Factor graph based detection approach for high-mobility OFDM systems with large FFT modes

In this article, a novel detector design is proposed for orthogonal frequency division multiplexing (OFDM) systems over frequency selective and time varying channels. Namely, we focus on systems with large OFDM symbol lengths where design and complexity constraints have to be taken into account and many of the existing ICI reduction techniques can not be applied. We propose a factor graph (FG) based approach for maximum a posteriori (MAP) symbol detection which exploits the frequency diversity introduced by the ICI in the OFDM symbol. The proposed algorithm provides high diversity orders allowing to outperform the free-ICI performance in high-mobility scenarios with an inherent parallel structure suitable for large OFDM block sizes. The performance of the mentioned near-optimal detection strategy is analyzed over a general bit-interleaved coded modulation (BICM) system applying low-density parity-check (LDPC) codes. The inclusion of pilot symbols is also considered in order to analyze how they assist the detection process

A high-performance 8 nV/root Hz 8-channel wearable and wireless system for real-time monitoring of bioelectrical signals

Background: It is widely accepted by the scientific community that bioelectrical signals, which can be used for the identification of neurophysiological biomarkers indicative of a diseased or pathological state, could direct patient treatment towards more effective therapeutic strategies. However, the design and realisation of an instrument that can precisely record weak bioelectrical signals in the presence of strong interference stemming from a noisy clinical environment is one of the most difficult challenges associated with the strategy of monitoring bioelectrical signals for diagnostic purposes. Moreover, since patients often have to cope with the problem of limited mobility being connected to bulky and mains-powered instruments, there is a growing demand for small-sized, high-performance and ambulatory biopotential acquisition systems in the Intensive Care Unit (ICU) and in High-dependency wards. Finally, to the best of our knowledge, there are no commercial, small, battery-powered, wearable and wireless recording-only instruments that claim the capability of recording electrocorticographic (ECoG) signals. Methods: To address this problem, we designed and developed a low-noise (8 nV/√Hz), eight-channel, battery-powered, wearable and wireless instrument (55 × 80 mm2). The performance of the realised instrument was assessed by conducting both ex vivo and in vivo experiments. Results: To provide ex vivo proof-of-function, a wide variety of high-quality bioelectrical signal recordings are reported, including electroencephalographic (EEG), electromyographic (EMG), electrocardiographic (ECG), acceleration signals, and muscle fasciculations. Low-noise in vivo recordings of weak local field potentials (LFPs), which were wirelessly acquired in real time using segmented deep brain stimulation (DBS) electrodes implanted in the thalamus of a non-human primate, are also presented. Conclusions: The combination of desirable features and capabilities of this instrument, namely its small size (~one business card), its enhanced recording capabilities, its increased processing capabilities, its manufacturability (since it was designed using discrete off-the-shelf components), the wide bandwidth it offers (0.5 – 500 Hz) and the plurality of bioelectrical signals it can precisely record, render it a versatile and reliable tool to be utilized in a wide range of applications and environments

Laparoscopic resection of an esophageal epiphrenic diverticulum

Epiphrenic diverticulum of the esophagus is an uncommon disease. In the light of the benefits of minimally invasive treatment of such a functional disorder, we used the laparoscopic approach for resection of an epiphrenic diverticulum. We found that laparoscopic repair of symptomatic esophageal epiphrenic diverticula is a safe and effective technique with minimal postoperative pain and morbidity. It should be considered as an alternative to the traditional transthoracic approach, and may become the standard technique

Laparoscopic repair of a Morgagni-Larrey hernia: Report of three cases

Morgagni-Larrey hernia is a rare type of diaphragmatic hernia, the diagnosis of which is made incidentally by routine chest X-ray film. We describe a technique for the laparoscopic repair of Morgagni-Larrey hernia which was successfully performed in three adult patients; two women and one man. Two of the patients were asymptomatic and had herniation of only omentum into the right hemithorax; however, one was symptomatic and had herniation of the omentum and large bowel. Tension-free closure of the defects was done using Prolene mesh with a hernia stapler, helical fastener, and Endostitch. There were no early complications and the patients were discharged on the fourth postoperative day. The mean follow-up period was 41 months, and there has been no late morbidity or mortality related to this procedure. Using a laparoscopic approach to repair a Morgagni-Larrey hernia provides an excellent view of the surgical field and allows easy manipulation with minimal surgical trauma, followed by rapid recovery of the patient

Petrogenesis and U-Pb zircon chronology of adakitic porphyries within the Kop ultramafic massif (eastern Pontides orogenic belt, NE Turkey)

Abstract not availableYener Eyuboglu, Francis O. Dudas, M. Santosh, Keewook Yi, Sanghoon Kwon, Enver Akaryal

Lack of evidence that obesity is a cause of pilonidal sinus disease

Objective: To find out whether pilonidal sinus is more common among obese people

Laparoscopic repair of ventral and incisional hernias: Our experience in 150 patients

Background: Incisional hernias develop in 2 to 20% of laparotomy incisions. Approximately 100,000 ventral hernias are operated on each year in the United States. The reported recurrence rates for open repair are 25-52% for primary and 12.5-19% for mesh repair. Compared to the open technique, laparoscopic repair has low rates of complications and recurrence, greater patient acceptance, and shorter hospital stay