59 research outputs found

    Beta-Ga2O3 MOSFETs with near 50 GHz fMAX and 5.4 MV/cm average breakdown field

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    This letter reports high-performance $\mathrm{\beta} Ga2O3 thin channel MOSFETs with T-gate and degenerately doped source/drain contacts regrown by MOCVD. Gate length scaling (LG= 160-200 nm) leads to a peak drain current (ID,MAX) of 285 mA/mm and peak trans-conductance (gm) of 52 mS/mm at 10 V drain bias with 23.5 Ohm mm on resistance (Ron). A low metal/n+ contact resistance of 0.078 Ohm mm was extracted from TLM measurement. Ron is dominated by interface resistance between channel and regrown layer. A gate-to-drain breakdown voltage of 192 V is measured for LGD = 355 nm resulting in average breakdown field (E_AVG) of 5.4 MV/cm. This E_AVG is the highest reported among all sub-micron gate length lateral FETs. RF measurements on 200 nm Silicon Nitride (Si3N4) passivated device shows a current gain cut off frequency (f_T) of 11 GHz and record power gain cut off frequency (f_MAX) of 48 GHz. The f_T.V_Br product is 2.11 THz.V for 192 V breakdown voltage. The switching figure of merit exceeds that of silicon and is comparable to mature wide-band gap devices

    Diagnostic efficacy of metagenomic next generation sequencing in bronchoalveolar lavage fluid for proven invasive pulmonary aspergillosis

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    ObjectiveTo assess the diagnostic efficacy of metagenomic next generation sequencing (mNGS) for proven invasive pulmonary aspergillosis (IPA).MethodsA total of 190 patients including 53 patients who had been diagnosed with proven IPA were retrospectively analyzed. Using the pathological results of tissue biopsy specimens as gold standard, we ploted the receiver operating characteristic (ROC) curve to determine the optimal cut-off value of mNGS species-specific read number (SSRN) of Aspergillus in bronchoalveolar lavage fluid (BALF)for IPA. Furthermore, we evaluated optimal cut-off value of mNGS SSRN in different populations.ResultsThe optimal cut-off value of Aspergillus mNGS SSRN in BALF for IPA diagnosis was 2.5 for the whole suspected IPA population, and 1 and 4.5 for immunocompromised and diabetic patients, respectively. The accuracy of mNGS was 80.5%, 73.7% and 85.3% for the whole population, immunocompromised and diabetic patients, respectively.ConclusionsThe mNGS in BALF has a high diagnostic efficacy for proven IPA, superioring to Aspergillus culture in sputum and BALF and GM test in blood and BALF. However, the cut-off value of SSRN should be adjusted when in different population

    A triton X-100 assisted PMAxx-qPCR assay for rapid assessment of infectious African swine fever virus

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    IntroductionAfrican Swine Fever (ASF) is a highly infectious disease of pigs, caused by African swine fever virus (ASFV). The lack of vaccines and drugs makes strict disinfection practices to be one of the main measurements to curb the transmission of ASF. Therefore, it is important to assess if all viruses are inactivated after disinfection or after long time exposure in their natural conditions. Currently, the infectivity of ASFV is determined by virus isolation and culture in a biosafety level 3 (BSL-3) laboratory. However, BSL-3 laboratories are not readily available, need skilled expertise and may be time consuming.MethodsIn this study, a Triton X-100 assisted PMAxx-qPCR method was developed for rapid assessment of infectious ASFV in samples. PMAxx, an improved version of propidium monoazide (PMA), can covalently cross-link with naked ASFV-DNA or DNA inside inactivated ASFV virions under assistance of 0.1% (v/v) TritonX-100, but not with ASFV-DNA inside live virions. Formation of PMAxx-DNA conjugates prevents PCR amplification, leaving only infectious virions to be detected. Under optimum conditions, the limit of detection of the PMAxx-qPCR assay was 2.32log10HAD50/mL of infectious ASFV. Testing different samples showed that the PMAxx-qPCR assay was effective to evaluate intact ASFV virions after treatment by heat or chemical disinfectants and in simulated samples such as swine tissue homogenate, swine saliva swabs, and environmental swabs. However, whole-blood and saliva need to be diluted before testing because they may inhibit the PCR reaction or the cross-linking of PMAxx with DNA.ConclusionThe Triton X-100 assisted PMAxx-qPCR assay took less than 3 h from sample to result, offering an easier and faster way for assessing infectious ASFV in samples from places like pig farms and pork markets

    [68Ga]Ga-DOTA-FAPI-04 PET/MR in patients with acute myocardial infarction: potential role of predicting left ventricular remodeling.

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    PURPOSE To assess predictive value of 68Ga-labeled fibroblast activation protein inhibitor-04 ([68Ga]Ga-DOTA-FAPI-04) PET/MR for late left ventricular (LV) remodeling in patients with ST-segment elevated myocardial infarction (STEMI). METHODS Twenty-six patients with STEMI were included in the study. [68Ga]Ga-DOTA-FAPI-04 PET/MR was performed at baseline and at average 12 months after STEMI. LV remodeling was defined as >10% increase in LV end-systolic volume (LVESV) from baseline to 12 months. RESULTS The LV remodeling group demonstrated higher [68Ga]Ga-DOTA-FAPI-04 uptake volume (UV) at baseline than the non-LV remodeling group (p < 0.001). [68Ga]Ga-DOTA-FAPI-04 UV at baseline was a significant predictor (OR = 1.048, p = 0.011) for LV remodeling at 12 months after STEMI. Compared to clinical information, MR imaging and cardiac function parameters at baseline, [68Ga]Ga-DOTA-FAPI-04 UV demonstrated better predictive ability (AUC = 0.938, p < 0.001) for late LV remodeling, with sensitivity of 100.0% and specificity of 81.3%. CONCLUSIONS [68Ga]Ga-DOTA-FAPI-04 PET/MR is an effective tool to non-invasively quantify myocardial fibroblasts activation, and baseline [68Ga]Ga-DOTA-FAPI-04 UV may have potential predictive value for late LV remodeling

    A cross-scanner and cross-tracer deep learning method for the recovery of standard-dose imaging quality from low-dose PET

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    PURPOSE: A critical bottleneck for the credibility of artificial intelligence (AI) is replicating the results in the diversity of clinical practice. We aimed to develop an AI that can be independently applied to recover high-quality imaging from low-dose scans on different scanners and tracers. METHODS: Brain [(18)F]FDG PET imaging of 237 patients scanned with one scanner was used for the development of AI technology. The developed algorithm was then tested on [(18)F]FDG PET images of 45 patients scanned with three different scanners, [(18)F]FET PET images of 18 patients scanned with two different scanners, as well as [(18)F]Florbetapir images of 10 patients. A conditional generative adversarial network (GAN) was customized for cross-scanner and cross-tracer optimization. Three nuclear medicine physicians independently assessed the utility of the results in a clinical setting. RESULTS: The improvement achieved by AI recovery significantly correlated with the baseline image quality indicated by structural similarity index measurement (SSIM) (r = −0.71, p < 0.05) and normalized dose acquisition (r = −0.60, p < 0.05). Our cross-scanner and cross-tracer AI methodology showed utility based on both physical and clinical image assessment (p < 0.05). CONCLUSION: The deep learning development for extensible application on unknown scanners and tracers may improve the trustworthiness and clinical acceptability of AI-based dose reduction. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00259-021-05644-1

    Temperature-Dependent Structure and Dynamics of Water Intercalated in Layered Double Hydroxides with Different Hydration States

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    Properties of water confined in layered double hydroxides (LDH) are relevant with hydration, dehydration, and protonic conduction in interlayer galleries. Evolutions of structure and dynamics of water in LDHs (Mg2Al(OH)(6)Cl center dot mH(2)O) with temperature are disclosed through molecular dynamics simulations performed in the range from 300 to 430 K. LDHs with m = 0.78 and 1.44 which characterize two different hydration states are investigated. Water in the lower hydration state is characterized with higher ordered structure. Irrespective of water content, water becomes less hydrogen bonded and more disordered as temperature increases. This leads to a large decrement in dehydration enthalpy, which facilitates dehydration energetically. Irrespective of temperature or water content, water exhibits the preference for being fixed in hydroxyl sites and it diffuses through jumping between neighbor sites. Jump diffusion approximately exhibits an Arrhenius dependence on temperature. A jump is a collective process consisting of water translation and hydroxyl group reorientation, which is reflected in the high activation energy and low attempt frequency. Hydronium ions may be transported through jumping between neighbor sites, making a contribution to proton transfer in interlayer galleries

    A dynamic, architectural plant model simulating resource-dependent growth

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    Accès sur le site éditeur : http://aob.oxfordjournals.org/cgi/content/abstract/93/5/591Background and Aims Physiological and architectural plant models have originally been developed for different purposes and therefore have little in common, thus making combined applications dif®cult. There is, however, an increasing demand for crop models that simulate the genetic and resource-dependent variability of plant geometry and architecture, because man is increasingly able to transform plant production systems through combined genetic and environmental engineering. d Model GREENLAB is presented, a mathematical plant model that simulates interactions between plant structure and function. Dual-scale automaton is used to simulate plant organogenesis from germination to maturity on the basis of organogenetic growth cycles that have constant thermal time. Plant fresh biomass production is computed from transpiration, assuming transpiration ef®ciency to be constant and atmospheric demand to be the driving force, under non-limiting water supply. The fresh biomass is then distributed among expanding organs according to their relative demand. Demand for organ growth is estimated from allometric relationships (e.g. leaf surface to weight ratios) and kinetics of potential growth rate for each organ type. These are obtained through parameter optimization against empirical, morphological data sets by running the model in inverted mode. Potential growth rates are then used as estimates of relative sink strength in the model. These and other `hidden' plant parameters are calibrated using the non-linear, least-square method. d Key Results and Conclusions The model reproduced accurately the dynamics of plant growth, architecture and geometry of various annual and woody plants, enabling 3D visualization. It was also able to simulate the variability of leaf size on the plant and compensatory growth following pruning, as a result of internal competition for resources. The potential of the model's underlying concepts to predict the plant's phenotypic plasticity is discussed
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