A Broadband Dual-polarized Capped Bow-tie 2 72 Antenna Array for 28 GHz Band in 5G Systems

With the development of the fifth generation (5G) communications, dual-polarization base station antennas have increasingly attracted a lot of attention. In this paper, a broadband high-gain efficiency dual-polarization polarized capped bow-tie antenna with parasitic directorsarray is presented. Simulation results show that the bandwidth of the proposed antenna is 24-36.8 GHz, with its return loss better than 10 dB and the stable coverage. The directivities vary from 8 to 12dBi and the relative cross-polar level is below -10dB over the most of band. It has a simple and compact structure, and is ready to be extended for an large array antennas with massive MIMO performance used in 5G communications

A Broadband Dual-polarized Capped Bow-tie 2x2 Antenna Array for 28 GHz Band in 5G Systems

With the development of the fifth generation (5G) communications, dual-polarization base station antennas have increasingly attracted a lot of attention. In this paper, a broadband high-efficiency dual-polarized capped bow-tie antenna array is presented. Simulation results show that the bandwidth of the proposed antenna is 24-36.8 GHz, with its return loss better than 10 dB and the stable coverage. The directivities vary from 8 to 12dBi and the relative cross-polar level is below -10dB over the most of band. It has a simple and compact structure, and is ready to be extended for large array antennas with massive MIMO performance used in 5G communications

Inter-Particle Electronic and Ionic Modifications of the Ternary Ni-Co-Mn Oxide for Efficient and Stable Lithium Storage

A combined electronic and ionic interparticular modification strategy is designed for the improvement of lithium storage in the layer structured ternary Ni-Co-Mn oxide (LiNi0.6Co0.2Mn0.2O2) in the form of spherical particles. In this design, a thin layer of the ion conducting polypropylene carbonate is applied to wrap the individual oxide particles for three purposes: (1) prevention of direct stacking and packing between oxide particles that will otherwise impede or block ions from accessing all the surface of the oxide particles, (2) provision of additional ionic pathways between the oxide particles, and (3) stabilization of the oxide particles during lithium storage and release. The design includes also the use of nitrogen doped carbon nanotubes for electronic connection between the polymer coated individual spheres of the layered nickel-rich LiNi0.6Co0.2Mn0.2O2. According to the physicochemical and electrochemical characterizations, and laboratory battery tests, it can be concluded that the LiNi0.6Co0.2Mn0.2O2 composite has a unique porous structure that is assembled by the polymer coated ternary oxide microspheres and the nitrogen-doped carbon nanotube networks. Significant improvements are achieved in both the ionic and electronic conductivities (double or more increase), and in discharge specific capacity (201.3 mAh·g−1 at 0.1 C, improved by 13.28% compared to the non-modified LiNi0.6Co0.2Mn0.2O2), rate performance and cycling stability (94.40% in capacity retention after 300 cycles at 1.0 C)

Deep Coupled Integration of CSAC and GNSS for Robust PNT

Global navigation satellite systems (GNSS) are the most widely used positioning, navigation, and timing (PNT) technology. However, a GNSS cannot provide effective PNT services in physical blocks, such as in a natural canyon, canyon city, underground, underwater, and indoors. With the development of micro-electromechanical system (MEMS) technology, the chip scale atomic clock (CSAC) gradually matures, and performance is constantly improved. A deep coupled integration of CSAC and GNSS is explored in this thesis to enhance PNT robustness. “Clock coasting” of CSAC provides time synchronized with GNSS and optimizes navigation equations. However, errors of clock coasting increase over time and can be corrected by GNSS time, which is stable but noisy. In this paper, weighted linear optimal estimation algorithm is used for CSAC-aided GNSS, while Kalman filter is used for GNSS-corrected CSAC. Simulations of the model are conducted, and field tests are carried out. Dilution of precision can be improved by integration. Integration is more accurate than traditional GNSS. When only three satellites are visible, the integration still works, whereas the traditional method fails. The deep coupled integration of CSAC and GNSS can improve the accuracy, reliability, and availability of PNT

Role of lymph node dissection in the management of upper tract urothelial carcinomas: a meta-analysis

Abstract Background Lymph node dissection (LND) is not routinely performed during radical nephroureterectomy (RNU) in upper tract urothelial carcinomas (UTUC) and the role of LND has been controversial. We aim to investigate whether patients with LND had improved survival in UTUC patients. Methods We performed a systematic literature search of PubMed, Embase, and Cochrane library for citations published prior to January 2016, describing LND performed among UTUC patients and conducted a standard meta-analysis of survival outcomes. Results Eleven eligible studies containing 7516 patients satisfied the inclusion criteria. Pooled HRs for cancer-specific survival (CSS) and recurrence-free survival (RFS) were 1.17 (P = 0.18) and 1.33 (P = 0.19) respectively. However, the patients in the LND group had more advanced tumour stages and grades (P < 0.001). Further subgroup analysis showed that among muscle-invasive UTUC patients, the pooled HR for CSS and RFS were 1.10 (P = 0.42) and 0.92 (P = 0.72) respectively. Besides, no difference was found in CSS and RFS between pN0 and pNx individuals in overall populations and in patients with muscle-invasive UTUC, while pN+ patients had significantly worse prognosis when compared to pN0 patients. Conclusions LND during RNU allows more accurate staging and prediction of survival, but it remains uncertain whether LND independently improves survival in patients with UTUC. However, standard use of LND should be further investigated in a multi-center, prospective evaluation to obtain a definitive statement regarding this matter

Enhancing mechanical strength, tribological properties, cytocompatibility, osteogenic differentiation, and antibacterial capacity of biodegradable Zn-5RE (RE = Nd, Y, and Ho) alloys for potential bone-implant application

Degradable zinc (Zn) based metals exhibit great promise as potential load-bearing bone-implant materials due to their suitable biodegradability, good fabricate-friendliness, biocompatibility, and favorable osteogenesis-promoting capacity. Nevertheless, most as-cast Zn-based metals display poor mechanical properties due to their coarse grain size and few slip systems, which is challenging to meet bone-implant application requirements. Herein, the alloying using rare earth (RE) elements of neodymium (Nd), yttrium (Y), and holmium (Ho) combined with hot-rolling was used to prepare the hot-rolled (HR) Zn-5RE binary alloys for load-bearing bone fixation or bone repair applications. HR Zn–5Y sample demonstrated the best mechanical properties matching with an ultimate tensile strength of ∼260 MPa, yield strength of ∼200 MPa, elongation of ∼43.5%, strength-elongation product of ∼11.3 GPa%, and macro-hardness of ∼104.7 HB among the HR samples, close to the requirements of mechanical properties for degradable bone-implant materials. HR Zn–5Y sample exhibited the lowest corrosion rate of ∼178 μm/y measured by electrochemical polarization testing, the degradation rate of ∼29 μm/y measured by static immersion testing, and high tribological properties in Hanks’ solution. The diluted Zn–5Y extract showed an appropriate cytocompatibility to 3T3 and MG-63 cells and moderate osteogenic differentiation ability to 3T3 cells among HR Zn-5RE and pure Zn extracts. Meanwhile, the HR Zn–5Y sample showed a suitable and effective antibacterial capacity against S. aureus and E. coli. Overall, the HR Zn–5Y sample is a promising moderate load-bearing bone-implant material for bone pins, plates, and guiding bone regeneration membrane application

Responsive fluorescent Bi2O3@PVA hybrid nanogels for temperature-sensing, dual-modal imaging, and drug delivery

The polymer-inorganic hybrid nanogels with temperature-responsive characteristic are of considerable current interest to many fields ranging from fundamental biomaterials science to bionanomedicine. This paper reports the preparation of temperature-responsive hybrid nanogels by immobilization of Bi2O3 quantum dots (QDs) in the interior of a nanogel of poly(vinyl alcohol) (PVA). Unlike conventional temperature-responsive hybrid nanogels with the responsive features deriving from the temperature-responsive polymers (e.g. PNIPAMs or non-linear PEGs), we demonstrate that QDs can work cooperatively with the gel networks of PVA, an unconventional responsive polymer, to enable the temperature-induced volume phase transition of the designed Bi2O3@PVA hybrid nanogels. Building on the rationales, Bi2O3@PVA hybrid nanogels can adapt to a surrounding fluids of different temperatures over the physiologically important range of 37-40 degrees C, convert the disruptions in homeostasis of environmental temperature into high-sensitive fluorescent signals, enter into the mouse melanoma B16F10 cells for dark-field and fluorescence dual-modal imaging, and regulate the release of a model anticancer drug temozolomide. The unconventional strategy that can broaden the design scheme of temperature-responsive hybrid nanogels for theranostic action should enhance our ability to address the complexity of biological systems. (C) 2012 Elsevier Ltd. All rights reserved.Xiamen University (China); NFFTBS (China) [J1030415]; US Agency for International Development, USA [PGA-P280422

An in situ Zn–5Mg2Ge composite processed by ultrasonication for biodegradable orthopedic implant applications

Zinc (Zn)-based composites have been received adequate attention lately in the biomedical field as degradable biomaterials owing to their simple preparation process, inherent biodegradability, intrinsic biological activity, and good biocompatibility. Nevertheless, the low mechanical strength and fast corrosion rate of Zn-based composites caused by a large number of coarse reinforcement particles have severely impeded their further clinical application. This work reports a promising method to fabricate an in situ biodegradable Zn–5Mg2Ge composite with high mechanical properties, wear resistance, corrosion resistance, and cytocompatibility via high-intensity ultrasonication and followed by hot-rolling. After hot rolling, the ultrasonicated Zn–5Mg2Ge composite exhibited the best mechanical properties and hardness with a yield strength, an ultimate tensile strength, elongation, Vickers hardness, and Brinell hardness of 142.9 MPa, 253.6 MPa, 8.9%, 109.5 HV, and 104.0 HB, respectively. Further, the ultrasonicated Zn–5Mg2Ge composite after hot-rolling exhibited significantly higher corrosion and wear resistance than its un-ultrasonicated counterpart in Hanks’ solution. The diluted extract (12.5% concentration) of the

Dramatic increase in reactive volatile organic compound (VOC) emissions from ships at berth after implementing the fuel switch policy in the Pearl River Delta Emission Control Area

Limiting fuel sulfur content (FSC) is a widely adopted approach for reducing ship emissions of sulfur dioxide (SO2) and particulate matter (PM), particularly in emission control areas (ECAs), but its impact on the emissions of volatile organic compounds (VOCs) is still not well understood. In this study, emissions from ships at berth in Guangzhou, southern China, were characterized before and after the implementation of the fuel switch policy (IFSP) with an FSC limit of 0.5% in the Pearl River Delta ECA (ECA-PRD). After IFSP, the emission factors (EFs) of SO2 and PM2.5 for the coastal vessels decreased by 78% and 56% on average, respectively; however, the EFs of the VOCs were 1807 +/- 1746 mg kg(-1), approximately 15 times that of 118 +/- 56.1 mg kg(-1) before IFSP. This dramatic increase in the emissions of the VOCs might have been largely due to the replacement of high-sulfur residual fuel oil with low-sulfur diesel or heavy oils, which are typically richer in short-chain hydrocarbons. Moreover, reactive alkenes surpassed alkanes to become the dominant group among the VOCs, and low-carbon-number VOCs, such as ethylene, propene and isobutane, became the dominant species after IFSP. As a result of the largely elevated EFs of the reactive alkenes and aromatics after IFSP, the emitted VOCs per kilogram of fuel burned had nearly 29 times greater ozone formation potential (OFP) and approximately 2 times greater secondary organic aerosol formation potential (SOAFP) than those before IFSP. Unlike the coastal vessels, the river vessels in the region used diesel fuels consistently and were not affected by the fuel switch policy, but the EFs of their VOCs were 90% greater than those of the coastal vessels after IFSP, with approximately 120% greater fuel-based OFP and 70 %-140% greater SOAFP. The results from this study suggest that while the fuel switch policy could effectively reduce SO2 and PM emissions, and thus help control PM2.5 pollution, it will also lead to greater emissions of reactive VOCs, which may threaten ozone pollution control in harbor cities. This change for coastal or ocean-going vessels, in addition to the large amounts of reactive VOCs from the river vessels, raises regulatory concerns for ship emissions of reactive VOCs