2,090 research outputs found
Update in management of hepatocellular carcinoma in Eastern population
Hepatocellular carcinoma (HCC) is one of the commonest malignant tumours in the East. Although the management of HCC in the West is mainly based on the Barcelona Clinic for Liver Cancer staging, it is considered too conservative by Asian countries where the number of HCC patients is huge. Scientific and clinical advances were made in aspects of diagnosis, staging, and treatment of HCC. HCC is well known to be associated with cirrhosis and the treatment of HCC must take into account the presence and stage of chronic liver disease. The major treatment modalities of HCC include: (1) surgical resection; (2) liver transplantation; (3) local ablation therapy; (4) transarterial locoregional treatment; and (5) systemic treatment. Among these, resection, liver transplantation and ablation therapy for small HCC are considered as curative treatment. Portal vein embolisation and the associating liver partition with portal vein ligation for staged hepatectomy may reduce dropout in patients with marginally resectable disease but the midterm and long-term results are still to be confirmed. Patient selection for the best treatment modality is the key to success of treatment of HCC. The purpose of current review is to provide a description of the current advances in diagnosis, staging, preoperative liver function assessment and treatment options for patients with HCC in the east. © 2015 Baishideng Publishing Group Inc.published_or_final_versio
On Surface Wave Propagation Characteristics of Porosity-Based Reconfigurable Surfaces
Reconfigurable surfaces facilitating energy-efficient, intelligent surface wave propagation have recently emerged as a technology that finds applications in many-core systems and 6G wireless communications. In this paper, we consider the porosity-based reconfigurable surface where there are cavities that can be filled on-demand with fluid metal such as Galinstan, in order to create adaptable channels for efficient wave propagation. We aim to investigate the propagation phenomenon of signal fluctuation resulting from the diffraction of discrete porosity and study how different porosity patterns affect this phenomenon. Our results cover the frequency range between 21.7GHz and 31.6GHz when a WR-34 waveguide is used as the transducer
Reconfigurable Surface Wave Platform Using Fluidic Conductive Structures
Surface wave inherently has less propagation loss as it adheres to the surface and minimizes unwanted dissipation in space. Recently, they find applications in network-on-chip (NoC) communications and intelligent surface aided mobile networked communications. This paper puts forward a reconfigurable surface wave platform (RSWP) that utilizes liquid metal to produce highly energy-efficient and adaptive pathways for surface wave transmission. Our simulation results illustrate that the proposed RSWP using Galinstan can obtain a 25dB gain in the electric field for a propagation distance of 35 at 30G Hz wheredenotes the wavelength. Moreover, less than 1dB loss is observed even at a distance of 50, and a pathway with right-angled turns can also be created with only a 3. 5dB loss at the turn
Enhancing and Localizing Surface Wave Propagation with Reconfigurable Surfaces
As an attempt to develop a reconfigurable surface architecture that can use liquid metal such as Galinstan to shape surface channels on demand, this paper considers a punctured surface where cavities are evenly distributed and can be filled with liquid metal potentially via digitally controlled pumps. In this paper, we look at the benefits of such architecture in terms of surface-wave signal enhancement and isolation, and examine how various system parameters impact the performance using full wave 3-dimensional electromagnetic simulations. It is shown that extraordinary signal shaping can be obtained
A Vision to Smart Radio Environment: Surface Wave Communication Superhighways
IEEE Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart radio environment by using software-defined materials or programmable metasurfaces for establishing favorable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on intelligent surfaces for future smart radio environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off radio waves intelligently toward intended user terminals. In the proposed SW vision, energy efficiency can be much higher, due to more desirable propagation characteristics compared to open-space radio propagation. The fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-less data access. We shall outline the opportunities and challenges arising from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways
Evaluating the incidence, clinical significance and predictors for vocal cord palsy and incidental laryngopharyngeal conditions before elective thyroidectomy: is there a case for routine laryngoscopic examination?
Background: Routine preoperative laryngeal examination remains controversial. We aimed to assess the utility of preoperative routine flexible laryngoscopy (FL) by looking at the incidence, clinical significance and predictors for preoperative vocal cord paresis (VCP) and incidental laryngopharyngeal conditions (LPC) in our consecutive cohort. Methods: A total of 302 patients underwent laryngeal examination by an independent otorhinolaryngologist and were specifically asked about voice/swallowing symptoms suggestive of VCP 1 day before surgery. As well as vocal cord (VC) mobility, the naso-pharynx and larynx were examined using FL. Any VCP and/or LPC was recorded. VCP was defined as reduced or absent movement in one or more VC. An LPC was considered clinically significant if the ensuing thyroidectomy was changed or deferred. Results: Seven (2.3 %) patients had preoperative VCP, while an additional seven patients had an incidental LPC. Of the seven VCPs, five were caused by previous thyroidectomy, while two were caused by a benign goitre. The incidence of asymptomatic VCP in a previously non-operated cohort was 1/245 (0.41 %). Voice/swallowing symptoms (p = 0.033) and previous thyroidectomy (p < 0.001) were the two significant predictors for VCP. The seven incidental LPCs were vallecular cyst (n = 1), VC scar and polyp (n = 2), nasopharyngeal cyst and polyp (n = 3) and redundant arytenoid mucosa (n = 1); however, as they were benign, all seven patients proceeded to thyroidectomy as planned. Conclusions: Given the low incidence (0.41 %) of asymptomatic VCP in a previously non-operated cohort and that none of the seven LPCs were considered clinically significant, routine preoperative laryngoscopic examination should be reserved for those with previous thyroidectomy and/or voice/swallowing symptoms. © 2013 Société Internationale de Chirurgie.postprin
Weighted Sum Secrecy Rate Maximization using Intelligent Reflecting Surface
This paper aims to investigate the benefit of using intelligent reflecting surface (IRS) in multi-user multiple-input single-output (MU-MISO) systems, in the presence of eavesdroppers. We maximize the weighted sum secrecy rate by jointly designing the secure beamforming (BF), the artificial noise (AN), as well as the phase shift of the IRS. An alternating optimization (AO) method is proposed to deal with the formulated non convex problem. In particular, the secure beamforming and AN jamming matrix are optimally designed via the successive convex approximation (SCA) approach for given phase shift, which can be derived by considering the alternating direction method of multiplier (ADMM) and element-wise block coordinate decent (EBCD) methods. Finally, simulation results are presented to show the benefit of the IRS in terms of improving the secrecy performance, when compared to other methods
Personnel dose reduction in 90Y microspheres liver-directed radioembolization: from interventional radiology suite to patient ward
Robust AN-Aided Secure Beamforming and Power Splitting in Wireless-Powered AF Relay Networks
In this letter, we investigate the secrecy design in a wireless-powered amplify-and-forward relay network, where the relay is energy constrained and powered by the signal from the transmitter. Specifically, by adopting the power splitting (PS) scheme at the relay, we investigate the worst-case secrecy rate maximization by jointly designing the relay beamforming matrix, artificial noise covariance, and the PS ratio. However, the formulated problem is highly nonconvex due to the secrecy rate function and the dynamic relay power constraint. By exploiting the hidden convexity, we transform the original problem to a solvable reformulation via the successive convex approximation and constrained concave–convex procedure, which can provide a high-level approximated beamforming solution. Then, an iterative algorithm is proposed to obtain the solution. Numerical results showed the effectiveness of the proposed robust scheme
CD4+ T Cells Targeting Dominant and Cryptic Epitopes from Bacillus anthracis Lethal Factor.
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