To test theoretical assumptions supporting the use of near-infrared spectroscopy (NIRS) in clinical practice, we examined the behaviour of NIR light transmission and attenuation in the human head. ...Sterile probes for emitting and detecting NIR light at a fixed separation of 40 mm were placed in turn on intact skin, skull, dura and cerebral cortex of 10 patients undergoing elective neurosurgery. In the first five patients, the detecting probe was moved through successive extracerebral layers with the emitter on the skin surface. In the second five patients, the process was reversed, with the emitting probe moved and the detector in the same place on the scalp. NIR intensity was measured at each tissue interface and compared with the intensity measured at the skin surface with all layers intact. Removal of bone and dura from the light path caused a significant reduction in detected intensity. The largest mean reduction in light intensity was a 14-fold decrease with removal of bone (unadjusted P < 0.0001; paired t test). The assumptions that extracerebral tissues contribute little to attenuation of NIR light in the adult head and that most of this attenuation occurs superficially in the scalp are drawn into question by this study. We postulate that the skull and/or its interface with other layers may act as an optical 'channel', distorting the behaviour of NIR light in the human head.
We studied the impact of introducing percutaneous tracheostomy to our intensive care unit on the incidence and timing of tracheostomy and on the implications for surgical training. The proportion of ...patients receiving intensive care who underwent tracheostomy doubled from a median of 8.5% to 16.8% (p < 0.01) following the introduction of the percutaneous technique with the procedure being undertaken significantly earlier during the intensive care stay. The opportunity for surgical trainees to gain experience in open surgical tracheostomy has been virtually lost. The increase in tracheostomy rate may reflect a previous under‐utilisation caused by the logistic problems of transferring a critically ill patient to theatre, or alternatively a relaxation of the indications for tracheostomy caused by a perceived benefit for the patient. An increased workload may also have contributed to the rise. Surgical trainees should be encouraged to learn percutaneous techniques and training opportunities in open surgical techniques should be maximised.
A novel Schiff base ligand N, N′-bis (1-(thiophen-2-yl) ethylidene) pyridine-2, 6-diamine has been prepared by the condensation of 2,6-diaminopyridine and 2- acetylthiophene in ethanol in the molar ...ratio of 1:2. The Study by analytical and spectroscopic techniques indicated that the complexes have composition with the general formulae: MLX2· nH2O, where (M = Mn, Co, Ni, and Cu; X = Cl; n = 4, 6, 6, 2), respectively. All the metal (II) complexes have been characterized with elemental analysis, FT−IR, Mass, 1H NMR, UV–Vis, magnetic moment, thermal analysis (TG and DTG) techniques, molar conductance and fluorescence spectra. Non electrolyte of complexes using DMF as a solvent is due to their low molar conductance. From FTIR spectral data, the coordination between the central metal ion with azomethine nitrogen and sulfur of acetylthiophene ring are confirmed. An octahedral geometry of all metal(II) complexes is investigated from electronic and magnetic data. The kinetic analysis of the thermogravimetric data was performed by using the Coats-Redfern equation. The fluorescence properties of theses complexes in DMSO, DMF, and CH3CN were studied. The effect of pH influencing the fluorescence intensity is discussed. The catalytic activities of metal(II) complexes were studied using H2O2 solution.
Effect of pH and solvent on novel bis Schiff base ligand L. Display omitted
•The analytical and spectroscopic data suggest the formula of the complexes as MLX2. nH2O.•Magnetic, electronic spectral studies show that the complexes exhibit an octahedral geometry.•The thermal behavior and kinetic parameters are determined using Coats-Redfern method.•Fluorescence spectra of ligand and its complexes were investigated in various solvent.•All the complexes catalyze the decomposition of H2O2.
We have previously shown that eating disorders are a compulsive behaviour disease, characterized by frequent recall of anorexic thoughts. Evidence suggests that memory is a neocortical neuronal ...network, excitation of which involves the hippocampus, with recall occurring by re-excitement of the same specific network. Excitement of the hippocampus by glutamate-NMDA receptors, leading to long-term potentiation (LTP), can be blocked by ketamine. Continuous block of LTP prevents new memory formation but does not affect previous memories. Opioid antagonists prevent loss of consciousness with ketamine but do not prevent the block of LTP. We used infusions of 20 mg per hour ketamine for 10 h with 20 mg twice daily nalmefene as opioid antagonist to treat 15 patients with a long history of eating disorder, all of whom were chronic and resistant to several other forms of treatment. Nine (responders) showed prolonged remission when treated with two to nine ketamine infusions at intervals of 5 days to 3 weeks. Clinical response was associated with a significant decrease in Compulsion score: before ketamine, mean +/- SE was 44.0 +/- 2.5; after ketamine, 27.0 +/- 3.5 (t test, p = 0.0016). In six patients (non-responders) the score was: before ketamine, 42.8 +/- 3.7; after ketamine, 44.8 +/- 3.1. There was no significant response to at least five ketamine treatments, perhaps because the compulsive drive was re-established too soon after the infusion, or because the dose of opioid antagonist, nalmefene, was too low.
We studied 41 patients who had previously undergone percutaneous dilational tracheostomy at least 6 months following tracheal decannulation. The patients were examined using laryngotracheoscopy and ...spirometry to assess the long-term anatomical and functional consequences of percutaneous dilational tracheostomy. Apart from one patient who had requested a scar revision, no patient was symptomatic. A significant (> 10%) tracheal stenosis was identified in four asymptomatic patients, two of whom also had spirometric evidence of this obstruction. These results suggest that the long-term outcome after percutaneous tracheostomy is at least as good as that following conventional surgical tracheostomy. Refinements of the percutaneous technique, such as endoscopic guidance, may further improve the results.
This study uses glass substrates to create nanostructured TiO2 thin films employing SolGel method. Afterwards, TiO2 films are annealed in air for two hours at (400, 450, and 500) °C. The XRD tests ...demonstrate that all films are tetragonal polycrystalline and have orientations equal to those described in the literature. These findings suggest that when the annealing temperature rises, grain size increases. As the annealing temperature is raised, the Full Width at Half Maximum (FWHM) reduces from 0.57° to 0.0.51°, and the dislocation density drops from 45.22 to 39.22.18 nm, respectively. AFM has examined the thin films' surface morphology. The films formed using this method have good crystalline and homogenous surfaces, according to AFM tests. With an increase in annealing temperature, thin films' average particle size, average roughness, and Root Mean Square (RMS) value all drop. The films' optical characteristics. The transmission was over 97% decreased with increasing annealing temperatures. It is found that the band gap decreases from 3.42 to 3.3 eV with increasing annealing temperature. Between 300 and 900 nm, the films' refractive indices range from 2.89 to 2.2.76. With higher annealing temperatures, the films' extinction coefficients fall.
The continuous progress in magnetic sensor research provides increasing accuracy in measurement systems based on magnetic sensor arrays. Many industrial applications in the field of protection for ...low-voltage electrical systems require novel technologies of AC current sensors characterized by lower costs and wider measuring range in amplitude and frequency. For this purpose, a promising solution is the utilization of sensor arrays provided with signal processing techniques. In the paper, we propose a new principle for simultaneous measurement of polyphase currents flowing in parallel conductors of arbitrary cross-sections based on processing magnetic sensor signals. After describing the analytical solution of the measurement problem, theoretical uncertainty analysis is carried out. Preliminary experimental results confirm the validity of the new approach.
MspA has been identified as a promising candidate protein as a component of a nanopore-based DNA-sequencing device. However the wildtype protein must be engineered to incorporate all of the features ...desirable for an accurate and efficient device. In the present study we have utilized atomistic molecular dynamics to perform umbrella-sampling calculations to calculate the potential of mean force (PMF) profiles for translocation of the four DNA nucleotides through MspA. We show there is an energetic barrier to translocation of individual nucleotides through a mutant that closely resembles the wildtype protein, but not through a mutant engineered for the purpose of sequencing. Crucially we are able to quantify the change in free energy for mutating key residues. Thus providing a quantitative characterisation of the energetic impact of individual amino acid sidechains on nucleotide translocation through the pore of MspA.
In these studies, radio frequency (RF) magnetron sputtering was used to produce nanostructured CuO thin films on glass bases with different thicknesses of (250, 300, and 350 nm). X-ray diffraction ...(XRD) analysis of these films revealed a polycrystalline structure with a preferred peak along the (111) plane. The Scherrer formula was used to compute the grain size. It was found that the average grain sizes are 10.78 nm, 11.36 nm, and 11.84 nm for film thicknesses of 250, 3000, and 300 nm, respectively, while the dislocation density and strain values decline. The surface roughness decreased from 9.30 nm to 4.71 nm as the thickness increased, according to atomic force microscopy (AFM) data. As the thickness of the film grew, the root mean square (RMS) roughness likewise decreased from 9.18 nm to 4.29 nm. The homogenous, semi-spherical structure comprises uniformly distributed particles, as demonstrated by SEM images. The optical properties of the grown films showed that the absorption coefficient considerably increased with film thickness. Transmittance, band gap, refractive index, and extinction coefficient all decrease with increasing film thickness. The hydrogen gas measurements, indicated a reduction in sensitivity as the thickness and gas concentration increased at 30°C.
PDF
