical graphene (VG) is designed and fabricated. The VG is grown via plasma enhanced chemical vapor deposition, and retained at the device’s thermal ends to provide the thermopile IR detector’s wideband and high response characteristics. The detector achieves a room temperature responsivity reaching a value as high as 1.53 V/W at 792 nm, which can increase the response results about 28 times and reduce the response time to 0.8 ms compared with the thermopile detector without VG. After systematically measuring the response results, it is finally found that there are three main mechanisms responsible for the response on the composite device. The first one is the response generated by the metal thermopile itself alone. The second one is the response increased eventually by the contribution of VG covered at the metal thermal junction that expands the temperature difference. The last one is the response generated by the temperature gradient existing inside the VG on the surface of the device after the absorption of heat. The portion of each partial response mechanism in the total response is also analyzed, providing a new reference direction for analyzing the response generation mechanism of thermopile detectors with other absorbing materials. The process is compatible with the microfabrication, while the device performance is enhanced and suitable for mass production. Furthermore, by utilizing the surface plasmon resonance to combine VG with metal nanoparticles, the material’ s light absorption is found to be enhanced significantly under the same conditions, and the resulting thermal voltage can be increased to 6 times. The results indicate that VG promises to possess practical applications, in many fields such as photoelectric sensing and power production devices. This technology provides a new method to manufacture high-performance thermopile infrared detectors and other sensor devices.
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| 99. |
- Litjens, Remco, et al.
(författare)
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System-level Assessment of Non-Orthogonal Spectrum Sharing via Transmit Beamforming
- 2013
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Ingår i: Proceedings of the 77th IEEE Vehicular Technology Conference (VTC-spring). - 9781467363372 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- We assess the system-level performance of non-orthogonal spectrum sharing achieved via maximum sum-rate (SR), Nash bargaining (NB), and zero-forcing (ZF) transmit beamforming techniques. A look-up table based physical layer abstraction and radio resource management mechanisms (including packet scheduling) are proposed and incorporated in system-level simulations, jointly with other important aspects of network operation. In the simulated scenarios, the results show similar system-level performance of SR (or NB) as ZF in the context of spectrum sharing, when combined with maximum sum-rate (or proportional fair) packet scheduler. Further sensitivity analysis also shows similar behavior of all three beamforming techniques with regard to the impact on system-level performance of neighbor-cell activity level and feedback error. A more important observation from our results is that, under ideal conditions, the performance enhancement of non-orthogonal spectrum sharing over orthogonal spectrum sharing and fixed spectrum assignment is significant.
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| 100. |
- Liu, Lijun, et al.
(författare)
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Simulating two-phase flow and geomechanical deformation in fractured karst reservoirs based on a coupled hydro-mechanical model
- 2021
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - : Elsevier BV. - 1365-1609 .- 1873-4545. ; 137
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Tidskriftsartikel (refereegranskat)abstract
- Two-phase flow in fractured and karstified porous media subject to coupled hydro-mechanical conditions is an important issue for oil recovery in carbonate reservoirs. However, due to the co-existence of porous media flow, fracture flow and free flow, as well as their couplings with geomechanical deformation, modeling the behavior of fractured karst systems remains challenging. In this work, a novel coupled hydro-mechanical model for simulating the complex behavior of fractured and karstified porous media is developed. Two-phase Darcy's equation is used to describe fluid flow in both matrix and fractures, while the free flow in cavities is considered based on an assumption of phase instantaneous gravity segregation. A modified Barton-Bandis's constitutive model is used to mimic the nonlinear fracture deformation. The cavity deformation is solved based on the fluid pressure on the cavity boundaries. A mixed finite volume-finite element method and a fixed-stress iterative splitting method are adopted to numerically solve the coupled system of equations. The model is then applied to a series of 2D and 3D problems to unravel the impacts of fractures and cavities on two-phase flow and geomechanical deformation in fractured karst systems. The results indicate that cavities hinder water breakthrough due to storage effects, while water may quickly migrate through highly conductive fractures. Cavities tend to dominate the flow and mechanical processes even though fractures are present as well. Significant stress concentration is observed around cavities. Furthermore, the results of 3D cases imply that phase gravity segregation in cavities leads to lower water saturation in the area above cavities and delays water breakthrough.
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