Visible-light promoted atom transfer radical addition-elimination (ATRE) reaction for the synthesis of fluoroalkylated alkenes using DMA as electron-donor

Here, we describe a mild, catalyst-free and operationally-simple strategy for the direct fluoroalkylation of olefins driven by the photochemical activity of an electron donor-acceptor (EDA) complex between DMA and fluoroalkyl iodides. The significant advantages of this photochemical transformation are high efficiency, excellent functional group tolerance, and synthetic simplicity, thus providing a facile route for further application in pharmaceuticals and life sciences

Filtering antenna with two-octave harmonic suppression

A novel 2nd–order antenna with filtering performance and two-octave harmonic suppression is proposed. In order to reduce the effects of the harmonics of the antenna, two types of antennas (PIFA and patch) with different resonant characteristics are integrated into the design. Compared with the traditional patch antennas, this integrated work can not only eliminate the high-order harmonics of the antenna but also improve the in-band bandwidth and frequency selectivity. The 2nd and 4th–order harmonics of the patch are suppressed because of the detuned harmonic performance of the PIFA and patch. The 3rd-order harmonic is eliminated by integrating notch resonators in the PIFA. A prototype works at 2.4 GHz is developed to demonstrate the PIFA-patch integration scheme. Measured and simulated results of antennas agree well with each other, demonstrating good performance of bandwidth, 2nd-order filtering, radiation and wideband harmonic suppression (up to 11 GHz)

A novel multi-band directional antenna for wireless communications

A novel multiband patch antenna with unidirectional radiation is proposed by integrating resonators in the design. The multiple frequency bands are achieved based on a coupled resonators network. The topology and design methodology are detailed. The patch not only works as the last order resonator of the network but also the radiating element. Using this approach, multiple bands can be achieved without changing the shape of the radiation element. In addition, the operation bands can be adjusted by adjusting the coupling between the resonators. In this work, the four bands are designed at 4.6, 5.05, 5.8 and 6.3 GHz as a proof-of-concept. The prototype is fabricated and tested and measured results agree very well with the simulations, showing an excellent performance in terms of impedance matching, radiation patterns, gains and cross polarization discrimination (XPD)

A shared-aperture dual-band dual-polarized filtering-antenna-array with improved frequency response

In this paper, a novel dual-band dual-polarized (DBDP) array antenna with low frequency ratio and integrated filtering characteristics is proposed. By employing a dual-mode stub-loaded resonator (SLR) to feed and tune with two patches, the two feed networks for each polarization can be combined, resulting in the reduction of the feed networks and the input ports. In addition, owing to the native dual resonant features of the SLR, the proposed antenna exhibits 2nd-order filtering characteristics with improved bandwidth and out-of-band rejections. The antenna is synthesized and the design methodology is explained. The coupling coefficients between the SLR and the patches are investigated. To verify the design concept, a C/X-band element and a 2 × 2 array are optimized and prototyped. Measured results agree well with the simulations, showing good performance in terms of bandwidth, filtering, harmonic suppression and radiation at both bands. Such an integrated array design can be used to simplify the feed of a reflector antenna. To prove the concept, a paraboloid reflector fed by the proposed array is conceived and measured directivities of 24.6 dBi (24.7 dBi) and 28.6 dBi (29.2 dBi) for the X-polarization (Y-polarization) are obtained for the low- and high-band operations, respectively

Urban-Rural Differences in the Associations of Risk Factors With Epilepsy Based on the California Health Interview Survey: A Multiple Logistic Regression Analysis

Background: Previous studies provided inconsistent associations of smoking, stroke, and serious psychological distress (SPD) with epilepsy while urban-rural differences in the associations of risk factors with epilepsy are not well documented. Objectives: This study aimed to evaluate the associations of lifestyle, health conditions, and SPD with epilepsy and to examine whether the associations differ between urban and rural areas. Patients and Methods: A total of 604 adults with epilepsy and 42416 controls were selected from the 2005 California Health Interview Survey. Weighted univariate and multiple logistic regression analyses were used to estimate the associations of potential factors (behavioral factors, SPD, social factors and health conditions) with epilepsy. The odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results: The overall prevalence of epilepsy was 1.3% and the prevalence was higher in urban area than rural area (1.4 vs. 1.1%). The prevalence of SPD was 11% in cases and 4% in controls, respectively. The percentage of stroke was higher in cases than in controls (9% vs. 2%). After adjusting for other factors using multiple logistic regression, current smoking, stroke, cancer, SPD and living in urban were positively significantly associated with epilepsy (OR = 1.74, 95% CI = 1.28 - 2.38; OR = 4.81, 95% CI = 3.13 - 7.41; OR = 1.52, 95% CI = 1.12 - 2.06; OR = 2.02, 95% CI = 1.39 - 2.92, and OR = 1.4, 95% CI = 1.08 - 1.81, respectively); while binge drinking was negatively associated with epilepsy (OR = 0.65, 95% CI = 0.43 - 0.99). Stratified by residence, in the urban area, current smoking and race were only associated with epilepsy. Stroke and SPD showed stronger association with epilepsy in the rural area (OR = 7.63, 95% CI = 3.68 - 15.8, and OR = 3.14, 95% CI = 1.52 - 6.47, respectively) comparing with urban region (OR = 4.51, 95% CI = 2.79 - 7.28 and OR = 1.9, 95% CI = 1.27 - 2.86, respectively)

Urban-Rural Differences in the Associations of Risk Factors With Epilepsy Based on the California Health Interview Survey: A Multiple Logistic Regression Analysis

Background: Previous studies provided inconsistent associations of smoking, stroke, and serious psychological distress (SPD) with epilepsy while urban-rural differences in the associations of risk factors with epilepsy are not well documented. Objectives: This study aimed to evaluate the associations of lifestyle, health conditions, and SPD with epilepsy and to examine whether the associations differ between urban and rural areas. Patients and Methods: A total of 604 adults with epilepsy and 42416 controls were selected from the 2005 California Health Interview Survey. Weighted univariate and multiple logistic regression analyses were used to estimate the associations of potential factors (behavioral factors, SPD, social factors and health conditions) with epilepsy. The odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results: The overall prevalence of epilepsy was 1.3% and the prevalence was higher in urban area than rural area (1.4 vs. 1.1%). The prevalence of SPD was 11% in cases and 4% in controls, respectively. The percentage of stroke was higher in cases than in controls (9% vs. 2%). After adjusting for other factors using multiple logistic regression, current smoking, stroke, cancer, SPD and living in urban were positively significantly associated with epilepsy (OR = 1.74, 95% CI = 1.28 - 2.38; OR = 4.81, 95% CI = 3.13 - 7.41; OR = 1.52, 95% CI = 1.12 - 2.06; OR = 2.02, 95% CI = 1.39 - 2.92, and OR = 1.4, 95% CI = 1.08 - 1.81, respectively); while binge drinking was negatively associated with epilepsy (OR = 0.65, 95% CI = 0.43 - 0.99). Stratified by residence, in the urban area, current smoking and race were only associated with epilepsy. Stroke and SPD showed stronger association with epilepsy in the rural area (OR = 7.63, 95% CI = 3.68 - 15.8, and OR = 3.14, 95% CI = 1.52 - 6.47, respectively) comparing with urban region (OR = 4.51, 95% CI = 2.79 - 7.28 and OR = 1.9, 95% CI = 1.27 - 2.86, respectively). Conclusions: Smoking, stroke, and SPD were associated with epilepsy; while the associations differed between urban and rural areas

Dual-band circularly-polarized shared-aperture array for C/X-Band satellite communications

A novel method of achieving a single-feed circularly-polarized (CP) microstrip antenna with both broad impedance bandwidth and axial ratio (AR) bandwidth is presented. The CP characteristics are generated by employing a resonator to excite the two orthogonal modes of the patch via two coupling paths and the required 90 o phase difference is achieved by using the different orders of the two paths. The presented method, instead of conventional methods that power dividers and phase delay lines are usually required, not only significantly enhances the bandwidths of the antenna, but also results in a compact feed, reduced loss and high gain. Based on this method, a dual-band shared-aperture CP array antenna is implemented for C/X-band satellite communications. The antenna aperture includes a 2 × 2 array at C-band and a 4 ×4 array at X-band. To accommodate the C/X-band elements into the same aperture while achieving a good isolation between them, the C-band circular patches are etched at the four corners. The measured results agree well with the simulations, showing a wide impedance bandwidth of 21% and 21.2% at C-and X-band, respectively. The C-and X-band 3-dB AR bandwidths are 13.2% and 12.8%. The array also exhibits a high aperture efficiency of over 55%, low side-lobe (C-band: −12.5 dB; X-band: −15 dB) and high gain (C-band: 14.5 dBic; X-band: 17.5 dBic)

Dual-Band Full-Duplex Tx/Rx Antennas for Vehicular Communications

This paper proposes a novel dual-band full-duplex antenna/array for intelligent transport systems (ITS) applications. Different from traditional single-port single-band antennas, the two ports of the antenna are highly isolated and designed to operate at different frequency bands simultaneously. Such a property could support the full-duplex operation-mode, which significantly simplifies the complexity of the RF frontend subsystem. The other contribution of this work is that multiple functions such as filtering, duplexing and radiation are combined into one single device, resulting in a simplified RF frontend. This co-design multifunctional device could also remove the separate filters, duplexers and interfaces between them, resulting in the reduction of the size, weight and cost. In addition, cross-coupling is investigated and employed to generate additional transmission zeros so as to improve the channel isolation and out-of-band interference. To verify the concept, an antenna element and two 2 × 2 arrays at C-band are designed, prototyped and tested. All the measurements agree well with the simulations, showing two full-duplex channels of 4.58 - 4.83 GHz and 5.86 - 6.2 GHz for transmitting and receiving, respectively. The proposed antennas also exhibit excellent performance in terms of channel isolations, frequency selectivity, out-of-band rejections and gains

Moby: Empowering 2D Models for Efficient Point Cloud Analytics on the Edge

3D object detection plays a pivotal role in many applications, most notably autonomous driving and robotics. These applications are commonly deployed on edge devices to promptly interact with the environment, and often require near real-time response. With limited computation power, it is challenging to execute 3D detection on the edge using highly complex neural networks. Common approaches such as offloading to the cloud induce significant latency overheads due to the large amount of point cloud data during transmission. To resolve the tension between wimpy edge devices and compute-intensive inference workloads, we explore the possibility of empowering fast 2D detection to extrapolate 3D bounding boxes. To this end, we present Moby, a novel system that demonstrates the feasibility and potential of our approach. We design a transformation pipeline for Moby that generates 3D bounding boxes efficiently and accurately based on 2D detection results without running 3D detectors. Further, we devise a frame offloading scheduler that decides when to launch the 3D detector judiciously in the cloud to avoid the errors from accumulating. Extensive evaluations on NVIDIA Jetson TX2 with real-world autonomous driving datasets demonstrate that Moby offers up to 91.9% latency improvement with modest accuracy loss over state of the art.Comment: Accepted to ACM International Conference on Multimedia (MM) 202

Antioxidant activities of polysaccharide fractions isolated from burley tobacco flowers

The crude polysaccharide extracted from the flowers of burley tobacco hybrid Eyan 1 was fractionated on a Sepharose CL-6B chromatography to get two purified polysaccharide fractions (termed Fr-I and Fr-II). The monocarbohydrate compositions revealed both fractions were heteropolysaccharide. Fr-I was mainly composed of mannose, galactose, ribose and arabinose, while Fr-II was composed of mannose, galactose and glucose. The IR spectrum of Fr-I and Fr-II revealed the typical characteristics with β-configuration. Furthermore, TGA (Thermogravimetric analysis) indicated the degradation temperature (Td) of the Fr-I and Fr-II was 210 °C and 185 °C, respectively. Both Fr-I and Fr-II possessed good scavenging abilities on hydroxyl radicals (IC50 8.26 mg/ml and 6.23 mg/ml, respectively) and DPPH radicals (IC50 20.3±1.20 µg/ml, 17.5±1.28 µg/ml, respectively). Fr-II showed higher antioxidant properties than Fr-I (p < 0.05). In a 13C NMR analysis of Fr-II, three anomeric peaks appeared at 102.95, 95.79 and 91.85 ppm, which were assigned to the mannose (C-1), galactose (C-1) and glucose (C-1) residues, respectively