22 research outputs found

    Estimation and inference for minimizer and minimum of convex functions: optimality, adaptivity and uncertainty principles

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    Optimal estimation and inference for both the minimizer and minimum of a convex regression function under the white noise and nonparametric regression models are studied in a nonasymptotic local minimax framework, where the performance of a procedure is evaluated at individual functions. Fully adaptive and computationally efficient algorithms are proposed and sharp minimax lower bounds are given for both the estimation accuracy and expected length of confidence intervals for the minimizer and minimum. The nonasymptotic local minimax framework brings out new phenomena in simultaneous estimation and inference for the minimizer and minimum. We establish a novel uncertainty principle that provides a fundamental limit on how well the minimizer and minimum can be estimated simultaneously for any convex regression function. A similar result holds for the expected length of the confidence intervals for the minimizer and minimum

    Supra-additive effect of chronic inflammation and atherogenic dyslipidemia on developing type 2 diabetes among young adults: A prospective cohort study

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    Background: Both elevated inflammation and atherogenic dyslipidemia are prominent in young-onset diabetes and are increasingly identified as biologically intertwined processes that contribute to diabetogenesis. We aimed to investigate the age-specific risks of type 2 diabetes (T2D) upon concomitant chronic inflammation and atherogenic dyslipidemia. Methods: Age-stratified Cox regression analysis of the risk of incident diabetes upon co-exposure to time-averaged cumulative high-sensitivity C-reactive protein (CumCRP) and atherogenic index of plasma (CumAIP) among 42,925 nondiabetic participants from a real-world, prospective cohort (Kailuan Study). Results: During a median 6.41 years of follow-up, 3987 T2D developed. Isolated CumAIP and CumCRP were significantly associated with incident T2D in the entire cohort and across all age subgroups. Both CumAIP and CumCRP were jointly associated with an increased risk of diabetes (P-interaction = 0.0126). Compared to CumAIP \u3c -0.0699 and CumCRP \u3c 1 mg/L, co-exposure to CumAIP ā‰„ āˆ’ 0.0699 and CumCRP ā‰„ 3 mg/L had a significant hazard ratio (HR) [2.55 (2.23ā€“2.92)] after adjusting for socio-demographic, life-style factors, family history of diabetes, blood pressure, renal function and medication use. The co-exposure-associated risks varied greatly by age distribution (P-interaction = 0.0193): \u3c 40 years, 6.26 (3.47ā€“11.28); 40ā€“49 years, 2.26 (1.77ā€“2.89); 50ā€“59 years, 2.51 (2.00ā€“3.16); 60ā€“69 years, 2.48 (1.86ā€“3.30); ā‰„ 70 years, 2.10 (1.29ā€“3.40). In young adults ( \u3c 45 years), both exposures had a significant supra-additive effect on diabetogenesis (relative excess risk due to interaction: 0.80, 95% CI 0.10ā€“1.50). Conclusions: These findings highlight the need for age-specific combined assessment and management of chronic inflammation and dyslipidemia in primary prevention against T2D, particularly for young adults. The clinical benefit derived from dual-target intervention against dyslipidemia and inflammation will exceed the sum of each part alone in young adults

    Inhibiting Phase Transfer of Protein Nanoparticles by Surface Camouflage-A Versatile and Efficient Protein Encapsulation Strategy

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    Engineering a system with a high mass fraction of active ingredients, especially water-soluble proteins, is still an ongoing challenge. In this work, we developed a versatile surface camouflage strategy that can engineer systems with an ultrahigh mass fraction of proteins. By formulating protein molecules into nanoparticles, the demand of molecular modification was transformed into a surface camouflage of protein nanoparticles. Thanks to electrostatic attractions and van der Waals interactions, we camouflaged the surface of protein nanoparticles through the adsorption of carrier materials. The adsorption of carrier materials successfully inhibited the phase transfer of insulin, albumin, Ī²-lactoglobulin, and ovalbumin nanoparticles. As a result, the obtained microcomposites featured with a record of protein encapsulation efficiencies near 100% and a record of protein mass fraction of 77%. After the encapsulation in microcomposites, the insulin revealed a hypoglycemic effect for at least 14 d with one single injection, while that of insulin solution was only āˆ¼4 h.Peer reviewe

    Multi-Twin-SSB Modulation with Direct Detection Based on Kramersā€“Kronig Scheme for Long-Reach PON Downstream

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    As the demand for high data volumes keeps increasing in optical access networks, transmission capacities and distance are becoming bottlenecks for passive optical networks (PONs). To solve this problem, a novel scheme based on multi-twin single sideband (SSB) modulation with direct detection is proposed and investigated in this paper. At the central office, two SSB signals are generated simultaneously with the same digital-to-analog converters (DACs). The twin-SSB signal is not only robust against frequency selected power fading introduced by chromatic dispersion (CD), but also improves the spectral efficiency (SE). By combining a twin-SSB technique with multi-band carrier-less amplitude/phase modulation (multi-CAP), different optical network units (ONUs) can be supported by flexible multi-band allocation based on software-reconfigurable optical transceivers. The Kramers⁻Kronig (KK) scheme is adopted on the ONU side to effectively mitigate the signal⁻signal beat interference (SSBI) induced by the square-law detection. The proposed system is extensively studied and validated with four sub-bands using 50 Gbps 16 quadrature amplitude modulation (QAM) modulation for each sub-band using numerical simulations. Digital pre-equalization is introduced at the transmitter-side to balance the performance of different ONUs. After system optimization, a bit error rate (BER) threshold for hard decision forward error correction (HD-FEC) code with 7% redundancy ratio (BER = 3.8 × 10−3) can be reached for all ONUs over 50-km standard single-mode fiber

    Study on Construction Response Characteristics of Large Cross-Section Tunnel Crossing Huge Karst Cave Backfill

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    The existence of giant karst cave can cause collapse and water inrush hazards during the excavation of the karst tunnel, causing serious economic losses. In this paper, based on the FEA software MIDAS, a numerical simulation model for the backfilling of a large karst cave through a large cross-section tunnel was established. The distribution characteristics and change rules of the displacement field, stress field, horizontal support stress, and plastic zone of the tunnel surrounding rock and backfill were explored. The first stage of tunnel excavation leads to a sharp increase in the displacement of the tunnelā€™s surrounding rock and the deterioration of the plastic zone, which should be strengthened and monitored. The tunnel arch, waist, and wall footing areas were prone to stress concentration. The two layers of horizontal support force show a certain regularity, showing a sharp increase and a gradually smooth growth trend. Meanwhile, the site monitoring results for arch settlement and horizontal convergence of the mega cavern tunnel were analyzed. The results show that the numerical calculation results were in good agreement with the values of site monitoring data. The average errors of final crown settlement and horizontal convergence were 8.6% and 15.9%, respectively, which verified the correctness of the numerical modeling method. This project can provide reliable experience for the construction of similar large cavern tunnels

    Fano-Resonant Hybrid Metamaterial for Enhanced Nonlinear Tunability and Hysteresis Behavior

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    Artificial resonant metamaterial with subwavelength localized filed is promising for advanced nonlinear photonic applications. In this article, we demonstrate enhanced nonlinear frequency-agile response and hysteresis tunability in a Fano-resonant hybrid metamaterial. A ceramic cuboid is electromagnetically coupled with metal cut-wire structure to excite the high-Q Fano-resonant mode in the dielectric/metal hybrid metamaterial. It is found that the significant nonlinear response of the ceramic cuboid can be employed for realization of tunable metamaterials by exciting its magnetic mode, and the trapped mode with an asymmetric Fano-like resonance is beneficial to achieve notable nonlinear modulation on the scattering spectrum. The nonlinear tunability of both the ceramic structure and the ceramic/metal hybrid metamaterial is promising to extend the operation band of metamaterials, providing possibility in practical applications with enhanced light-matter interactions

    Influence of bone mineral density and hip geometry on the different types of hip fracture

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    The aim of this study was to assess the influence of bone mineral density and hip geometry on the fragility fracture of femoral neck and trochanteric region. There were 95 menopausal females of age ā‰„ 50 years with fragility fracture of hip, including 55 cases of femoral neck fracture and 40 cases of trochanteric fracture. Another 63 non-fractured females with normal bone mineral density (BMD) were chosen as control. BMD, hip axis length, neck-shaft angle and structural parameters including cross surface area, cortical thickness and buckling ratio were detected and compared. Compared with control group, the patients with femoral neck fracture or trochanteric fractures had significantly lower BMD of femoral neck, as well as lower cross surface area and cortical thickness and higher buckling ratio in femoral neck and trochanteric region. There were no significant differences of BMD and structural parameters in the femoral neck fracture group and intertrochanteric fracture group. Hip axis length and neck-shaft angle were not significantly different among three groups. The significant changes of BMD and proximal femur geometry were present in the fragility fracture of femoral neck and trochanteric region. The different types of hip fractures cannot be explained by these changes
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