450 research outputs found

    Observation of Ultrahigh Mobility Surface States in a Topological Crystalline Insulator by Infrared Spectroscopy

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    Topological crystalline insulators (TCIs) possess metallic surface states protected by crystalline symmetry, which are a versatile platform for exploring topological phenomena and potential applications. However, progress in this field has been hindered by the challenge to probe optical and transport properties of the surface states owing to the presence of bulk carriers. Here we report infrared (IR) reflectance measurements of a TCI, (001) oriented Pb1−xSnxSePb_{1-x}Sn_{x}Se in zero and high magnetic fields. We demonstrate that the far-IR conductivity is unexpectedly dominated by the surface states as a result of their unique band structure and the consequent small IR penetration depth. Moreover, our experiments yield a surface mobility of 40000 cm2/(Vs)cm^{2}/(Vs), which is one of the highest reported values in topological materials, suggesting the viability of surface-dominated conduction in thin TCI crystals. These findings pave the way for exploring many exotic transport and optical phenomena and applications predicted for TCIs

    Development of swinging part profilometer for optics

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    A new surface metrology instrument, the ‘Swinging Part Profilometer’ (SPP), has been developed for in-situ measurement of optics undergoing robot-processing in the ground (non-specular) state. In this paper, we present the hardware-design of the SPP, together with software for hardware-control, data-acquisition and surface-reconstruction. First results on a sample part are presented, compared with interferometric metrology, and error-contributions considered. Notably, during each individual scan of a measurement-cycle, the probe remains fixed. This lends itself to automated probe-deployment by the same robot as performs surface-processing, as probe stability is required on only the time-scale for a single scan

    DeepBurning-MixQ: An Open Source Mixed-Precision Neural Network Accelerator Design Framework for FPGAs

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    Mixed-precision neural networks (MPNNs) that enable the use of just enough data width for a deep learning task promise significant advantages of both inference accuracy and computing overhead. FPGAs with fine-grained reconfiguration capability can adapt the processing with distinct data width and models, and hence, can theoretically unleash the potential of MPNNs. Nevertheless, commodity DPUs on FPGAs mostly emphasize generality and have limited support for MPNNs especially the ones with lower data width. In addition, primitive DSPs in FPGAs usually have much larger data width than that is required by MPNNs and haven't been sufficiently co-explored with MPNNs yet. To this end, we propose an open source MPNN accelerator design framework specifically tailored for FPGAs. In this framework, we have a systematic DSP-packing algorithm to pack multiple lower data width MACs in a single primitive DSP and enable efficient implementation of MPNNs. Meanwhile, we take DSP packing efficiency into consideration with MPNN quantization within a unified neural network architecture search (NAS) framework such that it can be aware of the DSP overhead during quantization and optimize the MPNN performance and accuracy concurrently. Finally, we have the optimized MPNN fine-tuned to a fully pipelined neural network accelerator template based on HLS and make best use of available resources for higher performance. Our experiments reveal the resulting accelerators produced by the proposed framework can achieve overwhelming advantages in terms of performance, resource utilization, and inference accuracy for MPNNs when compared with both handcrafted counterparts and prior hardware-aware neural network accelerators on FPGAs.Comment: Accepted by 2023 IEEE/ACM International Conference on Computer-Aided Design (ICCAD

    LncRNA gas5 regulates granulosa cell apoptosis and viability following radiation by x-ray via sponging miR-205- 5p and Wnt/β-catenin signaling pathway in granulosa cell tumor of ovary

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    Purpose: To investigate the role of lncRNA gas5 in ovarian granulosa cells exposed to x-ray in granulosa cell tumor of ovary (GCTO). Methods: KGN cell line was exposed to X-ray to mimic the radiotherapy for GCSO patients in vitro, cell viability was checked by CCK8 assays. RNA expression of apoptosis-related genes was determined by quantitative reverse transcriptase-polymerase reaction (qRT-PCR) while Western Blot for biomarkers in wnt/β-catenin signaling. Differential expressions of lncRNA gas5 were examined after cells were exposed to a ray for 0,24,48hs. We over expressed gas5 and assessed resultant cell viability, apoptosis and signaling. The sponging between gas5 and miR-205-5p was verified by luciferase assay. CCK8, qRT-PCR and Western blot were applied to investigate the correlation between miR-205-5p, cell viability, and apoptosis after miR-205-5p augmentation. Similarly, interaction between gas5 and miR-205-5p was assessed after co-transfection of miR-205-5p mimics and oe-gas5. Finally, wnt inhibitor was used to study the role of signaling pathway in KGN cells. Results: Exposure of KGN to x-ray reduced cell viability and increased apoptosis. Gas5showed reduced expression in the cells, while miR-205-5p  expression increased. Gas5 upregulation protected the cells against apoptosis and contributed to cell viability and activation of wnt//β-catenin signaling. lncRNA gas5 targeted miR-205-5p and miR-205-5p mimics counteracted the functions of up-regulated lncRNA gas5, regulating Wnt/β-catenin signaling pathway. Inactivation of Wnt/β-catenin suppressed cell viability. Conclusions: lncRNA gas5 regulates cell apoptosis and viability following cellular radiation, thus presenting a potential therapeutic target for the application radiotherapy in GCTO patients. Keywords: Ovary, Proliferation, Apoptosis, lncRNA gas5, Radiotherapy, β-catenin signalin

    LncRNA gas5 regulates granulosa cell apoptosis and viability following radiation by X-ray through sponging miR-205-5p and Wnt/β-catenin signaling pathway ingranulosa cell tumor of ovary

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    Purpose: The study explored the role of lncRNA gas5 in ovarian granulosa cells exposed to X-ray in granulosa cell tumor of  ovary(GCTO). Methods:Exposed the KGN cell line (KALANG, Beijing, China) to X-ray to mimic the radiotherapy for GCSO patients in vitro, cell viability was checked by CCK8 assays. RT-qPCR detected the RNA expression of apoptosis-related genes while Western Blot for biomarkers in wnt/β-catenin signaling. Differential expressions of lncRNA gas5 were examined after cells exposed to X ray for 0,24,48hs. We over expressed gas5 and assessed resultant cell viabilities, apoptosis and signaling. The sponging between gas5 and miR-205-5p was verified through Luciferase Assay. CCK8, RT-qPCR and Western Blot were applied for investigations into the correlation between miR-205-5p and cell viability and apoptosis after miR-205-5p augmentation. Similarly, the interactions between the gas5 and  miR-205-5p were assessed after co-transfection of miR-205-5p mimics and oe-gas5. Last, wnt inhibitor was used to study the role of signaling pathway in KGN cells. Results: Exposure of KGN toX-ray reduced cell viabilities and increased apoptosis. Gas5 had reduced expression in cells while  miR-205-5p increased. Gas5 upregulation could protect the cells from apoptosis and add to the cell viability and activation of wnt//β-catenin signaling. lncRNA gas5 targeted miR-205-5p and miR-205-5p mimics could counteract functions of up-regulated lncRNA gas5, regulating Wnt/β-catenin signaling pathway. Inactivation in Wnt/β-catenin could suppress cell viability. Conclusions: lncRNA gas5 regulated the cell apoptosis and viability after cellular radiation, which might be a potential therapeutic target to combine into radiotherapy for GCTO patients in clinical stage. Keywords: Ovary, proliferation, apoptosis, lncRNA gas5, x-ra

    Mass and Heat Balance of a Lake Ice Cover in the Central Asian Arid Climate Zone

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    To improve the understanding of the seasonal evolution of the mass and heat budget of ice-covered lakes in the cold and arid climate zone, in-situ observations were collected during two winters (2016–2017 and 2017–2018) in Lake Wuliangsuhai, Inner Mongolia, China. The mean snow thickness was 5.2 and 1.6 cm in these winters, due to low winter precipitation. The mean ice thickness was 50.9 and 36.1 cm, and the ice growth rate was 3.6 and 2.1 mm day−1 at the lower boundary of ice. Analyses of mass and heat balance data from two winters revealed that the surface heat budget was governed by solar radiation and terrestrial radiation. The net heat flux loss of the ice was 9–22 W m−2, affected by the snow and ice thickness. Compared to boreal lakes, Lake Wuliangsuhai received more solar radiation and heat flux from the water. The ice temperature had a strong diurnal variation, which was produced by the diurnal cycles of solar radiation, and air and water temperatures. These results expand our knowledge of the evolution of mass and heat balance in temperate lakes of mid-latitude arid areas

    Solar radiation transfer for an ice-covered lake in the central Asian arid climate zone

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    Spectral albedo and light transmittance through snow, ice, and water were measured in Lake Wuliangsuhai (40 degrees 36 '-41 degrees 30 ' N, 108 degrees 43 '-108 degrees 70 ' E), Inner Mongolia, China, during winter 2016. Data on the weather, structure of lake ice, and geochemistry of water were also collected during the 60-day field program. The study lake is shallow (mean depth 1.0-1.5 m) with a large wetland area. Compared with polar lakes, solar elevation is higher, snow accumulation is much lower, and the ice has more sediment. The ice was all congelation ice with a mean thickness of 36.6 cm, corresponding to a mean air temperature of -9.6 degrees C. The mean daily broadband albedo and photosynthetically active radiation (PAR) band transmittance were 0.54 and 0.08 (bare ice), 0.74 and 0.04 (new snow), and 0.30 and 0.12 (melting period), respectively. The level of light allowed photosynthesis to occur to the bottom of the lake. The ice acted as a grey filter for the sunlight with a mean attenuation coefficient of 2.1 m(-1). These results expand our knowledge of the evolution of light transfer through ice and snow cover and its role in the ecology of lakes in temperate and arid areas.Peer reviewe

    Development of one-step SYBR Green real-time RT-PCR for quantifying bovine viral diarrhea virus type-1 and its comparison with conventional RT-PCR

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    <p>Abstract</p> <p>Background</p> <p>Bovine viral diarrhea virus (BVDV) is a worldwide pathogen in cattle and acts as a surrogate model for hepatitis C virus (HCV). One-step real-time fluorogenic quantitative reverse transcription polymerase chain reaction (RT-PCR) assay based on SYBR Green I dye has not been established for BVDV detection. This study aims to develop a quantitative one-step RT-PCR assay to detect BVDV type-1 in cell culture.</p> <p>Results</p> <p>One-step quantitative SYBR Green I RT-PCR was developed by amplifying cDNA template from viral RNA and using <it>in vitro </it>transcribed BVDV RNA to establish a standard curve. The assay had a detection limit as low as 100 copies/ml of BVDV RNA, a reaction efficiency of 103.2%, a correlation coefficient (R<sup>2</sup>) of 0.995, and a maximum intra-assay CV of 2.63%. It was 10-fold more sensitive than conventional RT-PCR and can quantitatively detect BVDV RNA levels from 10-fold serial dilutions of titrated viruses containing a titer from 10<sup>-1 </sup>to 10<sup>-5 </sup>TCID<sub>50</sub>, without non-specific amplification. Melting curve analysis showed no primer-dimers and non-specific products.</p> <p>Conclusions</p> <p>The one-step SYBR Green I RT-PCR is specific, sensitive and reproducible for the quantification of BVDV in cell culture. This one-step SYBR Green I RT-PCR strategy may be further optimized as a reliable assay for diagnosing and monitoring BVDV infection in animals. It may also be applied to evaluate candidate agents against HCV using BVDV cell culture model.</p

    Diurnal Cycle Model of Lake Ice Surface Albedo : A Case Study of Wuliangsuhai Lake

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    Ice surface albedo is an important factor in various optical remote sensing technologies used to determine the distribution of snow or melt water on the ice, and to judge the formation or melting of lake ice in winter, especially in cold and arid areas. In this study, field measurements were conducted at Wuliangsuhai Lake, a typical lake in the semi-arid cold area of China, to investigate the diurnal variation of the ice surface albedo. Observations showed that the diurnal variations of the ice surface albedo exhibit bimodal characteristics with peaks occurring after sunrise and before sunset. The curve of ice surface albedo with time is affected by weather conditions. The first peak occurs later on cloudy days compared with sunny days, whereas the second peak appears earlier on cloudy days. Four probability density distribution functions—Laplace, Gauss, Gumbel, and Cauchy—were combined linearly to model the daily variation of the lake ice albedo on a sunny day. The simulations of diurnal variation in the albedo during the period from sunrise to sunset with a solar altitude angle higher than 5° indicate that the Laplace combination is the optimal statistical model. The Laplace combination can not only describe the bimodal characteristic of the diurnal albedo cycle when the solar altitude angle is higher than 5°, but also reflect the U-shaped distribution of the diurnal albedo as the solar altitude angle exceeds 15°. The scale of the model is about half the length of the day, and the position of the two peaks is closely related to the moment of sunrise, which reflects the asymmetry of the two peaks of the ice surface albedo. This study provides a basis for the development of parameterization schemes of diurnal variation of lake ice albedo in semi-arid cold regions

    Development of one-step SYBR Green real-time RT-PCR for quantifying bovine viral diarrhea virus type-1 and its comparison with conventional RT-PCR

    Get PDF
    Background Bovine viral diarrhea virus (BVDV) is a worldwide pathogen in cattle and acts as a surrogate model for hepatitis C virus (HCV). One-step real-time fluorogenic quantitative reverse transcription polymerase chain reaction (RT-PCR) assay based on SYBR Green I dye has not been established for BVDV detection. This study aims to develop a quantitative one-step RT-PCR assay to detect BVDV type-1 in cell culture. Results One-step quantitative SYBR Green I RT-PCR was developed by amplifying cDNA template from viral RNA and using in vitro transcribed BVDV RNA to establish a standard curve. The assay had a detection limit as low as 100 copies/ml of BVDV RNA, a reaction efficiency of 103.2%, a correlation coefficient (R2) of 0.995, and a maximum intra-assay CV of 2.63%. It was 10-fold more sensitive than conventional RT-PCR and can quantitatively detect BVDV RNA levels from 10-fold serial dilutions of titrated viruses containing a titer from 10-1 to 10-5 TCID50, without non-specific amplification. Melting curve analysis showed no primer-dimers and non-specific products. Conclusions The one-step SYBR Green I RT-PCR is specific, sensitive and reproducible for the quantification of BVDV in cell culture. This one-step SYBR Green I RT-PCR strategy may be further optimized as a reliable assay for diagnosing and monitoring BVDV infection in animals. It may also be applied to evaluate candidate agents against HCV using BVDV cell culture model
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