The Near Field Refractor

We present an abstract method in the setting of compact metric spaces which is applied to solve a number of problems in geometric optics. In particular, we solve the one source near field refraction problem. That is, we construct surfaces separating two homogenous media with different refractive indices that refract radiation emanating from the origin into a target domain contained in an n-1 dimensional hypersurface. The input and output energy are prescribed. This implies the existence of lenses focusing radiation in a prescribed manner.Comment: 39 pages, 4 figures, Annales de l'Institut Henri Poincare (C) Analyse Non Lineaire (to appear). Geometric optics, lens design, measure equations, Descartes ovals, Monge-Ampere type equation

Refractors in anisotropic media associated with norms

We show existence of interfaces between two anisotropic materials so that light is refracted in accordance with a given pattern of energy. To do this we formulate a vector Snell law for anisotropic media when the wave fronts are given by norms for which the corresponding unit spheres are strictly convex.Comment: 26 pages, 2 figure

The impact of green technology innovation on global value chain upgrading in China’s equipment manufacturing industry

In recent years, China’s equipment manufacturing industry has been actively embedded in the global value chain (GVC), but pollution emission has become an important factor hindering the industry from climbing to the high-end link of GVC. How to break through this restriction through green technology innovation is exactly urgent for the Chinese government and manufacturers. Therefore, using the panel data of China’s equipment manufacturing industry and its subsectors from 2007 to 2019, this paper constructs an econometric model to investigate the impact of green technology innovation on the GVC upgrading, and further examines the mediating effect through stepwise regression method. The results show that for the full samples of China’s equipment manufacturing industry, there is a U-shaped relationship between green technology innovation and the promotion of GVC status; and for basic metals and metal products manufacturing subsector and transport equipment manufacturing subsector, the conclusion is same with the whole industry; but for machinery equipment manufacturing subsector and electrical, electronic and optical equipment manufacturing subsector, the trend is opposite, that is, an inverted U-shaped relationship which first rises and then declines. Additionally, green technology innovation in China’s equipment manufacturing industry can promote GVC upgrading by reducing its dependence on GVC, optimizing export trade, reducing pollution costs, and promoting green product and process innovation. Based on the above, this paper finally proposes targeted policy implications to provide theoretical basis and experience reference for China’s equipment manufacturing industry to promote the GVC upgrading through green technology innovation

Transcription factor Hlx controls a systematic switch from white to brown fat through Prdm16-mediated co-activation

Browning of subcutaneous white fat (iWAT) involves several reprograming events, but the underlying mechanisms are incompletely understood. Here we show that the transcription factor Hlx is selectively expressed in brown adipose tissue (BAT) and iWAT, and is translationally upregulated by beta3-adrenergic signaling-mediated suppression of the translational inhibitor 4E-BP1. Hlx interacts with and is co-activated by Prdm16 to control BAT-selective gene expression and mitochondrial biogenesis. Hlx heterozygous knockout mice have defects in brown-like adipocyte formation in iWAT, and develop glucose intolerance and high fat-induced hepatic steatosis. Conversely, transgenic expression of Hlx at a physiological level drives a full program of thermogenesis and converts iWAT to brown-like fat, which improves glucose homeostasis and prevents obesity and hepatic steatosis. The adipose remodeling phenotypes are recapitulated by fat-specific injection of Hlx knockdown and overexpression viruses, respectively. Our studies establish Hlx as a powerful regulator for systematic white adipose tissue browning and offer molecular insights into the underlying transcriptional mechanism.The transcriptional co-activator Prdm16 regulates browning of white adipose tissue (WAT). Here, the authors show that Prdm16 interacts with the transcription factor Hlx, which is stabilized in response to beta3-adrenergic signaling, to increase thermogenic gene expression and mitochondrial biogenesis in subcutaneous WAT

Fiber Optic Sensor Embedded Smart Helmet for Real-Time Impact Sensing and Analysis through Machine Learning

Background: Mild traumatic brain injury (mTBI) strongly associates with chronic neurodegenerative impairments such as post-traumatic stress disorder (PTSD) and mild cognitive impairment. Early detection of concussive events would significantly enhance the understanding of head injuries and provide better guidance for urgent diagnoses and the best clinical practices for achieving full recovery. New method: A smart helmet was developed with a single embedded fiber Bragg grating (FBG) sensor for real-time sensing of blunt-force impact events to helmets. The transient signals provide both magnitude and directional information about the impact event, and the data can be used for training machine learning (ML) models. Results: The FBG-embedded smart helmet prototype successfully achieved real-time sensing of concussive events. Transient data “fingerprints” consisting of both magnitude and direction of impact, were found to correlate with types of blunt-force impactors. Trained ML models were able to accurately predict (R2 ∼ 0.90) the magnitudes and directions of blunt-force impact events from data not used for model training. Comparison with existing methods: The combination of the smart helmet data with analyses using ML models provides accurate predictions of the types of impactors that caused the events, as well as the magnitudes and the directions of the impact forces, which are unavailable using existing devices. Conclusion: This work resulted in an ML-assisted, FBG-embedded smart helmet for real-time identification of concussive events using a highly accurate multi-metric strategy. The use of ML-FBG smart helmet systems can serve as an early-stage intervention strategy during and immediately following a concussive event

Metasurfaces and Optimal transport

This paper provides a theoretical and numerical approach to show existence, uniqueness, and the numerical determination of metalenses refracting radiation with energy patterns. The theoretical part uses ideas from optimal transport and for the numerical solution we study and implement a damped Newton algorithm to solve the semi discrete problem. A detailed analysis is carried out to solve the near field one source refraction problem and extensions to the far field are also mentioned.Comment: 29 pages, 4 figure

Metabolic Profiling Study of Yang Deficiency Syndrome in Hepatocellular Carcinoma by H

This study proposes a 1H NMR-based metabonomic approach to explore the biochemical characteristics of Yang deficiency syndrome in hepatocellular carcinoma (HCC) based on serum metabolic profiling. Serum samples from 21 cases of Yang deficiency syndrome HCC patients (YDS-HCC) and 21 cases of non-Yang deficiency syndrome HCC patients (NYDS-HCC) were analyzed using 1H NMR spectroscopy and partial least squares discriminant analysis (PLS-DA) was applied to visualize the variation patterns in metabolic profiling of sera from different groups. The differential metabolites were identified and the biochemical characteristics were analyzed. We found that the intensities of six metabolites (LDL/VLDL, isoleucine, lactate, lipids, choline, and glucose/sugars) in serum of Yang deficiency syndrome patients were lower than those of non-Yang deficiency syndrome patients. It implies that multiple metabolisms, mainly including lipid, amino acid, and energy metabolisms, are unbalanced or weakened in Yang deficiency syndrome patients with HCC. The decreased intensities of metabolites including LDL/VLDL, isoleucine, lactate, lipids, choline, and glucose/sugars in serum may be the distinctive metabolic variations of Yang deficiency syndrome patients with HCC. And these metabolites may be potential biomarkers for diagnosis of Yang deficiency syndrome in HCC

Surgical Strategy for the Management of Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus

The hallmark of renal cell carcinoma is its biological characteristic of invading the renal vein and/or inferior vena cava (IVC), which occurs in 4–10% of patients. Radical nephrectomy (RN) with tumor thrombectomy is the standard approach for treating such challenging cases. Except tumor thrombus height, several factors can determine the surgical strategy, including the effect of targeted molecular therapy (TMT), invasion of the IVC wall, venous occlusion, establishment of collateral circulation, IVC thromboembolism, and primary tumor location. The surgical strategy for patients with retrohepatic vena cava tumor thrombi depends on the upper extent of the tumor thrombus. In addition, the first porta hepatis and hepatic veins are important anatomical boundaries. Based on previous studies, the effect of pre-surgical TMT is limited. The safety of IVC venography, an imaging modality that can observe congestion of the tumor thrombus and show the collateral circulation, has considerably improved. IVC interruption plays an important role in tumor thrombectomy for patients with invasion of the venous walls, complete occlusion of the vena cava, and the presence of distal thrombus. A series of retrospective and prospective studies are needed to be conducted, which will provide our clinical work with more powerful reference and basis