Optically manipulated micromirrors for precise excitation of WGM microlasers

Whispering gallery mode microlasers are highly sensitive refractive index sensors widely explored for biophotonic and biomedical applications. Microlaser excitation and collection of the emitted light typically utilize microscope objectives at normal incidence, limiting the choice of the oscillation plane of the modes. Here, we present a platform that enables the excitation of microlasers from various directions using an optically manipulated micromirror. The scheme enables precise sensing of the environment surrounding the microlasers along different well-controlled planes. We further demonstrate the capability of the platform to perform a time-resolved experiment of dynamic sensing using a polystyrene probe bead orbiting the microlaser

Two-tier manipulation of holographic information

The project was supported by the European Research Council (ERC) under the European Union Horizon 2020 research and innovation program (Grant Agreement No. 819346).Here we demonstrate the two-tier manipulation of holographic information using frequency-selective metasurfaces. Our results show that these devices can diffract light efficiently at designed frequency and environmental conditions. By changing the frequency and refractive index of the surrounding environment, the metasurfaces produce two different holographic images. We anticipate that these environmental dependent, frequency-selective metasurfaces will have practical applications in holographic encryption and sensing.Publisher PDFPeer reviewe

Comparison of algorithms for road surface temperature prediction

Purpose - The influence of road surface temperature (RST) on vehicles is becoming more and more obvious. Accurate predication of RST is distinctly meaningful. At present, however, the prediction accuracy of RST is not satisfied with physical methods or statistical learning methods. To find an effective prediction method, this paper selects five representative algorithms to predict the road surface temperature separately. Design/methodology/approach - Multiple linear regressions, least absolute shrinkage and selection operator, random forest and gradient boosting regression tree (GBRT) and neural network are chosen to be representative predictors. Findings - The experimental results show that for temperature data set of this experiment, the prediction effect of GBRT in the ensemble algorithm is the best compared with the other four algorithms. Originality/value - This paper compares different kinds of machine learning algorithms, observes the road surface temperature data from different angles, and finds the most suitable prediction method

Genetic alteration of histone lysine methyltransferases and their significance in renal cell carcinoma

Background Histone lysine methyltransferases (HMTs), a category of enzymes, play essential roles in regulating transcription, cellular differentiation, and chromatin construction. The genomic landscape and clinical significance of HMTs in renal cell carcinoma (RCC) remain uncovered. Methods We conducted an integrative analysis of 50 HMTs in RCC and discovered the internal relations among copy number alterations (CNAs), expressive abundance, mutations, and clinical outcome. Results We confirmed 12 HMTs with the highest frequency of genetic alterations, including seven HMTs with high-level amplification, two HMTs with somatic mutation, and three HMTs with putative homozygous deletion. Patterns of copy number and expression varied among different subtypes of RCC, including clear cell renal cell carcinoma, papillary cell carcinoma, and chromophobe renal carcinoma. Kaplan–Meier survival analysis and multivariate analysis identified that CNA or mRNA expression in some HMTs were significantly associated with shorter overall patient survival. Systematic analysis identified six HMTs (ASH1L, PRDM6, NSD1, EZH2, WHSC1L1, SETD2) which were dysregulated by genetic alterations as candidate therapeutic targets. Discussion In summary, our findings strongly evidenced that genetic alteration of HMTs may play an important role in generation and development of RCC, which lays a solid foundation for the mechanism for further research in the future

Opioid use and opioid use disorder in mono and dual-system users of veteran affairs medical centers

IntroductionEfforts to achieve opioid guideline concordant care may be undermined when patients access multiple opioid prescription sources. Limited data are available on the impact of dual-system sources of care on receipt of opioid medications.ObjectiveWe examined whether dual-system use was associated with increased rates of new opioid prescriptions, continued opioid prescriptions and diagnoses of opioid use disorder (OUD). We hypothesized that dual-system use would be associated with increased odds for each outcome.MethodsThis retrospective cohort study was conducted using Veterans Administration (VA) data from two facilities from 2015 to 2019, and included active patients, defined as Veterans who had at least one encounter in a calendar year (2015–2019). Dual-system use was defined as receipt of VA care as well as VA payment for community care (non-VA) services. Mono users were defined as those who only received VA services. There were 77,225 dual-system users, and 442,824 mono users. Outcomes were three binary measures: new opioid prescription, continued opioid prescription (i.e., received an additional opioid prescription), and OUD diagnosis (during the calendar year). We conducted a multivariate logistic regression accounting for the repeated observations on patient and intra-class correlations within patients.ResultsDual-system users were significantly younger than mono users, more likely to be women, and less likely to report white race. In adjusted models, dual-system users were significantly more likely to receive a new opioid prescription during the observation period [Odds ratio (OR) = 1.85, 95% confidence interval (CI) 1.76–1.93], continue prescriptions (OR = 1.24, CI 1.22–1.27), and to receive an OUD diagnosis (OR = 1.20, CI 1.14–1.27).DiscussionThe prevalence of opioid prescriptions has been declining in the US healthcare systems including VA, yet the prevalence of OUD has not been declining at the same rate. One potential problem is that detailed notes from non-VA visits are not immediately available to VA clinicians, and information about VA care is not readily available to non-VA sources. One implication of our findings is that better health system coordination is needed. Even though care was paid for by the VA and presumably closely monitored, dual-system users were more likely to have new and continued opioid prescriptions

Anthropogenic Aerosols Cause Recent Pronounced Weakening of Asian Summer Monsoon Relative to Last Four Centuries

The Asian Summer Monsoon (ASM) affects ecosystems, biodiversity, and food security of billions of people. In recent decades, ASM strength (as represented by precipitation) has been decreasing, but instrumental measurements span only a short period of time. The initiation and the dynamics of the recent trend are unclear. Here for the first time, we use an ensemble of 10 tree ring-width chronologies from the west-central margin of ASM to reconstruct detail of ASM variability back to 1566 CE. The reconstruction captures weak/strong ASM events and also reflects major locust plagues. Notably, we found an unprecedented 80-year trend of decreasing ASM strength within the context of the 448-year reconstruction, which is contrary to what is expected from greenhouse warming. Our coupled climate model shows that increasing anthropogenic sulfate aerosol emissions over the Northern Hemisphere could be the dominant factor contributing to the ASM decrease. Plan Language Summary Monsoonal rainfall has a certain influence on agriculture and industry in the regions of Asian Summer Monsoon (ASM). An understanding of the spatial-temporal variability of the ASM and the associated dynamics is vital for terrestrial ecosystems, water resources, forests, and landscapes. We have developed a 448-year ASM reconstruction back to 1566 CE using 10 tree ring chronologies from the margin region of ASM. We find that historical severe droughts and locust plague disasters during weak ASM events. The recent decreasing ASM trend persisting for over 80 years is unprecedented over the past 448 years. Coupled climate models show that increasing anthropogenic aerosol emissions are the dominant underlying factor. Our aim is that the time series will find a wide range of utility for understanding past climate variability and for predicting future climate change.National Natural Science Foundation of China [41630531]; National Research Program for Key Issues in Air Pollution Control [DQGG0104]; Chinese Academy of Sciences [QYZDJ-SSW-DQC021, XDPB05, GJHZ1777]; Institute of Earth Environment, Chinese Academy of Sciences; State Key Laboratory of Loess and Quaternary Geology6 month embargo; first published: 09 April 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Meta-fluidic-surfaces for electromagnetic wave manipulations

Metasurfaces are subwavelength-thick planar materials artificially designed with distinctive electromagnetic properties. The flexibility of tailoring both the permittivity and permeability of the metasurface enables its extraordinary electromagnetic response that cannot be found in natural materials. The extraordinary electromagnetic properties of metasurfaces lead to many promising and practical applications. This doctorate thesis focuses on the design, simulation, fabrication and experimental measurement of meta-fluidic-surface for tailoring the optical properties of electromagnetic waves. Specifically, three types of meta-fluidic-surface is studied and discussed, namely: (1) dispersion-controllable metasurface for tailoring the dispersion property of metasurface; (2) polarization-independent tunable metasurface for polarization-independent beam control, and (3) Tunable birefringent metasurface for the manipulation of birefringence.Doctor of Philosoph

Compact wideband wide-angle van atta retroreflector with suppressed structural mode

A passive miniaturized wideband, wide-angle, and low structural mode Van Atta retroreflector for copolarized applications is presented. The proposed Van Atta retroreflector is composed of eight radiating elements interconnected in pairs with a planar feeding network of microstrip lines. Furthermore, the radiating element consists of a compact dielectric-filled open-ended waveguide. The dielectric filling is designed with rectangular pyramid trench to ensure the broadband feature of the open-ended waveguide, while minimizing the dimensions. In addition, the microstrip lines are designed on the two side walls of the Van Atta retroreflector, which are parallel to the incident plane, to suppress the structural mode contributed by the feeding network. The designed Van Atta retroreflector is verified by simulations and experiments with 40% fractional bandwidth centered at 10 GHz. The monostatic radar cross section (RCS) shows that the -10 dB beamwidth is about 80^circ over the frequency range of interest. Meanwhile, the bistatic RCS indicates that the sidelobe level is less than -10 dB for copolarized retroreflection from -25^circ to 25^circ over the frequency range of 9.5-10.5 GHz