Publications by authors named "Robert Giles"

After moderate to severe traumatic brain injury (TBI), sleep disturbance commonly emerges during the confused post-traumatic amnesia (PTA) recovery stage. However, the evaluation of early sleep disturbance during PTA, its recovery trajectory, and influencing factors is limited. This study aimed to evaluate sleep outcomes in patients experiencing PTA using ambulatory gold-standard polysomnography (PSG) overnight and salivary endogenous melatonin (a hormone that influences the sleep-wake cycle) assessment at two time-points.

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Background Away rotations allow emergency medicine (EM)-bound fourth-year medical students to experience a residency program's educational culture and influence the ranking of residency programs. The financial cost and geographic distance have limited student participation in away electives. In recent years, COVID-19 pandemic-related restrictions on away rotations resulted in the creation of multiple virtual courses.

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Expression of concern for 'Direct observation of the THz Kerr effect (TKE) in deionized, distilled and buffered (PBS) water' by Andrzej Dobek , , 2017, , 26749-26757, https://doi.org/10.1039/c7cp04061j.

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Study Objectives: Sleep disturbance often emerges in the early recovery phase following a moderate to severe traumatic brain injury, known as posttraumatic amnesia. Actigraphy is commonly employed to assess sleep, as it is assumed that patients in posttraumatic amnesia (who display confusion, restlessness, and agitation) would better tolerate this measure over gold-standard polysomnography (PSG). This study evaluated the agreement between PSG and actigraphy for determining (sleep/wake time, sleep efficiency, sleep latency, and awakenings) in patients experiencing posttraumatic amnesia.

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Aims: Undilatable stents with severe peri-stent calcification are an important cause of target lesion failure and therapeutic options are limited. We report our initial experience with the safety and efficacy of excimer laser coronary atherectomy (ELCA)-assisted expansion of undilatable stents.

Methods And Results: ELCA was performed with saline, blood and contrast-enhanced trains.

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Background: Early-onset sleep disturbance is common following moderate to severe traumatic brain injury (TBI) and often emerges while patients are in posttraumatic amnesia (PTA). However, sleep disruptions during this subacute recovery phase are not well-defined, and research often utilizes indirect measures (actigraphy) that quantify sleep based on activity. This study aims to examine sleep macro-architecture and sleep quality directly with ambulatory polysomnography (PSG) and measure endogenous salivary melatonin levels for patients experiencing PTA following moderate to severe TBI.

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Nonlinear THz pump-optical probe (THz-OKE) measurements in deionized, distilled and buffered (PBS) water are reported. A laser system that produces pulses at 800 nm, 30 fs FWHM, at a repetition rate of 1 kHz and an energy of 6 μJ per pulse, was a source of the probe optical beam and of the pump beam of THz 2 ps pulses. The electric field strength inducing birefringence in water samples was E = 1.

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Terahertz (THz) imaging is progressing as a robust platform for myriad applications in the field of security, health, and material science. The THz regime, which comprises wavelengths spanning from microns to millimeters, is non-ionizing and has very low photon energy: Making it inherently safe for biological imaging. Colorectal cancer is one of the most common causes of death in the world, while the conventional screening and standard of care yet relies exclusively on the physician's experience.

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Background: Infection is one of the most feared complications of cardiac implantable electronic devices. We report microbiology, antimicrobial therapy and infection recurrence in patients with cardiac device infection (CDI) treated with transvenous lead extraction (TLE) at a single centre over a 20-year period.

Methods: We identified a cohort of consecutive patients undergoing TLE for CDI by a single operator at a single high volume centre.

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Biomedical applications of terahertz (THz) radiation are appealing because THz radiation is nonionizing and has the demonstrated ability to detect intrinsic contrasts between cancerous and normal tissue. A linear polarization-sensitive detection technique for tumor margin delineation has already been demonstrated; however, utilization of a circular polarization-sensitive detection technique has yet to be explored at THz frequencies. A reflective, continuous-wave THz imaging system capable of illuminating a target sample at 584 GHz with either linearly or circularly polarized radiation, and capable of collecting both cross- and copolarized signals remitted from the target, is implemented.

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Background: Complications related to a cardiac implantable electronic device sometimes require transvenous lead extraction (TLE). We report long-term follow-up of patients undergoing TLE, particularly mortality, recurrent device infection, and need for repeat procedures.

Methods And Results: Consecutive patients undergoing TLE at a high-volume center were assessed for characteristics, indications, and outcomes.

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Aims: This study aims to validate the joint ACCF/AHA/ESC/WHF Universal Definition of peri-procedural myocardial infarction (PMI) with high sensitivity troponin T (hsTnT).

Methods: A retrospective cohort study encompassing patients admitted to our institution between May 2012 and April 2013 was performed.

Results: 630 patients underwent percutaneous coronary interventions during the study period.

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A 42 year-old man presented for elective percutaneous lead extraction for pacemaker redundancy. The procedure was performed supine under general anaesthesia via the right femoral vein and was complicated by acute inferior ST elevation and hypotension. Urgent transoesophageal echocardiogram showed inferior left ventricular hypokinesis, right ventricular impairment, a patent foramen ovale and air in the left ventricle.

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We demonstrate the design and development of an innovative single-channel terahertz (THz) prototype endoscopic imaging system based on flexible metal-coated THz waveguides and a polarization specific detection technique. The continuous-wave (CW) THz imaging system utilizes a single channel to transmit and collect the reflected intrinsic THz signal from the sample. Since the prototype system relies on a flexible waveguide assembly that is small enough in diameter, it can be readily integrated with a conventional optical endoscope.

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Article Synopsis
  • A new textile metamaterial was developed by integrating metal wires into polymer yarn, leading to the formation of extended states similar to split-ring resonators.
  • Simulations indicate that these states can be readily adjusted by altering the material's geometry.
  • Measurements in the low terahertz range showed peaks that correlate with a polarization-dependent resonator model, suggesting potential use of these fabrics in flexible metamaterials for gigahertz and terahertz applications.
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Aims: Indications for cardiovascular implantable electronic devices continue to evolve, which has led to an increasing requirement for transvenous lead extraction. We explore the indications, complications, and success rates involved in the removal of pacemaker and implantable cardioverter-defibrillator (ICD) leads in a high-volume centre, over 20 years.

Methods And Results: We performed a retrospective analysis of all consecutive patients undergoing transvenous lead extraction by a single operator at a single centre between 1993 and 2012.

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Attenuation characteristics of hollow, flexible, metal and metal/dielectric coated polycarbonate waveguides were investigated using an optically pumped far infrared (FIR) laser at 215 µm. The bending loss of silver coated polycarbonate waveguides were measured as a function of various bending angles, bending radii, and bore diameters. Minimal propagation losses of 1.

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We tested the hypothesis that polarization sensitive optical and terahertz imaging may be combined for accurate nonmelanoma skin cancer (NMSC) delineation. Nine NMSC specimens were imaged. 513 μm and 440 nm wavelengths were used for terahertz and optical imaging, respectively.

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Background And Objective: Continuous wave terahertz imaging has the potential to offer a safe, noninvasive medical imaging modality for delineating human skin cancers. Terahertz pulse imaging (TPI) has already shown that there is contrast between basal cell carcinoma and normal skin. Continuous-wave imaging offers a simpler, lower cost alternative to TPI.

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Aims: This is the initial report of stent deformation/pseudofracture of the 7 crown Endeavor/Micro Driver stent platform (2.25-2.75 mm), whereby the post-dilation balloon catches and causes major stent deformation angiographically appearing as a large stent fracture.

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A coherent transceiver using a THz quantum cascade (TQCL) laser as the transmitter and an optically pumped molecular laser as the local oscillator has been used, with a pair of Schottky diode mixers in the receiver and reference channels, to acquire high-resolution images of fully illuminated targets, including scale models and concealed objects. Phase stability of the received signal, sufficient to allow coherent image processing of the rotating target (in azimuth and elevation), was obtained by frequency-locking the TQCL to the free-running, highly stable optically pumped molecular laser. While the range to the target was limited by the available TQCL power (several hundred microwatts) and reasonably strong indoor atmospheric attenuation at 2.

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A methodology to generate 2-thio- and 2-oxoimidazoles through an addition-cyclization-isomerization reaction of propargylcyanamides with thiol and alcohol nucleophiles is described. In general, the reaction sequence allows for the rapid formation of highly substituted 2-thio- and 2-oxoimidazoles in good to excellent yields.

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