Bis­(chloro­acetato-κO)bis(trimethyl­silylmethyl)tin(IV)

In the title complex, [Sn(C2H2ClO2)2(C4H11Si)2], the SnIV ion is coordinated in a distorted tetra­hedral environment formed by two O atoms from two monodenate chloro­acetato ligands and two C atoms from two trimethyl silyl ligands. Two further weak intra­molecular Sn⋯O contacts [2.744 (2) and 2.655 (2) Å] are formed by the chloro­acetato ligands

6,6′-Di-tert-butyl-4,4′-dimethyl-2,2′-[1,2-phenyl­enebis(nitrilo­methanylyl­idene)]diphenol

In the title mol­ecule, C30H36N2O2, the dihedral angles between the central benzene ring and the two benzene rings of the butyl­salicylaldimine groups are 14.3 (2) and 40.6 (2)°. There are two strong intra­molecular O—H⋯N hydrogen bonds which form S(6) rings. The crystal studied was a non-merohedral twin with refined components of 0.270 (4) and 0.730 (4)

A survey of multi-access edge computing in 5G and beyond : fundamentals, technology integration, and state-of-the-art

Driven by the emergence of new compute-intensive applications and the vision of the Internet of Things (IoT), it is foreseen that the emerging 5G network will face an unprecedented increase in traffic volume and computation demands. However, end users mostly have limited storage capacities and finite processing capabilities, thus how to run compute-intensive applications on resource-constrained users has recently become a natural concern. Mobile edge computing (MEC), a key technology in the emerging fifth generation (5G) network, can optimize mobile resources by hosting compute-intensive applications, process large data before sending to the cloud, provide the cloud-computing capabilities within the radio access network (RAN) in close proximity to mobile users, and offer context-aware services with the help of RAN information. Therefore, MEC enables a wide variety of applications, where the real-time response is strictly required, e.g., driverless vehicles, augmented reality, robotics, and immerse media. Indeed, the paradigm shift from 4G to 5G could become a reality with the advent of new technological concepts. The successful realization of MEC in the 5G network is still in its infancy and demands for constant efforts from both academic and industry communities. In this survey, we first provide a holistic overview of MEC technology and its potential use cases and applications. Then, we outline up-to-date researches on the integration of MEC with the new technologies that will be deployed in 5G and beyond. We also summarize testbeds and experimental evaluations, and open source activities, for edge computing. We further summarize lessons learned from state-of-the-art research works as well as discuss challenges and potential future directions for MEC research

Prognostic implications of plasma fibrinogen and serum Creactive protein levels in non-small cell lung cancer resection and survival

Purpose: To investigate the prognostic implications of plasma fibrinogen and serum C-reactive protein (CRP) levels in tumour resection and survival following successful tumour resection in patients with nonsmall cell lung cancer (NSCLC).Methods: One hundred and fifty-three NSCLC patients who underwent surgical resection at a tertiary care hospital from January 2006 through December 2010 were enrolled. Pre-operative serum CRP and plasma fibrinogen levels were  measured. The levels of these biomarkers correlated with tumour size and pathologic TNM stage. The possibility of complete resection and associated findings are reported.Results: Plasma fibrinogen (r = 0.381, p = 0.002) and serum CRP (r = 0.471, p < 0.001) levels were positively associated with tumour diameter. Increased levels of these biomarkers were significantly associated with sex, smoking status, histological type, tumour stage, and clinical stage. Partial tumour resection occurred in 28 % (27/95) of patients with an increased plasma fibrinogen level compared to 10 % (6/58) with a normal fibrinogen level (p = 0.008), and in 30 % (29/97) of patients with an increased serum CRP level compared to 11 % (6/56) with a normal CRP level (p = 0.006). Patients with elevated CRP and fibrinogen concentrations demonstrated higher susceptibility to disease advancement andsurvival compared to patients with normal fibrinogen and CRP levels.Conclusion: Pre-operative functional concentrations of serum CRP and plasma fibrinogen could serve as indicators of tumour resectability wherein a high tumour resection rate is possible in patients with favourable pre-operative levels of these biomarkers. Increased concentrations of serum CRP and plasma fibrinogen are associated with poor overall survival and progression-free survival.Key words: Plasma fibrinogen, serum C-reactive protein, biomarker, non-small cell lung cance

Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors

Cuprates, ferropnictides and ferrochalcogenides are three classes of unconventional high-temperature superconductors, who share similar phase diagrams in which superconductivity develops after a magnetic order is suppressed, suggesting a strong interplay between superconductivity and magnetism, although the exact picture of this interplay remains elusive. Here we show that there is a direct bridge connecting antiferromagnetic exchange interactions determined in the parent compounds of these materials to the superconducting gap functions observed in the corresponding superconducting materials. High superconducting transition temperature is achieved when the Fermi surface topology matches the form factor of the pairing symmetry favored by local magnetic exchange interactions. Our result offers a principle guide to search for new high temperature superconductors.Comment: 12 pages, 5 figures, 1 table, 1 supplementary materia

Three-dimensional measurement of object surfaces with complex shape and color distribution based on projection of color fringe patterns

A challenging issue associated with three-dimensional (3D) fringe patterns profilometry (FPP) is the unwrapping of phase maps resulting from color object surfaces. This paper proposes a new colorprojection-based 3D FPP, making use of the three primary color channels [i.e., red, green, and blue (RGB)] associated with digital projectors. One channel (e.g., red) is used for projecting sinusoidal fringes required by phase shift profilometry (PSP); the other two channels are employed for generating binary stripe patterns. In order to achieve reliable phase unwrapping, each fringe of the sinusoidal patterns is identified by a unique binary sequence. These sequences are then encoded by a channel-encoding scheme used in the area of communication. The encoded sequences are embedded in the binary coding stripe images, which are projected together with the sinusoidal patterns. The three image patterns are reflected by the object surface and captured by an RGB 3-CCD camera. The reflected sinusoidal patterns are employed to yield a wrapped phase map, and the binary stripe patterns are used to retrieve the encoded sequences, which are then decoded to yield the original binary sequences for phase unwrapping. Compared with existing color-encoded algorithms, the proposed approach uses binary codes instead of fringe color to identify the fringes, which are less sensitive to the disturbances caused by object surface color and illumination noises. Furthermore, use of the channel-coding scheme provides extra resistance to the disturbances caused by object surface color and illumination noises. Experimental results are presented to confirm the effectiveness of the proposed technique

Effective electro-optical modulation with high extinction ratio by a graphene-silicon microring resonator

Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultra-large absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of Fermi level enables electro-optical modulation, optical-optical switching, and other optoelectronics applications. However, achieving a high modulation depth remains a challenge because of the modest graphene-light interaction in the graphene-silicon devices, typically, utilizing only a monolayer or few layers of graphene. Here, we comprehensively study the interaction between graphene and a microring resonator, and its influence on the optical modulation depth. We demonstrate graphene-silicon microring devices showing a high modulation depth of 12.5 dB with a relatively low bias voltage of 8.8 V. On-off electro-optical switching with an extinction ratio of 3.8 dB is successfully demonstrated by applying a square-waveform with a 4 V peak-to-peak voltage.Comment: 12 pages, including 7 figure

Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor

Alkali-doped iron selenide is the latest member of high Tc superconductor family, and its peculiar characters have immediately attracted extensive attention. We prepared high-quality potassium-doped iron selenide (KxFe2-ySe2) thin films by molecular beam epitaxy and unambiguously demonstrated the existence of phase separation, which is currently under debate, in this material using scanning tunneling microscopy and spectroscopy. The stoichiometric superconducting phase KFe2Se2 contains no iron vacancies, while the insulating phase has a \surd5\times\surd5 vacancy order. The iron vacancies are shown always destructive to superconductivity in KFe2Se2. Our study on the subgap bound states induced by the iron vacancies further reveals a magnetically-related bipartite order in the superconducting phase. These findings not only solve the existing controversies in the atomic and electronic structures in KxFe2-ySe2, but also provide valuable information on understanding the superconductivity and its interplay with magnetism in iron-based superconductors