Showing 1–22 of 22 results for author: Fan, F

Sublime Transfer Printing of Three-Dimensional Nanostructure Ensembles

Authors: Lei Chen, Hao Wang, Wang Zhang, Fu Fan, Peng Liu, Xiaoxue Bi, John You En Chan, Cheng-Feng Pan, Bochang Wu, Zhengchao Liu, Rou Yun Teo, Hongtao Wang, Huigao Duan, Joel K. W. Yang

Abstract: High-resolution three-dimensional (3D) nanostructures for visible-light photon manipulation provide unique and bespoke capabilities in optics and photonics. However subwavelength nanofabrication and reliable ensemble manipulation of the 3D prints onto arbitrary substrates remain challenging. Here, we introduce sublime transfer strategy tailored for transfer printing ensembles of delicate 3D printe… ▽ More High-resolution three-dimensional (3D) nanostructures for visible-light photon manipulation provide unique and bespoke capabilities in optics and photonics. However subwavelength nanofabrication and reliable ensemble manipulation of the 3D prints onto arbitrary substrates remain challenging. Here, we introduce sublime transfer strategy tailored for transfer printing ensembles of delicate 3D printed nanostructures. This strategy enables conformal, damage-free integration of arrays of 3D structures on diverse substrates. Naphthalene acts as a transient stamp to encapsulate the structures during transfer and placement. We rely on the low sublimation temperature of naphthalene to release the structures reliably with nearly zero stress, preventing mechanical damage and positional misalignment. This approach is broadly applicable to integrate diverse nanostructures and photonic devices onto various substrates, and enabling inorganic architectures through ensemble uniform post-processing, including 2.5D photonic crystals on flexible PDMS, diffractive optical elements on curved lenses, spiral phase plates on CMOS chips, multilayer achromatic metalens on optical fiber facet, as well as 3D glass photonic crystals and optical topological resonators on anti-stiction quartz. △ Less

Submitted 17 August, 2026; originally announced August 2026.

Generating synthetic computed tomography for radiotherapy: SynthRAD2025 challenge report

Authors: Viktor Rogowski, Maarten L. Terpstra, Niklas Wahl, Florian Kamp, Erik van der Bijl, Arthur Jr. Galapon, Christopher Kurz, Bowen Xin, Zhengxiang Sun, Hollie Min, Gregg Belous, Jason Dowling, Yan Xia, Siyuan Mei, Fuxin Fan, Arthur Longuefosse, Javier Sequeiro Gonzalez, Miguel Diaz Benito, Alvaro Garcia Martin, Fabien Baldacci, Valentin Boussot, Cédric Hémon, Jean-Claude Nunes, Jean-Louis Dillenseger, Zhiyuan Zhang , et al. (8 additional authors not shown)

Abstract: Radiation therapy (RT) requires precise dose delivery over multiple fractions, with CT fundamental for treatment planning due to its electron density information. Repeated CT acquisitions impose radiation exposure and logistical burdens, MRI lacks electron density, and cone-beam CT (CBCT) requires correction for dose calculation. Synthetic CT (sCT) generation addresses these by converting MRI or C… ▽ More Radiation therapy (RT) requires precise dose delivery over multiple fractions, with CT fundamental for treatment planning due to its electron density information. Repeated CT acquisitions impose radiation exposure and logistical burdens, MRI lacks electron density, and cone-beam CT (CBCT) requires correction for dose calculation. Synthetic CT (sCT) generation addresses these by converting MRI or CBCT into CT-equivalent images with accurate Hounsfield Unit (HU) values, enabling MRI-only RT and CBCT-based adaptive workflows. Building on SynthRAD2023, SynthRAD2025 benchmarked sCT methods on 2,362 patients from five European centers across head and neck, thorax, and abdomen. Two tasks: MRI-to-CT (890 cases) and CBCT-to-CT (1,472 cases), evaluated via image similarity (MAE, PSNR, MS-SSIM), segmentation (Dice, HD95), and dosimetric metrics from photon and proton plans. With 803 participants and 12/13 valid submissions, Task 1 top performance reached MAE $64.8\pm21.3$ HU, PSNR $\sim$30 dB, MS-SSIM $\sim$0.936, Dice 0.79, photon $γ_{2\%/2\text{mm}}>98\%$, proton $γ\approx85\%$. Task 2 improved: MAE $48.3\pm13.4$ HU, PSNR 32.6 dB, MS-SSIM 0.968, Dice 0.86, photon $γ>99\%$, proton $γ\approx89\%$. Strong image--segmentation correlations ($ρ=0.78$--$0.79$) but moderate dose correlations confirmed image quality is insufficient as a dosimetric surrogate. Head-and-neck cases were most consistent; thoracic and abdominal cases showed greater variability. Residual errors at tissue interfaces propagate along beam paths, affecting proton dose more than photon. SynthRAD2025 demonstrates that deep learning yields clinically relevant sCTs, especially for CBCT-to-CT, while identifying persistent MRI-to-CT challenges and underscoring dose-based evaluation as essential for clinical validation. △ Less

Submitted 13 May, 2026; originally announced May 2026.

Comments: 59 pages total: 26 pages main article + supplementary material; 8 figures in the main manuscript and 3 supplementary figures. Currently under review at the journal Medical Image Analysis (MIA)

Precision measurement and modelling of the threshold-free 210Pb β spectrum

Authors: Shuo Zhang, Hao-Ran Liu, Ke Han, Xavier Mougeot, Paul-Antoine Hervieux, Tao Sun, Wen-Tao Wu, Robin Cantor, Jing-Kai Xia, Zhi Liu, Jun-Cheng Liang, Fu-You Fan, Le Zhang, Ming-Yu Ge, Xiao-Peng Zhou, Adrien Andoche

Abstract: Beta decay is a fundamental process that governs nuclear stability and serves as a sensitive probe of the weak interaction and possible physics beyond the Standard Model of particle physics. However, precise measurements of complete $β$ decay spectra, particularly at low energies, remain experimentally and theoretically challenging. Here we report a high-precision, threshold-free measurement of th… ▽ More Beta decay is a fundamental process that governs nuclear stability and serves as a sensitive probe of the weak interaction and possible physics beyond the Standard Model of particle physics. However, precise measurements of complete $β$ decay spectra, particularly at low energies, remain experimentally and theoretically challenging. Here we report a high-precision, threshold-free measurement of the full $β$ decay spectrum of 210Pb to excited states of 210Bi, using a transition-edge sensor (TES)-based micro-calorimeter. This approach enables the detection of $β$ particle energies from 0 keV up to their endpoint by coincidence summing with subsequent de-excitation energy, thereby eliminating reconstruction artifacts near zero energy that have traditionally limited low-energy spectral accuracy. To our knowledge, this is the first complete, high-precision $β$ decay spectrum from 0 keV. The data resolve theoretical uncertainties associated with the atomic quantum exchange (AQE) effect. An accompanying ab initio theoretical framework, incorporating atomic, leptonic, and nuclear components, predicts a statistically significant (7.2 {$σ$}) enhancement in $β$ emission probability near zero energy, in agreement with the measurement and in contrast to models that omit AQE corrections. These results provide a new benchmark for $β$ decay theory at low energies, deepen our understanding of the weak interaction, and establish a critical foundation for searches for new physics, including dark matter interactions and precision studies of neutrinos. △ Less

Submitted 1 October, 2025; v1 submitted 30 September, 2025; originally announced September 2025.

Comments: 14 pages, 7 figures

Generating Synthetic Computed Tomography for Radiotherapy: SynthRAD2023 Challenge Report

Authors: Evi M. C. Huijben, Maarten L. Terpstra, Arthur Jr. Galapon, Suraj Pai, Adrian Thummerer, Peter Koopmans, Manya Afonso, Maureen van Eijnatten, Oliver Gurney-Champion, Zeli Chen, Yiwen Zhang, Kaiyi Zheng, Chuanpu Li, Haowen Pang, Chuyang Ye, Runqi Wang, Tao Song, Fuxin Fan, Jingna Qiu, Yixing Huang, Juhyung Ha, Jong Sung Park, Alexandra Alain-Beaudoin, Silvain Bériault, Pengxin Yu , et al. (34 additional authors not shown)

Abstract: Radiation therapy plays a crucial role in cancer treatment, necessitating precise delivery of radiation to tumors while sparing healthy tissues over multiple days. Computed tomography (CT) is integral for treatment planning, offering electron density data crucial for accurate dose calculations. However, accurately representing patient anatomy is challenging, especially in adaptive radiotherapy, wh… ▽ More Radiation therapy plays a crucial role in cancer treatment, necessitating precise delivery of radiation to tumors while sparing healthy tissues over multiple days. Computed tomography (CT) is integral for treatment planning, offering electron density data crucial for accurate dose calculations. However, accurately representing patient anatomy is challenging, especially in adaptive radiotherapy, where CT is not acquired daily. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast. Still, it lacks electron density information while cone beam CT (CBCT) lacks direct electron density calibration and is mainly used for patient positioning. Adopting MRI-only or CBCT-based adaptive radiotherapy eliminates the need for CT planning but presents challenges. Synthetic CT (sCT) generation techniques aim to address these challenges by using image synthesis to bridge the gap between MRI, CBCT, and CT. The SynthRAD2023 challenge was organized to compare synthetic CT generation methods using multi-center ground truth data from 1080 patients, divided into two tasks: 1) MRI-to-CT and 2) CBCT-to-CT. The evaluation included image similarity and dose-based metrics from proton and photon plans. The challenge attracted significant participation, with 617 registrations and 22/17 valid submissions for tasks 1/2. Top-performing teams achieved high structural similarity indices (>0.87/0.90) and gamma pass rates for photon (>98.1%/99.0%) and proton (>97.3%/97.0%) plans. However, no significant correlation was found between image similarity metrics and dose accuracy, emphasizing the need for dose evaluation when assessing the clinical applicability of sCT. SynthRAD2023 facilitated the investigation and benchmarking of sCT generation techniques, providing insights for developing MRI-only and CBCT-based adaptive radiotherapy. △ Less

Submitted 11 June, 2024; v1 submitted 13 March, 2024; originally announced March 2024.

Comments: Preprint submitted to Medical Image Analysis

Tunable Polarization-Multiplexed Achromatic Dielectric Metalens

Authors: Xiangnian Ou, Tibin Zeng, Yi Zhang, Yuting Jiang, Zhongwei Gong, Fan Fan, Honghui Jia, Huigao Duan, Yueqiang Hu

Abstract: Tunable metasurfaces provide a compact and efficient strategy for optical components that require active wavefront shaping. Varifocal metalens is one of the most important applications. However, the existing tunable metalens rarely serves broadband wavelengths restricting their applications in broadband imaging and color display due to chromatic aberration. Herein, we demonstrate an electrically t… ▽ More Tunable metasurfaces provide a compact and efficient strategy for optical components that require active wavefront shaping. Varifocal metalens is one of the most important applications. However, the existing tunable metalens rarely serves broadband wavelengths restricting their applications in broadband imaging and color display due to chromatic aberration. Herein, we demonstrate an electrically tunable polarization-multiplexed varifocal achromatic dielectric metalens integrated with twisted nematic liquid crystals (TNLCs) in the visible region. The phase profiles at different wavelengths under two orthogonal polarization channels are customized by the particle swarm optimization algorithm and optimally matched with the metaunits database to achieve polarization-multiplexed dispersion manipulation including achromatic performance. By combining the broadband linear polarization conversion ability of TNLC, the tunability of varifocal achromatic metalens is realized by applying different voltages. Further, the electrically tunable customized dispersion-manipulated metalens and switchable color metaholograms are demonstrated. The proposed devices will accelerate the application of metasurfaces in broadband zoom imaging, AR/VR displays, and spectral detection. △ Less

Submitted 31 August, 2022; originally announced September 2022.

In-Circuit Impedance Measurement Setups of Inductive Coupling Approach: A Review

Authors: Zhenyu Zhao, Fei Fan, Huamin Jie, Zhenning Yang, Minghai Dong, Eng Kee Chua, Kye Yak See

Abstract: In-circuit impedance measurement provides useful information for many EMC applications. The inductive coupling approach is a promising in-circuit impedance measurement method due to its non-contact characteristics and simple on-site implementation. Many measurement setups of this approach were reported. However, a comprehensive survey and comparison of these setups have not been found in the liter… ▽ More In-circuit impedance measurement provides useful information for many EMC applications. The inductive coupling approach is a promising in-circuit impedance measurement method due to its non-contact characteristics and simple on-site implementation. Many measurement setups of this approach were reported. However, a comprehensive survey and comparison of these setups have not been found in the literature. This paper reviews these setups in terms of their characteristics, limitations, and applications. In addition, recommendations for future research are also presented. △ Less

Submitted 14 April, 2022; originally announced April 2022.

Comments: The paper has been accepted to be presented at the 2022 Asia-Pacific International Symposium on Electromagnetic Compatibility (APEMC) in July 2022

Inductively Coupled In-Circuit Impedance Measurement and Its EMC Applications

Authors: Zhenyu Zhao, Fei Fan, Huamin Jie, Quqin Sun, Pengfei Tu, Wensong Wang, Kye Yak See

Abstract: In-circuit impedance provides key information for many EMC applications. The inductive coupling approach is a promising method for in-circuit impedance measurement because its measurement setups have no direct electrical contact with the energized system under test, thus greatly simplifying the on-site implementation. This paper presents and summaries the latest research on the inductive coupling… ▽ More In-circuit impedance provides key information for many EMC applications. The inductive coupling approach is a promising method for in-circuit impedance measurement because its measurement setups have no direct electrical contact with the energized system under test, thus greatly simplifying the on-site implementation. This paper presents and summaries the latest research on the inductive coupling approach and its EMC applications. First of all, three common measurement setups for this approach and their respective pros and cons are discussed. Subsequently, their EMC applications are introduced. Finally, recommendations for future research are listed. △ Less

Submitted 30 March, 2022; originally announced April 2022.

Transition edge sensor based detector: from X-ray to $γ$-ray

Authors: Shuo Zhang, Jing-Kai Xia, Tao Sun, Wen-Tao Wu, Bing-Jun Wu, Yong-Liang Wang, Robin Cantor, Ke Han, Xiao-Peng Zhou, Hao-Ran Liu, Fu-You Fan, Si-Ming Guo, Jun-Cheng Liang, De-Hong Li, Yan-Ru Song, Xu-Dong Ju, Qiang Fu, Zhi Liu

Abstract: The Transition Edge Sensor is extremely sensitive to the change of temperature, combined with the high-Z metal of a certain thickness, it can realize the high energy resolution measurement of particles such as X-rays. X-rays with energies below 10 keV have very weak penetrating ability, so only a few microns thick of gold or bismuth can obtain quantum efficiency higher than 70\%. Therefore, the en… ▽ More The Transition Edge Sensor is extremely sensitive to the change of temperature, combined with the high-Z metal of a certain thickness, it can realize the high energy resolution measurement of particles such as X-rays. X-rays with energies below 10 keV have very weak penetrating ability, so only a few microns thick of gold or bismuth can obtain quantum efficiency higher than 70\%. Therefore, the entire structure of the TES X-ray detector in this energy range can be realized in the microfabrication process. However, for X-rays or gamma rays from 10 keV to 200 keV, sub-millimeter absorber layers are required, which cannot be realized by microfabrication process. This paper first briefly introduces a set of TES X-ray detectors and their auxiliary systems built by ShanghaiTech University, then focus on the introduction of the TES $γ$-ray detector, with absorber based on an sub-millimeter lead-tin alloy sphere. The detector has a quantum efficiency above 70\% near 100 keV, and an energy resolution of about 161.5eV@59.5keV. △ Less

Submitted 26 April, 2022; v1 submitted 1 April, 2022; originally announced April 2022.

Comments: 13 pages, 12 figures

MSC Class: 81V35

Measurement of In-Circuit Common-Mode Impedance at the AC Input of a Motor Drive System

Authors: Zhenyu Zhao, Fei Fan, Arjuna Weerasinghe, Pengfei Tu, Kye Yak See

Abstract: The in-circuit common-mode (CM) impedance at the AC input of a motor drive system (MDS) provides valuable inputs for evaluating and estimating the CM electromagnetic interference (EMI) noise generated by the switching of power semiconductor devices in the MDS. This paper introduces a single-probe setup (SPS) with frequency-domain measurement to extract the in-circuit CM impedance of a MDS under it… ▽ More The in-circuit common-mode (CM) impedance at the AC input of a motor drive system (MDS) provides valuable inputs for evaluating and estimating the CM electromagnetic interference (EMI) noise generated by the switching of power semiconductor devices in the MDS. This paper introduces a single-probe setup (SPS) with frequency-domain measurement to extract the in-circuit CM impedance of a MDS under its different operating modes. The SPS has the merits of non-contact measurement and simple structure. △ Less

Submitted 18 October, 2021; v1 submitted 5 October, 2021; originally announced October 2021.

Comments: This is a modified/final version of arXiv:2110.04068

Impact of Motor Stator Winding Faults on Common-Mode Current

Authors: Fei Fan, Zhenyu Zhao, Pengfei Tu, Huamin Jie, Kye Yak See

Abstract: This paper investigates the influence of different motor stator failures on the common-mode (CM) current. The stator winding failures will affect the motor's CM impedance, and also increase the unbalance of the differential-mode (DM) noise path. The experimental results show that the former will increase the CM current induced by the CM noise source, while the latter will cause the DM current indu… ▽ More This paper investigates the influence of different motor stator failures on the common-mode (CM) current. The stator winding failures will affect the motor's CM impedance, and also increase the unbalance of the differential-mode (DM) noise path. The experimental results show that the former will increase the CM current induced by the CM noise source, while the latter will cause the DM current induced by the DM noise source to be converted into the CM current. △ Less

Submitted 5 October, 2021; originally announced October 2021.

Comments: The conference paper has been accepted by APEMC 2021, which is to be published in IEEE Xplore soon

First demonstration of in-beam performance of bent Monolithic Active Pixel Sensors

Authors: ALICE ITS project, :, G. Aglieri Rinella, M. Agnello, B. Alessandro, F. Agnese, R. S. Akram, J. Alme, E. Anderssen, D. Andreou, F. Antinori, N. Apadula, P. Atkinson, R. Baccomi, A. Badalà, A. Balbino, C. Bartels, R. Barthel, F. Baruffaldi, I. Belikov, S. Beole, P. Becht, A. Bhatti, M. Bhopal, N. Bianchi , et al. (230 additional authors not shown)

Abstract: A novel approach for designing the next generation of vertex detectors foresees to employ wafer-scale sensors that can be bent to truly cylindrical geometries after thinning them to thicknesses of 20-40$μ$m. To solidify this concept, the feasibility of operating bent MAPS was demonstrated using 1.5$\times$3cm ALPIDE chips. Already with their thickness of 50$μ$m, they can be successfully bent to ra… ▽ More A novel approach for designing the next generation of vertex detectors foresees to employ wafer-scale sensors that can be bent to truly cylindrical geometries after thinning them to thicknesses of 20-40$μ$m. To solidify this concept, the feasibility of operating bent MAPS was demonstrated using 1.5$\times$3cm ALPIDE chips. Already with their thickness of 50$μ$m, they can be successfully bent to radii of about 2cm without any signs of mechanical or electrical damage. During a subsequent characterisation using a 5.4GeV electron beam, it was further confirmed that they preserve their full electrical functionality as well as particle detection performance. In this article, the bending procedure and the setup used for characterisation are detailed. Furthermore, the analysis of the beam test, including the measurement of the detection efficiency as a function of beam position and local inclination angle, is discussed. The results show that the sensors maintain their excellent performance after bending to radii of 2cm, with detection efficiencies above 99.9% at typical operating conditions, paving the way towards a new class of detectors with unprecedented low material budget and ideal geometrical properties. △ Less

Submitted 17 August, 2021; v1 submitted 27 May, 2021; originally announced May 2021.

Electrically Tunable Multifunctional All-Dielectric Metasurfaces Integrated with Liquid Crystals in the Visible

Authors: Yueqiang Hu, Xiangnian Ou, Tibin Zeng, Jiajie Lai, Jian Zhang, Xin Li, Xuhao Luo, Ling Li, Fan Fan, Huigao Duan

Abstract: As two-dimensional metamaterials, metasurfaces open up new avenues for designing static planar optics. However, the dynamic modulation of metasurfaces in the optical band is required for practical applications. The existing dynamic devices rarely utilized the polarization manipulation capability of metasurfaces. Here, we demonstrate an electrically tunable multifunctional metasurface in the visibl… ▽ More As two-dimensional metamaterials, metasurfaces open up new avenues for designing static planar optics. However, the dynamic modulation of metasurfaces in the optical band is required for practical applications. The existing dynamic devices rarely utilized the polarization manipulation capability of metasurfaces. Here, we demonstrate an electrically tunable multifunctional metasurface in the visible range by integrating birefringent liquid crystals (LCs) with all-dielectric metasurfaces based on a novel packaging scheme. By combining the helicity-dependent geometric phase of the metasurface and the polarization control ability of LC molecules, continuous intensity tuning and switching of two helicity channels are realized. Electrically tunable single-channel switchable metaholograms, multicolor multiplexed metaholograms, and dynamic varifocal metalenses are designed to verify the concept. The exploration of polarization control in dynamic tuning can pave the way for dynamic metasurface devices in various applications, such as space light modulators, light detection and ranging systems, and holographic displays. △ Less

Submitted 24 December, 2020; originally announced December 2020.

Suppression of axionic charge density wave and onset of superconductivity in the chiral Weyl semimetal Ta$_2$Se$_8$I

Authors: Qing-Ge Mu, Dennis Nenno, Yan-Peng Qi, Feng-Ren Fan, Cuiying Pei, Moaz ElGhazali, Johannes Gooth, Claudia Felser, Prineha Narang, Sergey Medvedev

Abstract: A Weyl semimetal with strong electron-phonon interaction can show axionic coupling in its insulator state at low temperatures, owing to the formation of a charge density wave (CDW). Such a CDW emerges in the linear chain compound Weyl semimetal Ta$_2$Se$_8$I below 263 K, resulting in the appearance of the dynamical condensed-matter axion quasiparticle. In this study, we demonstrate that the interc… ▽ More A Weyl semimetal with strong electron-phonon interaction can show axionic coupling in its insulator state at low temperatures, owing to the formation of a charge density wave (CDW). Such a CDW emerges in the linear chain compound Weyl semimetal Ta$_2$Se$_8$I below 263 K, resulting in the appearance of the dynamical condensed-matter axion quasiparticle. In this study, we demonstrate that the interchain coupling in Ta$_2$Se$_8$I can be varied to suppress the CDW formation with pressure, while retaining the Weyl semimetal phase at high temperatures. Above 17 GPa, the Weyl semimetal phase does not survive and we induce superconductivity, due to the amorphization of the iodine sub-lattice. Structurally, the one-dimensional Ta-Se-chains remain intact and provide a superconducting channel in one dimension. We highlight that our results show a near-complete suppression of the gap induced by the axionic charge-density wave at pressures inaccessible to previous studies. Including this CDW phase, our experiments and theoretical predictions and analysis reveal the complete topological phase diagram of Ta$_2$Se$_8$I and its relationship to the nearby superconducting state. The results demonstrate Ta$_2$Se$_8$I to be a distinctively versatile platform for exploring correlated topological states. △ Less

Submitted 14 October, 2020; originally announced October 2020.

Comments: 8 pages, 4 figures

Journal ref: Phys. Rev. Materials 5, 084201 (2021)

Room-temperature Continuous-wave Lasing from Monolayer Molybdenum Ditelluride with a Silicon Nanobeam Cavity

Authors: Yongzhuo Li, Jianxing Zhang, Dandan Huang, Hao Sun, Fan Fan, Jiabi Feng, Zhen Wang, C. Z. Ning

Abstract: Monolayer transition metal dichalcogenides (TMDs) provide the most efficient optical gain materials and have potential for making nanolasers with the smallest gain media with lowest energy consumption. But lasing demonstrations based on TMDs have so far been limited to low temperatures. Here, we demonstrate the first room-temperature laser operation in the infrared wavelengths from a monolayer of… ▽ More Monolayer transition metal dichalcogenides (TMDs) provide the most efficient optical gain materials and have potential for making nanolasers with the smallest gain media with lowest energy consumption. But lasing demonstrations based on TMDs have so far been limited to low temperatures. Here, we demonstrate the first room-temperature laser operation in the infrared wavelengths from a monolayer of molybdenum ditelluride on a silicon photonic-crystal nanobeam cavity. Our demonstration is made possible by a unique choice of TMD material with emission wavelength below silicon absorption, combined with the high Q-cavity design by silicon nanobeam. Lasing at 1132 nm is demonstrated at room-temperature pumped by a continuous-wave laser, with a threshold density at 6.6 W/cm2. The room-temperature linewidth of 0.202 nm is the narrowest with the corresponding Q of 5603, the largest observed for a TMD laser. This demonstration establishes TMDs as practical nanolaser materials. The silicon structures provide additional benefits for silicon-compatible nanophotonic applications in the important infrared wavelengths. △ Less

Submitted 26 January, 2017; originally announced January 2017.

GEMFsim: A Stochastic Simulator for the Generalized Epidemic Modeling Framework

Authors: Faryad Darabi Sahneh, Aram Vajdi, Heman Shakeri, Futing Fan, Caterina Scoglio

Abstract: The recently proposed generalized epidemic modeling framework (GEMF) \cite{sahneh2013generalized} lays the groundwork for systematically constructing a broad spectrum of stochastic spreading processes over complex networks. This article builds an algorithm for exact, continuous-time numerical simulation of GEMF-based processes. Moreover the implementation of this algorithm, GEMFsim, is available i… ▽ More The recently proposed generalized epidemic modeling framework (GEMF) \cite{sahneh2013generalized} lays the groundwork for systematically constructing a broad spectrum of stochastic spreading processes over complex networks. This article builds an algorithm for exact, continuous-time numerical simulation of GEMF-based processes. Moreover the implementation of this algorithm, GEMFsim, is available in popular scientific programming platforms such as MATLAB, R, Python, and C; GEMFsim facilitates simulating stochastic spreading models that fit in GEMF framework. Using these simulations one can examine the accuracy of mean-field-type approximations that are commonly used for analytical study of spreading processes on complex networks. △ Less

Submitted 7 April, 2016; originally announced April 2016.

Biomechanical conditions of walking

Authors: Y. F. Fan, L. P. Luo, Z. Y. Li, S. Y. Han, C. S. Lv, B. Zhang

Abstract: The development of rehabilitation training program for lower limb injury does not usually include gait pattern design. This paper introduced a gait pattern design by using equations (conditions of walking). Following the requirements of reducing force to the injured side to avoid further injury, we developed a lower limb gait pattern to shorten the stride length so as to reduce walking speed, to d… ▽ More The development of rehabilitation training program for lower limb injury does not usually include gait pattern design. This paper introduced a gait pattern design by using equations (conditions of walking). Following the requirements of reducing force to the injured side to avoid further injury, we developed a lower limb gait pattern to shorten the stride length so as to reduce walking speed, to delay the stance phase of the uninjured side and to reduce step length of the uninjured side. This gait pattern was then verified by the practice of a rehabilitation training of an Achilles tendon rupture patient, whose two-year rehabilitation training (with 24 tests) has proven that this pattern worked as intended. This indicates that rehabilitation training program for lower limb injury can rest on biomechanical conditions of walking based on experimental evidence. △ Less

Submitted 2 September, 2015; v1 submitted 14 August, 2015; originally announced August 2015.

Comments: 6 pages, 4 figures

Indirect-direct hybrid-drive work-dominated hotspot ignition for inertial confinement fusion

Authors: X. T. He, Z. F. Fan, J. W. Li, J. Liu, K. Lan, J. F. Wu, L. F. Wang, W. H. Ye

Abstract: An indirect-direct hybrid-drive work-dominated hotspot ignition scheme for inertial confinement fusion is proposed: a layered fuel capsule inside a spherical hohlraum with an octahedral symmetry is compressed first by indirect-drive soft-x rays (radiation) and then by direct-drive lasers in last pulse duration. In this scheme, an enhanced shock and a follow-up compression wave for ignition with pr… ▽ More An indirect-direct hybrid-drive work-dominated hotspot ignition scheme for inertial confinement fusion is proposed: a layered fuel capsule inside a spherical hohlraum with an octahedral symmetry is compressed first by indirect-drive soft-x rays (radiation) and then by direct-drive lasers in last pulse duration. In this scheme, an enhanced shock and a follow-up compression wave for ignition with pressure far greater than the radiation ablation pressure are driven by the direct-drive lasers, and provide large pdV work to the hotspot to perform the work-dominated ignition. The numerical simulations show that the enhanced shock stops the reflections of indirect-drive shock at the main fuel-hotspot interface, and therefore significantly suppresses the hydrodynamic instabilities and asymmetry. Based on the indirect-drive implosion dynamics the hotspot is further compressed and heated by the enhanced shock and follow-up compression wave, resulting in the work-dominated hotspot ignition and burn with a maximal implosion velocity of ~400 km/s and a lower convergence ratio of ~25. The fusion yield of 15 MJ using total laser energy of 1.32 MJ is achieved. △ Less

Submitted 31 March, 2015; originally announced March 2015.

Comments: 14 pages, 5 figures

Ultrasmall Au10-12(SG)10-12 Nanomolecules for High Tumor Specificity and Cancer Radiotherapy

Authors: Xiao-Dong Zhang, Zhentao Luo, Jie Chen, Xiu Shen, Shasha Song, Yuanming Sun, Saijun Fan, Feiyue Fan, David Tai Leong, Jianping Xie

Abstract: Radiosensitizers can increase the local treatment efficacy under a relatively low and safe radiation dose, thereby facilitating tumor eradication and minimizing side effects. Here, we report a new class of radiosensitizers that contain several gold (Au) atoms embedded inside a peptide shell (e.g., Au10-12(SG)10-12) and can achieve ultrahigh tumor uptake (10.86 SUV at 24 h post injection) and targe… ▽ More Radiosensitizers can increase the local treatment efficacy under a relatively low and safe radiation dose, thereby facilitating tumor eradication and minimizing side effects. Here, we report a new class of radiosensitizers that contain several gold (Au) atoms embedded inside a peptide shell (e.g., Au10-12(SG)10-12) and can achieve ultrahigh tumor uptake (10.86 SUV at 24 h post injection) and targeting specificity, efficient renal clearance, and high radiotherapy enhancement. △ Less

Submitted 12 May, 2014; originally announced May 2014.

Comments: 21 pages, 11 figures

Journal ref: Advanced Materials 2014

Metabolizable Bi2Se3 Nanoplates: Biodistribution, Toxicity, and Uses for Cancer Radiation Therapy and Imaging

Authors: Xiao-Dong Zhang, Jie Chen, Yuho Min, Gyeong Bae Park, Xiu Shen, Sha-Sha Song, Yuan-Ming Sun, Hao Wang, Wei Long, Jianping Xie, Kai Gao, Lianfeng Zhang, Saijun Fan, Feiyue Fan, Unyong Jeong

Abstract: Bi, a high atom number element, has a high photoelectric absorption coefficient, and Se element has anticancer activity. Hence, their compound chalcogenide (Bi2Se3) deserves a thorough investigation for biomedical applications. This study reveals that Bi2Se3 nanoplates (54 nm wide) protected with poly(vinylpyrollidone) (PVP) are biocompatible and have low toxicity even at a high dose of 20 mg/kg i… ▽ More Bi, a high atom number element, has a high photoelectric absorption coefficient, and Se element has anticancer activity. Hence, their compound chalcogenide (Bi2Se3) deserves a thorough investigation for biomedical applications. This study reveals that Bi2Se3 nanoplates (54 nm wide) protected with poly(vinylpyrollidone) (PVP) are biocompatible and have low toxicity even at a high dose of 20 mg/kg in mice. This conclusion was made through the studies on the biodistribution and 90-day long term in vivo clearance of the nanoplates. Liver and spleen were dominant organs for the nanoplates accumulation which was mainly due to RES absorption, but 93 % the nanoplates were cleared after 90 days treatment. Concentrations of Bi and Se in tumor tissue continuously increased until 72 h after intraperitoneal injection into mice. Such selective accumulation of Bi was utilized to enhance the contrast of X-ray CT images. The Bi elements concentrated in a tumor led to damage on the tumor cells when exposed to gamma radiation. Growth of the tumor significantly delayed and stopped after 16 days after the tumor was treated with the Bi2Se3 nanoplates and radiation. This work clearly shows that the Bi2Se3 nanoplates may be used for cancer radiation therapy and CT imaging. They deserve further studies for biological and medical applications. △ Less

Submitted 6 December, 2013; originally announced December 2013.

Comments: 32 pages, 12 figures. Advanced Functional Materials, 2014

Enhanced Tumor Accumulation of Sub-2 nm Gold Nanoclusters for Cancer Radiation Therapy

Authors: Xiao-Dong Zhang, Jie Chen, Zhentao Luo, Di Wu, Xiu Shen, Sha-Sha Song, Yuan-Ming Sun, Pei-Xun Liu, Jing Zhao, Shuaidong Huo, Saijun Fan, Feiyue Fan, Xing-Jie Liang, Jianping Xie

Abstract: A new type of metabolizable and efficient radiosensitizer for cancer radiotherapy is presented in this study by combining ultrasmall Au nanoclusters (NCs, <2 nm) with biocompatible coating ligands (glutathione, GSH). The new nano-construct (GSH-coated Au25 NCs) inherits attractive features of both the Au core (strong radiosensitizing effect) and GSH shell (good biocompatibility). It can preferenti… ▽ More A new type of metabolizable and efficient radiosensitizer for cancer radiotherapy is presented in this study by combining ultrasmall Au nanoclusters (NCs, <2 nm) with biocompatible coating ligands (glutathione, GSH). The new nano-construct (GSH-coated Au25 NCs) inherits attractive features of both the Au core (strong radiosensitizing effect) and GSH shell (good biocompatibility). It can preferentially accumulate in tumor via the improved EPR effect, which leads to strong enhancement for cancer radiotherapy. After the treatment, the small-sized GSH-Au25 NCs can be efficiently cleared by the kidney, minimizing any potential side effects due to the accumulation of Au25 NCs in the body. △ Less

Submitted 30 August, 2013; originally announced August 2013.

Comments: 27 pages,10 figures Advanced Healthcare Materials(2014)

In Vivo Renal Clearance, Biodistribution, Toxicity of Gold nanoclusters

Authors: Xiao-Dong Zhang, Di Wu, Xiu Shen, Pei-Xun Liu, Fei-Yue Fan, Sai-Jun Fan

Abstract: Gold nanoparticles have shown great prospective in cancer diagnosis and therapy, but they can not be metabolized and prefer to accumulate in liver and spleen due to their large size. The gold nanoclusters with small size can penetrate kidney tissue and have promise to decrease in vivo toxicity by renal clearance. In this work, we explore the in vivo renal clearance, biodistribution, and toxicity r… ▽ More Gold nanoparticles have shown great prospective in cancer diagnosis and therapy, but they can not be metabolized and prefer to accumulate in liver and spleen due to their large size. The gold nanoclusters with small size can penetrate kidney tissue and have promise to decrease in vivo toxicity by renal clearance. In this work, we explore the in vivo renal clearance, biodistribution, and toxicity responses of the BSA- and GSH-protected gold nanoclusters for 24 hours and 28 days. The BSA-protected gold nanoclusters have low-efficient renal clearance and only 1% of gold can be cleared, but the GSH-protected gold nanoclusters have high-efficient renal clearance and 36 % of gold can be cleared after 24 hours. The biodistribution further reveals that 94% of gold can be metabolized for the GSH-protected nanoclusters, but only less than 5% of gold can be metabolized for the BSA-protected nanoclusters after 28 days. Both of the GSH- and BSA-protected gold nanoclusters cause acute infection, inflammation, and kidney function damage after 24 hours, but these toxicity responses for the GSH-protected gold nanoclusters can be eliminated after 28 days. Immune system can also be affected by the two kinds of gold nanoclusters, but the immune response for the GSH-protected gold nanoclusters can also be recovered after 28 days. These findings show that the GSH-protected gold nanoclusters have small size and can be metabolized by renal clearance and thus the toxicity can be significantly decreased. The BSA- protected gold nanoclusters, however, can form large compounds and further accumulate in liver and spleen which can cause irreparable toxicity response. Therefore, the GSH-protected gold nanoclusters have great potential for in vivo imaging and therapy, and the BSA-protected gold nanoclusters can be used as the agent of liver cancer therapy. △ Less

Submitted 27 September, 2012; originally announced October 2012.

Comments: 12 pages, 8 figures

MSC Class: 92C05 ACM Class: J.3

Journal ref: Zhang et al,Biomaterials 33 (2012) 4628e4638

Highly birefringent polymer terahertz fiber with honeycomb cladding

Authors: Yu Hou, Fei Fan, Zi-Wei Jiang, Xiang-Hui Wang, Sheng-jiang Chang

Abstract: Two highly birefringent polymer terahertz (THz) fibers were proposed in this paper, which were formed with honeycomb cladding and some elliptical air holes in the fiber core. The losses and mode birefringence for two different fibers are investigated by finite-different time-domain method. The results show that fiber 2 can achieve both high birefringence (larger than 0.022) and low confinement los… ▽ More Two highly birefringent polymer terahertz (THz) fibers were proposed in this paper, which were formed with honeycomb cladding and some elliptical air holes in the fiber core. The losses and mode birefringence for two different fibers are investigated by finite-different time-domain method. The results show that fiber 2 can achieve both high birefringence (larger than 0.022) and low confinement loss (0.01 dB/m) in a wide THz frequency range. Moreover, compared with a round solid-core fiber, guiding loss of the THz fiber caused by polymer material absorption can be reduced effectively as a part of the mode power is trapped in the air holes. △ Less

Submitted 4 November, 2011; originally announced November 2011.