Design of a Compact Monopole Antenna for UWB Applications

In this paper, a low cost, highly efficient and low profile monopole antenna for ultra-wideband (UWB) applications is presented. A new inverted triangular-shape structure possessing meander lines is designed to achieve a wideband response and high efficiency. To design the proposed structure, three steps are utilized to achieve an UWB response. The bandwidth of the proposed antenna is improved with changing meander lines parameters, miniaturization of the ground width and optimization of the feeding line. The measured and simulated frequency band ranges from 3.2 to 12 GHz, while the radiation patterns are measured at 4, 5.3, 6 and 8 GHz frequency bands. The overall volume of the proposed antenna is 26 × 25 × 1.6 mm3 ; whereas the FR4 material is used as a substrate with a relative permittivity and loss tangent of 4.3 and 0.025, correspondingly. The peak gain of 4 dB is achieved with a radiation efficiency of 80 to 98% for the entire wideband. Design modelling of proposed antenna is performed in ANSYS HFSS 13 software. A decent consistency between the simulated and measured results is accomplished which shows that the proposed antenna is a potential candidate for the UWB applications.     

Vivaldi Antennas for Microwave Imaging: Theoretical Analysis and Design Considerations

The geometrical and electrical features of the Vivaldi antenna are studied in the light of the frequency-independent antenna theory. A scaling principle is derived for the exponential tapering of the antenna, and a closed-form model for the current distribution is provided. Such theoretical results are in good agreement with several numerical simulations performed by using the NEC2 code. Furthermore, a practical feeding system, based on a double-Y balun, is developed and tested to obtain a more systematic approach to the design of the aforesaid antennas     

A Constant Gain and Miniaturized Antipodal Vivaldi Antenna for 5G Communication Applications

This paper proposes a stable gain and a compact Antipodal Vivaldi Antenna (AVA) for a 38 GHz band of 5G communication. A novel compact AVA is designed to provide constant gain, high front to back ratio (FBR), and very high efficiency. The performance of the proposed AVA is enhanced with the help of a dielectric lens (DL) and corrugations. A rectangular-shaped DL is incorporated in conventional AVA (CAVA) to enhance its gain up to 1 dBi and the bandwidth by 1.8 GHz. Next, the rectangular corrugations are implemented in CAVA with lens (CAVA-L) to further improve the gain and bandwidth. The proposed AVA with lens and corrugations (AVA-LC) gives a constant and high gain of 8.2 to 9 dBi. The designed AVA-LC operates from 34 to 45 GHz frequency which covers 38 GHz (37.5 to 43.5 GHz) band of 5G applications. Further, the presented AVA-LC mitigates the back lobe and sidelobe levels, resulting in FBR and efficiency improvement. The FBR is in the range of 12.2  to 22 dB, and efficiency is 99%, almost constant. The AVA-LC is fabricated on Roger’s RT/duroid 5880 substrate, and it is tested to verify the simulated results. The proposed compact AVA-LC with high gain, an improved FBR, excellent efficiency, and stable radiation patterns is suitable for the 38 GHz band of 5G devices.     

Biophysical Phenotyping and Modulation of ALDH+ Inflammatory Breast Cancer Stem‐Like Cells

Cancer stem‐like cells (CSCs) have been shown to initiate tumorigenesis and cancer metastasis in many cancer types. Although identification of CSCs through specific marker expression helps define the CSC compartment, it does not directly provide information on how or why this cancer cell subpopulation is more metastatic or tumorigenic. In this study, the functional and biophysical characteristics of aggressive and lethal inflammatory breast cancer (IBC) CSCs at the single‐cell level are comprehensively profiled using multiple microengineered tools. Distinct functional (cell migration, growth, adhesion, invasion and self‐renewal) and biophysical (cell deformability, adhesion strength and contractility) properties of ALDH+ SUM149 IBC CSCs are found as compared to their ALDH? non‐CSC counterpart, providing biophysical insights into why CSCs has an enhanced propensity to metastasize. It is further shown that the cellular biophysical phenotype can predict and determine IBC cells' tumorigenic ability. SUM149 and SUM159 IBC cells selected and modulated through biophysical attributes—adhesion and stiffness—show characteristics of CSCs in vitro and enhance tumorigenicity in in vivo murine models of primary tumor growth. Overall, the multiparametric cellular biophysical phenotyping and modulation of IBC CSCs yields a new understanding of IBC's metastatic properties and how they might develop and be targeted for therapeutic interventions.     

基于LTCC宽频带双频差分天线的研究与设计

提出了一种新型宽频带双频差分天线.该天线基于低温共烧陶瓷(Low Temperature Co-Fired Ceramies,简称LTCC)技术,采用矩形环状贴片,并使用两条叉形微带馈线进行差分馈电,是一种具有平衡结构的宽缝隙天线,该结构使得天线拥有很宽的频带宽度.天线两频段的中心频率为2.63 GHz和5.13 GH...     

激光探测告警光学系统设计

为满足激光探测告警光学系统对大视场和光学增益的要求,提出了宽视场有增益光学系统。该系统工作波长范围1.06~1.54μm,全视场角60°,最大口径28mm,PIN光电探测器光敏面直径2mm。物镜采用二片式反远距结构,增大了视场和后工作距离。弯月型负透镜在前,具有平衡像差和棱镜的偏向作用;物镜后放置高折射率标准超半球型浸没透镜,满足小光敏面探测器接收。分析结果表明,系统像高0.99mm,光学增益达15.33,结构简单,可有效降低激光辐射源功率、增强探测距离。     

Construction of pH-Sensitive Nanovaccines Encapsulating Tumor Cell Lysates and Immune Adjuvants for Breast Cancer Therapy

The current immunotherapy strategies for triple negative breast cancer (TNBC) are greatly limited due to the immunosuppressive tumor microenvironment (TME). Immunization with cancer vaccines composed of tumor cell lysates (TCL) can induce an effective antitumor immune response. However, this approach also has the disadvantages of inefficient antigen delivery to the tumor tissues and the limited immune response elicited by single-antigen vaccines. To overcome these limitations, a pH-sensitive nanocalcium carbonate (CaCO₃) carrier loaded with TCL and immune adjuvant CpG (CpG oligodeoxynucleotide 1826) is herein constructed for TNBC immunotherapy. This tailor-made nanovaccine, termed CaCO₃@TCL/CpG, not only neutralizes the acidic TME through the consumption of lactate by CaCO₃, which increases the proportion of the M1/M2 macrophages and promotes infiltration of effector immune cells but also activates the dendritic cells in the tumor tissues and recruits cytotoxic T cells to further kill the tumor cells. In vivo fluorescence imaging study shows that the pegylated nanovaccine could stay longer in the blood circulation and extravasate preferentially into tumor site. Besides, the nanovaccine exhibits high cytotoxicity in 4T1 cells and significantly inhibits tumor growth of tumor-bearing mice. Overall, this pH-sensitive nanovaccine is a promising nanoplatform for enhanced immunotherapy of TNBC.     

Multi-Targeted and On-Demand Non-Coding RNA Regulation Nanoplatform against Metastasis and Recurrence of Triple-Negative Breast Cancer

Dysregulation of microRNAs (miRs) is the hallmark of triple-negative breast cancer (TNBC), which is closely involved with its growth, metastasis, and recurrence. Dysregulated miRs are promising targets for TNBC therapy, however, targeted and accurate regulation of multiple disordered miRs in tumors is still a great challenge. Here, a multi-targeting and on-demand non-coding RNA regulation nanoplatform (MTOR) is reported to precisely regulate disordered miRs, leading to dramatical suppression of TNBC growth, metastasis, and recurrence. With the assistance of long blood circulation, ligands of urokinase-type plasminogen activator peptide and hyaluronan located in multi-functional shells enable MTOR to actively target TNBC cells and breast cancer stem cell-like cells (BrCSCs). After entering TNBC cells and BrCSCs, MTOR is subjected to lysosomal hyaluronidase-induced shell detachment, leading to an explosion of the TAT-enriched core, thereby enhancing nuclear targeting. Subsequently, MTOR could precisely and simultaneously downregulate microRNA-21 expression and upregulate microRNA-205 expression in TNBC. In subcutaneous xenograft, orthotopic xenograft, pulmonary metastasis, and recurrence TNBC mouse models, MTOR shows remarkably synergetic effects on the inhibition of tumor growth, metastasis, and recurrence due to its on-demand regulation of disordered miRs. This MTOR system opens a new avenue for on-demand regulation of disordered miRs against growth, metastasis, and recurrence of TNBC.     

深孔变壁厚锥形件冷挤压工艺与模具设计

深孔变壁厚锥形件需要3次挤压成形,给出了该零件冷挤压工艺和实用的模具结构,论述了反挤压工序件与成品正挤压模腔的关系,以及凸模和凹模设计.该模具采用伸缩式双级卸料装置,实现较大行程的卸料.     

面向乳腺诊断的时域扩散光学层析图像重建方法

为了克服传统的X射线乳腺成像术在灵敏度、特异性、安全性和舒适性等方面存在的重大缺陷，提出了一种面向乳腺成像的时域扩散光学层析（diffuse optical tomography，DOT）图像重建技术．该技术以拉普拉斯变换时域扩散方程的有限元（finite element method，FEM）数值解作为正向模型，采用基于牛顿-拉夫逊迭代格式的逆模型框架．通过对锥形压缩乳房光学层析模式的模拟实验研究表明，该方法可有效重构出乳腺肿瘤组织的吸收系数μa和约化散射系数μs′的层析图像，且成像目标的空间位置准确，具有较高的图像质量．     

Traceable Bioinspired Nanoparticle for the Treatment of Metastatic Breast Cancer via NIR‐Trigged Intracellular Delivery of Methylene Blue and Cisplatin

Cytotoxic T lymphocyte (CTL) eliminates abnormal cells through target recognition‐triggered intracellular toxin delivery. Chimeric antigen receptor T‐cell improves cancer cell recognition of CTL, but its effectiveness and safety in solid tumor treatment are still hampered by poor tumor infiltration, suppressive tumor microenvironment, and severe on‐target off‐tumor toxicity. Given the functionality and challenges of CTL in cancer therapy, herein, a CTL‐inspired nanovesicle (MPV) with a cell membrane–derived shell and a methylene blue (MB) and cisplatin (Pt) loaded gelatin nanogel core is created. The MPV generates contrast for tumor photoacoustic imaging, and produces hyperthermia upon laser irradiation, enabling photothermal imaging and deep tumor penetration. Meanwhile, it releases MB and Pt, and then delivers them into the cytosol of cancer cells, which process can be visualized by imaging the recovery of MB‐derived fluorescence. The localized hyperthermia, photodynamic therapy, and chemotherapy together kill 4T1 breast cancer cells effectively, resulting in primary tumor regression and 97% inhibition of pulmonary metastasis, without significant toxicity to the animals. Taken together, the MPV shows tumor‐specific and stimuli‐triggered intracellular toxin delivery with advantages in traceable accumulation and activation, high tumor penetration, and triple combination therapy, and thus can be an effective nanomedicine for combating metastatic breast cancer.     

一个用于高温冷藏库及通风空调系统条缝均匀送风管道设计计算的简化公式

本文针对高温冷藏库及空调通风工程中普遍采用的条缝式均匀送风管道截面宽度计算问题，从考虑沿程阻力系数λ值随截面位置x的变化入手，提出了一个较为简便的计算公式，可供有关设计计算人员参考。     

激光微型靶丸位置检测中的图像分析与精度测试

在高功率激光实验装置中,为了实现多路激光精确瞄准到实验靶上,需对实验靶进行高精度定位。根据检测装置需要,建立了一套基于视觉系统的实验靶位置测量模拟系统,从而实现高精度靶瞄准与靶定位检测。本文从利用改进的均值漂移(MeanShift)算法对靶丸图像进行预处理出发,分析光照变化对靶丸中心点检测的影响,并通过相关系数模板匹配方法对靶丸端面中心进行计算分析,利用图像聚焦度分析离焦量对靶丸中心位置检测的影响。实验结果表明,图像检测系统分辨率为0.4μm,最小位移测量精度为1.2μm;当靶面图像离焦量在-10～30μm范围内时,靶丸中心位置的漂移量小于1μm,能够满足靶丸位置检测误差不大于8μm的要求。     

Performance of near-infrared dyes as effective contrast agents for breast cancer detection through simulation of photoacoustic imaging

ABSTRACT

Targeted photoacoustic imaging using exogenous contrast agents can potentially improve early detection of breast cancer, even at significant depths inside the breast. In this study, computer simulations were performed to compare the photoacoustic performance of 11 different near-infrared (NIR) dyes for detecting tumours deep inside the breast tissue. It was observed that the three high performing NIR dyes produced at least two-fold contrast enhancement of a spherical breast tumour embedded at 4?cm depth inside the breast than those of the corresponding endogenous contrast agents. These three selected dyes were employed to visualize small blood vessels deep inside the breast tissue. Although methylene blue provided the best contrast in visualizing tumour blood vessels at depths beyond 3?cm, considering other factors such as availability of suitable targeting agent, indocyanine green at 800?nm may be preferred over all other dyes for deep breast imaging applications.     

Integrating Fluorinated Polymer and Manganese‐Layered Double Hydroxide Nanoparticles as pH‐activated 19F MRI Agents for Specific and Sensitive Detection of Breast Cancer

¹⁹F magnetic resonance imaging (¹⁹F MRI) agents capable of being activated upon interactions with cancer triggers are attracting increasing attention, although challenges still remain for precise and specific detection of cancer tissues. In this study, a novel hybrid ¹⁹F MRI agent for pH‐sensitive detection of breast cancer tissues is reported, a composite system designed by conjugating a perfluoropolyether onto the surface of manganese‐incorporated layered double hydroxide (Mn‐LDH@PFPE) nanoparticles. The ¹⁹F NMR/MRI signals from aqueous solutions of Mn‐LDH@PFPE nanoparticles are quenched at pH 7.4, but “turned on” following a reduction in pH to below 6.5. This is due to partial dissolution of Mn²⁺ from the Mn‐LDH nanoparticles and subsequent reduction in the effect of paramagnetic relaxation. Significantly, in vivo experiments reveal that an intense ¹⁹F MR signal can be detected only in the breast tumor tissue after intravenous injection of Mn‐LDH@PFPE nanoparticles due to such a specific activation. Thus pH‐activated Mn‐LDH@PFPE nanoparticles are a potential “smart” ¹⁹F MRI agent for precise and specific detection of cancer diseases.     

A Spontaneous 3D Bone‐On‐a‐Chip for Bone Metastasis Study of Breast Cancer Cells

Bone metastasis occurs at ≈70% frequency in metastatic breast cancer. The mechanisms used by tumors to hijack the skeleton, promote bone metastases, and confer therapeutic resistance are poorly understood. This has led to the development of various bone models to investigate the interactions between cancer cells and host bone marrow cells and related physiological changes. However, it is challenging to perform bone studies due to the difficulty in periodic sampling. Herein, a bone‐on‐a‐chip (BC) is reported for spontaneous growth of a 3D, mineralized, collagenous bone tissue. Mature osteoblastic tissue of up to 85 µm thickness containing heavily mineralized collagen fibers naturally formed in 720 h without the aid of differentiation agents. Moreover, co‐culture of metastatic breast cancer cells is examined with osteoblastic tissues. The new bone‐on‐a‐chip design not only increases experimental throughput by miniaturization, but also maximizes the chances of cancer cell interaction with bone matrix of a concentrated surface area and facilitates easy, frequent observation. As a result, unique hallmarks of breast cancer bone colonization, previously confirmed only in vivo, are observed. The spontaneous 3D BC keeps the promise as a physiologically relevant model for the in vitro study of breast cancer bone metastasis.     

Cooperative Treatment of Metastatic Breast Cancer Using Host–Guest Nanoplatform Coloaded with Docetaxel and siRNA

Conventional chemotherapy shows moderate efficiency against metastatic cancer since it targets only part of the mechanisms regulating tumor growth and metastasis. Here, gold nanorod (GNR)‐based host‐guest nanoplatforms loaded with docetaxel (DTX) and small interfering RNA (siRNA)‐p65 (referred to as DTX‐loaded GNR (GDTX)/p65) for chemo‐, RNA interference (RNAi), and photothermal ablation (PTA) cooperative treatment of metastatic breast cancer are reported. To prepare the nanoplatform, GNRs are first coated with cyclodextrin (CD)‐grafted polyethylenimine (PEI) and then loaded with DTX and siRNA through host–guest interaction with CD and electrostatic interaction with PEI, respectively. Upon near‐infrared laser irradiation, GNRs generate a significant hyperthermia effect to trigger siRNA and DTX release. DTX reduces tumor growth by inhibiting mitosis of cancer cells. Meanwhile, siRNA‐p65 suppresses lung metastasis and proliferation of cancer cells by blocking the nuclear factor kappa B (NF‐κB) pathway and downregulating the downstream genes matrix metalloproteinase‐9 (MMP‐9) and B cell lymphoma‐2 (Bcl‐2). It is demonstrated that GDTX/p65 in combination with laser irradiation significantly inhibits the growth and lung metastasis of 4T1 breast tumors. The antitumor results suggest promising potential of the host–guest nanoplatform for combinational treatment of metastatic cancer by using RNAi, chemotherapy, and PTA.     

Application of macro-bending for flat and broad gain EDFA

Gain flattened C-band erbium-doped fiber amplifier (EDFA) is demonstrated using a macro-bending method. Various bending diameter and length of high concentration aluminosilicate EDFA are theoretically and experimentally analyzed. By varying the bending radius and the length of the doped fiber, the gain saturation effect as well as the energy transfer from shorter wavelength to a longer wavelength can be controlled to obtain a flattened and broadened gain profile in the C-band region. The amplifier uses a 9 m long erbium-doped fiber (EDF) with erbium ion density of 1.6 × 10²⁵ ions m^?3 and bending radius of 6.5 mm as a gain medium. The gain variation of the EDFA is obtained within ±1 dB over 25 nm bandwidth of C-band region.     

Analysis and design of a rib-like-based slot waveguide for nonlinear silicon nanophotonics

Design of efficient nonlinear optical waveguides is an essential requirement for development of silicon nanophotonics. These waveguides should have a unique capability to play the main role in realization of both passive and active optical devices. A high-performance dielectric rib-like-based slot waveguide is proposed for nonlinear silicon nanophotonics. Its slot region can be filled with Si-nc:SiO₂ which exhibits a high third-order nonlinear effect. Study of numerical results shows that this new slot waveguide has a nonlinear parameter of the same order of magnitude as an equally sized silicon nanophotonics strip-based slot waveguide. The new waveguide can be fabricated easily by etching a slot in the core region of the silicon-on-insulator (SOI)-based rib-like waveguide.