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To assess the effect of tranexamic acid in head and neck surgical procedures.
A prospective, double-blind and randomised, parallel group, placebo-controlled clinical trial was conducted. Ninety-two patients undergoing various head and neck surgical procedures were randomised. Subjects received seven infusions of coded drugs (tranexamic acid or normal saline) starting at the time of skin closure. Haematological, biochemical, blood loss and other parameters were observed by the staff, who were blinded to patients’ group allocation (case or control).
Patients were analysed on the basis of type of surgery. Fifty patients who had undergone surgical procedures, including total thyroidectomy, total parotidectomy, and various neck dissections with or without primary tumour excision, were included in the first group. The second group comprised 41 patients who had undergone hemithyroidectomy, lobectomy or superficial parotidectomy. There was no statistical difference in blood parameters between both groups. There was a reduction in post-operative drain volume, but this was not significant.
Although this prospective, randomised, placebo-controlled clinical trial found a reduction in post-operative drain volume in tranexamic acid groups, the difference was not statistically significant between the various head and neck surgical procedure groups.
Introduction: Acute aortic syndrome (AAS) is a time sensitive aortic catastrophe that is often misdiagnosed. There are currently no Canadian guidelines to aid in diagnosis. Our goal was to adapt the existing American Heart Association (AHA) and European Society of Cardiology (ESC) diagnostic algorithms for AAS into a Canadian evidence based best practices algorithm targeted for emergency medicine physicians. Methods: We chose to adapt existing high-quality clinical practice guidelines (CPG) previously developed by the AHA/ESC using the GRADE ADOLOPMENT approach. We created a National Advisory Committee consisting of 21 members from across Canada including academic, community and remote/rural emergency physicians/nurses, cardiothoracic and cardiovascular surgeons, cardiac anesthesiologists, critical care physicians, cardiologist, radiologists and patient representatives. The Advisory Committee communicated through multiple teleconference meetings, emails and a one-day in person meeting. The panel prioritized questions and outcomes, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations. The algorithm was prepared and revised through feedback and discussions and through an iterative process until consensus was achieved. Results: The diagnostic algorithm is comprised of an updated pre test probability assessment tool with further testing recommendations based on risk level. The updated tool incorporates likelihood of an alternative diagnosis and point of care ultrasound. The final best practice diagnostic algorithm defined risk levels as Low (0.5% no further testing), Moderate (0.6-5% further testing required) and High ( >5% computed tomography, magnetic resonance imaging, trans esophageal echocardiography). During the consensus and feedback processes, we addressed a number of issues and concerns. D-dimer can be used to reduce probability of AAS in an intermediate risk group, but should not be used in a low or high-risk group. Ultrasound was incorporated as a bedside clinical examination option in pre test probability assessment for aortic insufficiency, abdominal/thoracic aortic aneurysms. Conclusion: We have created the first Canadian best practice diagnostic algorithm for AAS. We hope this diagnostic algorithm will standardize and improve diagnosis of AAS in all emergency departments across Canada.
To compare combined conventional Freer medialisation and controlled synechiae, performed for middle meatal access (during the initial steps of functional endoscopic sinus surgery) and post-operative middle turbinate medialisation, with basal lamella relaxing incision, the latter of which is a single step for achieving both middle meatal access and post-operative medialisation. The study also compared the effects of controlled synechiae and basal lamella relaxing incision on post-operative olfaction.
A randomised prospective study was performed on 52 nasal cavity sides (32 patients). Only basal lamella relaxing incision was performed in one group, and both conventional medialisation and controlled synechiae were performed in the other. Intra-operative and post-operative photography was used to measure the middle meatal area. A pocket smell test was used to assess olfaction.
There were no significant differences in operative middle meatal access and post-operative medialisation of the middle turbinate. Post-operative olfaction was affected more in the combined conventional medialisation and controlled synechiae group, compared to the basal lamella relaxing incision group, but this finding was not statistically significant.
Basal lamella relaxing incision is an effective single-step technique for achieving adequate middle meatal access and post-operative medialisation, with no significant effect on olfaction.
Predicting recurrent Clostridium difficile infection (rCDI) remains difficult. METHODS. We employed a retrospective cohort design. Granular electronic medical record (EMR) data had been collected from patients hospitalized at 21 Kaiser Permanente Northern California hospitals. The derivation dataset (2007–2013) included data from 9,386 patients who experienced incident CDI (iCDI) and 1,311 who experienced their first CDI recurrences (rCDI). The validation dataset (2014) included data from 1,865 patients who experienced incident CDI and 144 who experienced rCDI. Using multiple techniques, including machine learning, we evaluated more than 150 potential predictors. Our final analyses evaluated 3 models with varying degrees of complexity and 1 previously published model.
Despite having a large multicenter cohort and access to granular EMR data (eg, vital signs, and laboratory test results), none of the models discriminated well (c statistics, 0.591–0.605), had good calibration, or had good explanatory power.
Our ability to predict rCDI remains limited. Given currently available EMR technology, improvements in prediction will require incorporating new variables because currently available data elements lack adequate explanatory power.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
A scalable approach for synthesis of ultra-thin (<10 nm) transition metal dichalcogenides (TMD) films on stretchable polymeric materials is presented. Specifically, magnetron sputtering from pure TMD targets, such as MoS2 and WS2, was used for growth of amorphous precursor films at room temperature on polydimethylsiloxane substrates. Stacks of different TMD films were grown upon each other and integrated with optically transparent insulating layers such as boron nitride. These precursor films were subsequently laser annealed to form high quality, few-layer crystalline TMDs. This combination of sputtering and laser annealing is commercially scalable and lends itself well to patterning. Analysis by Raman spectroscopy, scanning probe, optical, and transmission electron microscopy, and x-ray photoelectron spectroscopy confirm our assertions and illustrate annealing mechanisms. Electrical properties of simple devices built on flexible substrates are correlated to annealing processes. This new approach is a significant step toward commercial-scale stretchable 2D heterostructured nanoelectronic devices.
The aluminum doped SrFe12O19 hexaferrite samples were prepared via co-precipitation method using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The effects of CTAB content (x = 0, 1, 3, 6 and 9 wt. %) on the structure, morphology, and electrocapacitive behavior of the SrFe10Al2O19 nanoparticles were investigated. The use of CTAB was observed to be effective in eliminating α-Fe2O3 phase from samples. Morphological changes including grain and crystallite size was noticed with the increase in the CTAB content. With the increase in CTAB, powder particles grew in size and thickness. A concomitant increase in magnetization due to crystal growth was observed. Electrochemical performance of supercapacitors was evaluated by cyclic voltammetry (CV). Highest power density of 368.09 WKg-1 and energy density of 0.916 WhKg-1 was observed for 3% and 1% CTAB samples, respectively.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
To assess the role of video endoscopy in evaluating velopharyngeal incompetence and investigate a possible relationship between velopharyngeal incompetence type and speech defect in cleft palate patients.
A prospective study of 28 pre- or post-operative cleft palate patients with speech defects who attended Plastic Surgery–Cleft Palate and ENT out-patient clinics was performed. The velar defect type was determined using a flexible endoscope and findings were video recorded. Speech pathology was assessed using the cleft palate audit protocol for speech.
A significant, clinically relevant relationship was noted between the perceived characteristics of hypernasality and velopharyngeal insufficiency type. Hypernasal speech was a definite clinical indicator of velopharyngeal incompetence, and the type 1 velopharyngeal defect was most common. Type 1 velopharyngeal coronal-type dysfunction was strongly associated with hypernasality (p < 0.05). When speech substitution was noted, type 2 velopharyngeal (or sagittal) incompetence could be predicted (p < 0.05).
In the management of cleft palate patients, it is important that surgical correction of the defect and achieving velopharyngeal competency for speech are performed simultaneously. Pre-operative velopharyngeal endoscopy with speech assessment will define the anatomical and functional bases for velopharyngeal correction and assist in planning and tailoring the pharyngeal flap.
The dust grains flowing out of the stars are most likely non-spherical and inhomogeneous; viz. porous, fluffy and composites of many very small particles glued together. We calculate the scattering, absorption and extinction efficiencies of such composite grains. The composite grains consist of host silicate spheroid and inclusions of PAHs. We study the extinction as a function of the volume fraction of the inclusions. In particular, we study the variation in the absorption peak, at the wavelength ‘4430Å’ with the volume fraction of the PAH inclusions. We present the composite grain models and discuss the results.
Bidirectional reflectance of a surface is defined as the ratio of the scattered radiation at the detector to the incident irradiance as a function of geometry. Accurate knowledge of the bidirectional reflection function for layers composed of discrete, randomly positioned scattering particles is essential for many remote sensing, engineering, and biophysical applications, as well as for different areas of astrophysics. Computations of bidirectional reflection functions for plane parallel particulate layers are usually reduced to solving the radiative transfer equation by the existing techniques. In this work we present our laboratory data on bidirectional reflectance versus phase angle for two sample sizes of alumina, 0.3 and 1 μm, for the He–Ne laser at wavelengths of 632.8 nm (red) and 543.5 nm (green). The nature of the phase curves of the asteroids depends on the parameters like particle size, composition, porosity, roughness, etc. In the present study we analyze data which are being generated using a single scattering phase function, that is, Mie theory of treating particles as a compact sphere. The well-known Hapke formula, along with different particle phase functions such as Mie and Henyey–Greenstein, will be used to model the laboratory data obtained at the asteroid laboratory of Assam University.
The body and elytra of the diamond weevil, Entimus imperialis, is studded with numerous brightly colored scales. The scales exhibit brilliant reflections because they contain unusually large diamond-type photonic crystals. The scales are concentrated in pits on the otherwise black elytra. This framing enhances the color contrast when the weevil is observed from nearby. From a distance the diamond weevil looks green, alike green foliage. Another weevil, Eupholus cuvieri, has also scales with green reflective photonic crystals, but here the scales are arranged closely apposed on the planar elytra. Both weevils use photonic crystals for camouflage, but the display methods are different.
Radio frequency (RF) and microwave amplifier research has been largely focused on solid-state technology in recent years. This paper presents design and performance characterization of a 50-kW modular solid-state amplifier, operating at 505.8 MHz. It includes architecture selection and design procedures based on circuit and EM simulations for its building blocks like solid-state amplifier modules, combiners, dividers, and directional couplers. Key performance objectives such as efficiency, return loss, and amplitude/phase imbalance are discussed for this amplifier for real-time operation. This amplifier is serving as the state-of-the-art RF source in Indus-2 synchrotron radiation source. Characterization on component level as well as system level of this amplifier serves useful data for RF designers working in communication and particle accelerator fields.
We present the results from nearly three years of monitoring of the variations in dispersion measure (DM) along the line-of-sight to 11 millisecond pulsars using the Giant Metrewave Radio Telescope (GMRT). These results demonstrate accuracies of single epoch DM estimates of the order of 5 × 10−4 cm−3 pc. A preliminary comparison with the Parkes Pulsar Timing Array (PPTA) data shows that the measured DM fluctuations are comparable. We show effects of DM variations due to the solar wind and solar corona and compare with the existing models.
A setup is described where an individual electrospun polyamide fiber is attached to an atomic force microscope (AFM) tip and structural information collected with synchrotron micro Fourier transform infrared spectroscopy (μFT-IR). The combination of AFM and synchrotron μFT-IR therefore highlights the potential for recording structure-mechanical property relationships simultaneously in materials with sub-micron dimensions.