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Patients with advanced otosclerosis can present with hearing thresholds eligible for cochlear implantation. This study sought to address whether stapes surgery in this patient group provides a clinically significant audiological benefit.
To assess pre- and post-operative hearing outcomes of patients with advanced otosclerosis, and to determine what proportion of these patients required further surgery including cochlear implantation.
Between 2002 and 2015, 252 patients underwent primary stapes surgery at our institution. Twenty-eight ears in 25 patients were deemed to have advanced otosclerosis, as defined by pure audiometry thresholds over 80 dB. The patients’ records were analysed to determine audiological improvement following stapes surgery, and assess whether any further surgery was required.
The audiological outcome for most patients who underwent primary stapes surgery was good. A minority of patients (7 per cent) required revision surgery. Patients who underwent cochlear implantation after stapes surgery (10 per cent) also demonstrated a good audiological outcome.
Stapes surgery is a suitable treatment option for patients with advanced otosclerosis, and should be considered mandatory, before offering cochlear implantation, for those with a demonstrable conductive component to their hearing loss. A small group of patients get little benefit from surgery and subsequently a cochlear implant should be considered.
To determine the impact of total household decolonization with intranasal mupirocin and chlorhexidine gluconate body wash on recurrent methicillin-resistant Staphylococcus aureus (MRSA) infection among subjects with MRSA skin and soft-tissue infection.
Three-arm nonmasked randomized controlled trial.
Five academic medical centers in Southeastern Pennsylvania.
Adults and children presenting to ambulatory care settings with community-onset MRSA skin and soft-tissue infection (ie, index cases) and their household members.
Enrolled households were randomized to 1 of 3 intervention groups: (1) education on routine hygiene measures, (2) education plus decolonization without reminders (intranasal mupirocin ointment twice daily for 7 days and chlorhexidine gluconate on the first and last day), or (3) education plus decolonization with reminders, where subjects received daily telephone call or text message reminders.
MAIN OUTCOME MEASURES
Owing to small numbers of recurrent infections, this analysis focused on time to clearance of colonization in the index case.
Of 223 households, 73 were randomized to education-only, 76 to decolonization without reminders, 74 to decolonization with reminders. There was no significant difference in time to clearance of colonization between the education-only and decolonization groups (log-rank P=.768). In secondary analyses, compliance with decolonization was associated with decreased time to clearance (P=.018).
Total household decolonization did not result in decreased time to clearance of MRSA colonization among adults and children with MRSA skin and soft-tissue infection. However, subjects who were compliant with the protocol had more rapid clearance
To identify risk factors for recurrent methicillin-resistant Staphylococcus aureus (MRSA) colonization.
Prospective cohort study conducted from January 1, 2010, through December 31, 2012.
Five adult and pediatric academic medical centers.
Subjects (ie, index cases) who presented with acute community-onset MRSA skin and soft-tissue infection.
Index cases and all household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as 2 consecutive sampling periods with negative surveillance cultures. Recurrent colonization was defined as any positive MRSA surveillance culture after clearance. Index cases with recurrent MRSA colonization were compared with those without recurrence on the basis of antibiotic exposure, household demographic characteristics, and presence of MRSA colonization in household members.
The study cohort comprised 195 index cases; recurrent MRSA colonization occurred in 85 (43.6%). Median time to recurrence was 53 days (interquartile range, 36–84 days). Treatment with clindamycin was associated with lower risk of recurrence (odds ratio, 0.52; 95% CI, 0.29–0.93). Higher percentage of household members younger than 18 was associated with increased risk of recurrence (odds ratio, 1.01; 95% CI, 1.00–1.02). The association between MRSA colonization in household members and recurrent colonization in index cases did not reach statistical significance in primary analyses.
A large proportion of patients initially presenting with MRSA skin and soft-tissue infection will have recurrent colonization after clearance. The reduced rate of recurrent colonization associated with clindamycin may indicate a unique role for this antibiotic in the treatment of such infection.
Infect. Control Hosp. Epidemiol. 2015;36(7):786–793
To determine the implications of a functional approach to vestibular schwannoma surgery, with facial nerve function prioritised higher than total tumour excision.
A case–control study in a tertiary referral neurotology clinic.
A ‘functional’ surgical group treated after April 2007 (n = 44, mean cerebellopontine angle dimension 27 mm), and an ‘excisional’ surgical group matched for tumour size, treated from 1997 to April 2007 (n = 115).
Facial nerve preservation: 77 per cent House–Brackmann grade I–II in functional group at 12 months, versus 57 per cent grade I–II in excisional group (p = 0.027). Tumour recurrence: 1 per cent in total excision group, 2 per cent in near-total group and 40 per cent in sub-total group.
A functional approach to vestibular schwannoma surgery improves facial nerve preservation outcomes and reduces the requirement for facial nerve rehabilitative interventions. Tumour recurrence rates are low in near-totally excised lesions but significant if only sub-total excision is achieved.
We studied a cross-sectional sample of the population of Kech, a small rural town in Pakistan to determine the prevalence and risk factors for hepatitis C infection. The prevalence of hepatitis C was 110 out of 2000 persons (5·5%, 95% confidence interval 4·5–6·5). Higher rates were identified in males. Independent risk factors identified were age ⩾75 years, being a healthcare worker, and injecting drug use. There was a high prevalence of many potential routes of transmission of bloodborne viruses and most people reported at least one potential risk factor.
This paper reports on a study of the nucleation phase of thin film growth during pyrolytic deposition by direct-laser writing. A Monte Carlo computer simulation is used to model the initial surface dynamics occurring during the deposition of silicon from silane (SiH4) on strongly binding substrates such as silicon, and on weakly binding substrates such as silicon dioxide (SiO2) and silicon nitride (Si3N4). Results show that for high peak temperatures (≥ 1200 K) and weakly binding substrates, the most probable location for the initiation of thin film growth is radialy displaced from the center of the locally laser-heated region of the surface. At low peak temperatures, thin film nucleation is found to begin at the center of the locally laser-heated surface for all substrates.
Optical probing of laser-assisted chemical reactions on surfaces in real time can help explain and control these processes. Raman microprobe spectroscopy and micro laser induced fluorescence are the two optical probes employed here to investigate several examples of localized laser surface reactions. Raman microprobe analysis is used to monitor in real time the CuCl and CuCl2 products on the surface during local laser etching of copper films by Cl2 and the concomitant loss of the Cu2O passivation layer. It is also used to follow the production of Cu2O during the laser oxidation of Cu. Polarization Raman analysis is utilized to identify and analyze partially molten silicon during laser heating in vacuum and during the etching of silicon by chlorine. Laser induced fluorescence is used as a real time microprobe of desorbed products during local laser-assisted etching of Si and Al surfaces.
This paper reports initial results of an experimental study of the early stages of silicon thin film growth on well prepared (100) c-Si surfaces by pyrolytic deposition from silane (SiH4) during localized laser chemical vapor deposition (LLCVD). The rate of silicon thin film growth during low pressure (< 10 Torr) deposition using tightly focussed laser beams (514.5 nm, ∼ 2.5 μm FWHM) is characterized and is shown to be much slower than expected based on the previously measured silane decomposition rate. Hybrid-heating experiments, in which laser heating induces a slight temperature increase on a uniformly heated substrate in the presence of silane gas, shows that growth is inhibited within the laser irradiation region. This result suggests that a nonpyrolytic mechanism contributes to silicon growth in laser CVD. Possible explanations for this nonpyrolytic growth mechanism are discussed.
Temperatures of laser-heated silicon microstructures on fused silica were determined by Stokes/anti-Stokes scattering using the 4880Å and 5145Å argon-ion laser lines, either separately or together to heat and probe the structure. Phonon shifts and broadening gave consistent measurements of temperature. Evaluation of temperatures from the ratio of Stokes/anti-Stokes intensities was shown to be sensitive to the details of scattering, collection, and detection.
The rate of many processes, including the diffusion of water into rhyolitic volcanic glass (obsidian), as well as the racemization of amino acids is temperature dependent, and a knowledge of temperatures integrated over time periods of at least a year is necessary to quantify these processes. The construction and properties of simple devices consisting of small plastic containers that change weight at a rate that is a function of temperature and the activity of water will be described. The cells function because water diffuses through the plastic across a constant vapor-pressure gradient. This vapor-pressure gradient is maintained constant between the substances within the cell and the materials outside the cell. The plastic cells are usually filled with water and surrounded by a dehydrating agent, such as silica gel. A better arrangement is to fill the cell with a mixture of solid sodium chloride (NaCl) and a saturated solution of NaCl, and to surround the cell with pure water. A number of plastics have been investigated, including polycarbonate, polystyrene, tefzel, polyallomer, and methacrylate. The cells have been sealed by various methods including screw caps, room-temperature vulcanizingsilicone rubber sealant, and rubber stoppers. The final design consists of a small cell made of a polycarbonate plastic centrifuge tube containing solid NaCl plus NaCl-saturated solution sealed with a rubber stopper and placed in a polypropylene tube containing pure water. Our aim has been to develop cells that are sufficiently sensitive to yield a precision of ±0.2° C when exposed for one year at temperatures that range from 0° to 40°, and that will fit into metal fittings that can be screwed into standard 3/4-inch plastic water pipe (approximately 1 inch outside diameter).
The stresses and strains induced in thermal laser processing of substrates and thin films on substrates, are obtained in terms of single integrals by solving the thermoelastic equations using a Gaussian profile laser as the heating source. This analysis is applied to silicon thin films on fused silica and sapphire substrates. In part, this study shows that defects can form in the films because the stresses induced during high temperature laser processing of silicon and similar materials can exceed the yield stress under certain experimental conditions.
The effects of strain and confinement on optical phonons in a Si12Ge4 strained layer superlattice grown by MBE on c-Si (001) were studied as a function of hydrostatic pressure (T = 295 K) using Raman scattering. The change of phonon frequency with pressure, dω/dP, for the principal quasi-confined LO mode in the Ge layers is found to be significantly smaller than that for bulk crystalline Ge because the magnitude of biaxial strain decreases in the Ge layers with added pressure and because the Grüneisen parameter of the confined mode is smaller than that of the Γ-point optical phonon. More generally, it is noted that the magnitude of biaxial strain in many strained layer superlattices initially decreases with the application of hydrostatic pressure, making the structures more stable.
A focused argon ion laser was used to induce local thermal etching of copper films in the presence of chlorine gas. Raman scattering was used to follow the transformation of the copper film in situ to CuC1 and CuCl2. In some regimes the laser only induced transformation of copper to copper chloride, while in others the laser produced copper chloride and also desorbed it.
A phenomenological lattice dynamics model has been developed that describes how strain affects phonon frequencies and elastic constants in Group IV and III-V semiconductor thin films and strained layers. Using this model, the phonon dispersion relations for strained-layer heterostructures of Ge and GaAs on Si have been obtained in the quasiharmonic approximation. This model uses available experimental data and can predict the effect of arbitrary strains on thin films.