The COVID‐19 pandemic has rapidly evolved and changed our way of life in an unprecedented manner. The emergence of COVID‐19 has impacted transplantation worldwide. The impact has not been just ...restricted to issues pertaining to donors or recipients, but also health‐care resource utilization as the intensity of cases in certain jurisdictions exceeds available capacity. Here we provide a personal viewpoint representing different jurisdictions from around the world in order to outline the impact of the current COVID‐19 pandemic on organ transplantation. Based on our collective experience, we discuss mitigation strategies such as donor screening, resource planning, and a staged approach to transplant volume considerations as local resource issues demand. We also discuss issues related to transplant‐related research during the pandemic, the role of transplant infectious diseases, and the influence of transplant societies for education and disseminating current information.
The authors discuss the impact of COVID‐19 on donation and transplantation and provide a global framework for donor screening and management of transplant activity during the pandemic.
Self-heating has emerged as an important performance/reliability challenge for modern MOSFETs. The challenge is further acerbated for III-V transistors, especially when integrated monolithically in a ...3-D platform for applications in ultrafast logic, imagers, etc. A key challenge is the difficulty of heat-dissipation through the ultra-thin channels needed to ensure electrostatic integrity of scaled transistors. In this paper, we demonstrate an innovative use of a heat-dissipating shunt of Ni-InGaAs on InGaAs(111) in the S/D extension region, as well as the use of high-conductivity Mo contact to simultaneously improve electrical and thermal stability and heat dissipation in III-V transistors, such that the peak channel temperature is reduced by as much as 25%-30%. Given the exponential temperature sensitivity of transistor reliability, heat shunts will improve transistor lifetime significantly.
Chiral photonics has emerged as a key technology for future optoelectronics, such as quantum information and encryption, by making use of photonic waves from enantiomeric structures. An inevitable ...challenge for realizing such chiral optoelectronics is the development of near‐infrared circularly polarized (NIR CP) light‐sensing photodetectors that convert optical power and circular polarization direction into distinguishable electrical signals. Herein, a simple and promising strategy for high‐performance NIR CP light‐sensing organic phototransistors (NIR CPL‐OPTRs) applicable to highly secure optoelectronic encryption is proposed. By directly assembling a standalone cholesteric liquid‐crystal network film in a thin‐film NIR CPL‐OPTR, remarkable responsivity and distinguishability are achieved. The synergetic effect of amplification of the photocurrent signal by the applied electric field and improved light absorption by the reduced reflection in the multilayered structure leads to high responsivity. As a proof‐of‐concept, the chiral phototransistor arrays are demonstrated as a physically unclonable function device and exhibit enhanced cryptographic characteristics.
High‐performance near‐infrared circularly polarized light‐sensing organic phototransistors are realized by directly assembling a standalone cholesteric liquid‐crystal network film in the near‐infrared‐sensing organic phototransistor based on a small‐bandgap polymer semiconductor. A physical unclonable function device based on the chiral phototransistor arrays can enhance cryptographic characteristics by encoding the polarization direction of the circularly polarized light.
This article proposes a method and algorithm to automatically generate the propagation supermatrix (PSM) and scattering supermatrix (SSM) from a desired topology network in order to calculate the ...Baum-Liu-Tesche (BLT) equation. Specific forms of the PSM, SSM, and analytical environment based on the definitions adapted by the standard electromagnetic (EM) topology (EMT) methods are proposed. The model is suitable for the EMT analysis with S-parameters and other various values for propagation and scattering situations. The EMT technique is implemented using variables and concepts such as the topology network matrix (TNM) and junction relation matrix (JRM). Additional required parameters are also defined and described. The flow of the whole algorithm and details are illustrated on a simple example for which S-parameters are calculated with the CST-MWS software. A validation of the proposed network formulation is compared to a network resolution made by the Agilent ADS circuit software.
Recently, Si-photonics received a growing interest and started to move from laboratories to industrial product development, mainly for the applications inside data-centers. One of the weaknesses of ...Si is its relatively low plasma dispersion efficiency, making the size of phase modulator large. This efficiency can be improved by using the heterogeneous integration of material such as InP, InGaAsP, or SiGe to fabricate hybrid semiconductor- insulator-semiconductor (SIS) optical phase modulators. At the same time, the standard figure of merit for modulator benchmarking V π L π does not consider the dynamic behavior of the SIS devices, nor is making the link with the system level specifications such as optical modulation amplitude (OMA), widely used in 100G to 400G parallel single mode or coarse wavelength division multiplexing applications. In this paper, we propose to simply link the modulator performance to the OMA, to derive a compact model for SIS devices and to compare hybrid device performances for various materials.
In this study, we analyzed the morphological changes and molecular structure changes on the surface of single-walled carbon nanotube (SWCNT) films during oxygen plasma (O2) etching of SWCNT surfaces ...formed by the spray method and analyzed their potential use as electrochemical electrodes. For this purpose, a SWCNT film was formed on the surface of a glass substrate using a self-made spray device using SWCNT powder prepared with DCB as a solvent, and SEM, AFM, and XPS analyses were performed as the SWCNT film was O2 plasma etched. SEM images and AFM measurements showed that the SWCNT film started etching after about 30 s under 50 W of O2 plasma irradiation and was completely etched after about 300 s. XPS analysis showed that as the O2 plasma etching of the SWCNT film progressed, the sp2 bonds representing the basic components of graphite decreased, the sp3 bonds representing defects increased, and the C–O, C=O, and COO peaks increased simultaneously. This result indicates that the SWCNT film was etched by the O2 plasma along with the oxygen species. In addition, electrochemical methods were used to verify the damage potential of the remaining SWCNTs after O2 plasma etching, including cyclic voltammetry, Randles plots, and EIS measurements. This resulted in a reversible response based on perfect diffusion control in the cyclic voltammetry, and an ideal linear curve in the Randles plot of the peak current versus square root scan rate curve. EIS measurements also confirmed that the charge transfer resistance of the remaining SWCNTs after O2 plasma etching is almost the same as before etching. These results indicate that the remaining SWCNTs after O2 plasma etching do not lose their unique electrochemical properties and can be utilized as electrodes for biosensors and electrochemical sensors. Our experimental results also indicate that the ionic conductivity enhancement by O2 plasma can be achieved additionally.
Sea surface salinity (SSS) is a key parameter in physical oceanography, global hydrological, biochemical cycles, and climate change studies. L-band radiometers onboard satellites, such as Soil ...Moisture Active Passive (SMAP), Soil Moisture and Ocean Salinity (SMOS), have played a crucial role in monitoring and analyzing the global SSS in the past decades. This study presents a method to retrieve and predict the SMAP SSS through data-to-data translation (D2D) based on conditional generative adversarial networks. The model was constructed from the polarized brightness temperatures, differences in the polarized brightness temperatures from the L band of the SMAP satellite, and sea surface temperature and sea surface wind speed from the European Center for Medium-Range Weather Forecasts data from April 2015 to July 2020, and applied to produce SMAP SSS. A comparison between the SMAP salinity and the D2D-generated SMAP salinity showed excellent agreement, evaluated through bias = 0.016, root mean square error (RMSE) = 0.173 in practical salinity unit (psu) units, and correlation coefficient (CC) = 0.985. Furthermore, a comparison between the D2D-generated and buoy-observed salinities showed good agreement (bias = -0.031 psu and RMSE = 0.196 psu, CC = 0.971). Additionally, the results of the one-month prediction model were also in good agreement with the SMAP SSS (bias = 0.028 psu and RMSE = 0.218 psu, CC = 0.977). Consequently, the D2D-based model can be effectively used to generate SMAP SSS information and can be applied to various microwave satellites.
Acute rejection (AR) is critical for long-term graft survival in kidney transplant recipients (KTRs). This study aimed to evaluate the efficacy of the integrated risk score of omics-based biomarkers ...in predicting AR in KTRs. This prospective, randomized, controlled, multicenter, pilot study enrolled 40 patients who recently underwent high-immunologic-risk kidney transplantation (KT). Five omics biomarkers were measured, namely, blood mRNA (three-gene signature), urinary exosomal miRNA (three-gene signature), urinary mRNA (six-gene signature), and two urinary exosomal proteins (hemopexin and tetraspanin-1) at 2 weeks and every 4 weeks after KT for 1 year. An integrated risk score was generated by summing each biomarker up. The biomarker group was informed about the integrated risk scores and used to adjust immunosuppression, but not the control group. The outcomes were graft function and frequency of graft biopsy. Sixteen patients in the biomarker group and nineteen in the control group completed the study. The mean estimated glomerular filtration rate after KT did not differ between the groups. Graft biopsy was performed in two patients (12.5%) and nine (47.4%) in the biomarker and control groups, respectively, with the proportion being significantly lower in the biomarker group (
= 0.027). One patient (6.3%) in the biomarker group and two (10.5%) in the control group were diagnosed with AR, and the AR incidence did not differ between the groups. The tacrolimus trough level was significantly lower in the biomarker group than in the control group at 1 year after KT (
= 0.006). Integrated omics biomarker monitoring may help prevent unnecessary or high-complication-risk biopsy and enables tailored immunosuppression by predicting the risk of AR in KTRs.