603 research outputs found
Nasal packing and stenting
Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue
Attenuated and Nonproductive Viral Transcription in the Lymphatic Tissue of HIV-1-Infected Patients Receiving Potent Antiretroviral Therapy
Human immunodeficiency virus type 1 (HIV-1) RNA that persists in the lymphoid tissue of patients despite treatment with highly active antiretroviral therapy (HAART) may represent extracellular virions or intracellular RNAs residing within HIV-infected cells. To further characterize residual viral transcription, tonsil biopsy specimens from patients receiving long-term HAART, untreated patients, and patients undergoing 2 weeks of structured treatment interruption were analyzed by polymerase chain reaction quantification of virion-encapsidated RNA, intracellular unspliced HIV RNA (HIV UsRNA), multiply spliced HIV RNA encoding tat and rev (HIV MsRNA), and HIV DNA. Tonsil biopsy specimens from viremic patients harbored high amounts of virions, which primarily stemmed from local production, as indicated by a strong correlation of extracellular tonsillar RNA with intracellular HIV-1 nucleic acid levels but not with plasma viremia, and as shown by phylogenetic analysis of clonal env sequences from lymphoid tissue and plasma. In patients receiving HAART, intracellular HIV UsRNA persisted at significantly decreased levels, whereas HIV MsRNA and lymphoid virion levels were depleted. Thus, residual lymphoid HIV-1 RNA in patients receiving HAART indicates attenuated viral transcription in HIV-1-infected cells that lack virion productio
Correlation between case mix index and antibiotic use in hospitals
Background To compare the quantitative antibiotic use between hospitals or hospital units and to explore differences, adjustment for severity of illness of hospitalized patients is essential. The case mix index (CMI) is an economic surrogate marker (i.e. the total cost weights of all inpatients per a defined time period divided by the number of admissions) to describe the average patients' morbidity of individual hospitals. We aimed to investigate the correlation between CMI and hospital antibiotic use. Methods We used weighted linear regression analysis to evaluate the correlation between in-hospital antibiotic use in 2006 and CMI of 18 departments of the tertiary care University Hospital Zurich and of 10 primary and 2 secondary acute care hospitals in the Canton of Zurich in Switzerland. Results Antibiotic use varied substantially between different departments of the university hospital [defined daily doses (DDD)/100 bed-days, 68.04; range, 20.97-323.37] and between primary and secondary care hospitals (range of DDD/100 bed-days, 15.45-57.05). Antibiotic use of university hospital departments and the different hospitals, respectively, correlated with CMI when calculated in DDD/100 bed-days [coefficient of determination (R2), 0.57 (P = 0.0002) and 0.46 (P = 0.0065)], as well as when calculated in DDD/100 admissions [R2, 0.48 (P = 0.0008) and 0.85 (P < 0.0001), respectively]. Conclusions Antibiotic use correlated with CMI across various specialties of a university hospital and across different acute care hospitals. For benchmarking antibiotic use within and across hospitals, adjustment for CMI may be a useful tool in order to take into account the differences in hospital category and patients' morbiditie
Source attribution of poly- and perfluoroalkyl substances (PFASs) in surface waters from Rhode Island and the New York Metropolitan Area
Exposure to poly- and perfluoroalkyl substances (PFASs) has been associated with adverse health effects in humans and wildlife. Understanding pollution sources is essential for environmental regulation, but source attribution for PFASs has been confounded by limited information about industrial releases and rapid changes in chemical production. Here we use principal component analysis (PCA), hierarchical clustering, and geospatial analysis to understand source contributions to 14 PFASs measured across 37 sites in the northeastern United States in 2014. PFASs are significantly elevated in urban areas compared to rural sites except for perfluorobutanesulfonate, N-methyl perfluorooctanesulfonamidoacetic acid, perfluoroundecanate, and perfluorododecanate. The highest PFAS concentrations across sites were those of perfluorooctanate (PFOA, 56 ng L−1) and perfluorohexanesulfonate (PFHxS, 43 ng L−1), and perfluorooctanesulfonate (PFOS) levels are lower than earlier measurements of U.S. surface waters. PCA and cluster analysis indicate three main statistical groupings of PFASs. Geospatial analysis of watersheds reveals the first component/cluster originates from a mixture of contemporary point sources such as airports and textile mills. Atmospheric sources from the waste sector are consistent with the second component, and the metal smelting industry plausibly explains the third component. We find this source-attribution technique is effective for better understanding PFAS sources in urban areas
Positive In Vivo Selection of the HIV-1 Envelope Protein gp120 Occurs at Surface-Exposed Regions
The rapid evolution of human immunodeficiency virus (HIV) envelope represents a major challenge to vaccine and drug development, particularly because the underlying mechanisms are not completely understood. To explore whether distinct patterns of positive selection within the envelope protein glycoprotein (gp) 120 exist and are associated with functionally relevant domains, we conducted a long-term survey of sequence evolution in 20 HIV-1-infected persons who interrupted antiretroviral therapy. In total, 1753 clonal sequences encompassing the C2-V3-C3 region of gp120 were derived. Strikingly, positively selected amino acids mapped almost exclusively (P=.0003) to externally accessible residues on the gp120 crystal structure. The current understanding of envelope structure and function associates the main determinants of viral entry and the targets for neutralizing antibodies with these exterior regions of gp120, strongly suggesting that the observed adaptive evolution of these sites occurs in response to respective selective force
Reconstruction of the Exenterated Orbit with an Island Pericranial Flap: A New Surgical Approach
Background:
Reconstruction of the bony socket after orbital exenteration is a matter of much debate. Prompt defect closure with a microvascular flap is desirable but involves a major surgical procedure and hence, places considerable burden on the patient. The new surgical technique presented here permits a technically simpler wound closure with fewer complications after orbital exenteration.
Methods:
Between May 2014 and June 2022 in the ENT department of Regensburg University, nine patients underwent exenteration and reconstruction with a pericranial flap. The flap was raised via a broken line incision in the forehead or endoscopically, incised in a roughly croissant-like shape, then introduced into the orbit through a tunnel in the eyebrow. A retrospective analysis of the patients and considerations about determining the size, shape, and vascular supply of the flap are presented.
Results:
Flap healing was uncomplicated in all cases. Only 6 weeks after surgery, the flap was stable, making it possible to start adjuvant therapy and prosthetic rehabilitation swiftly. The flap is adapted to the near cone-shape of the orbit. The mean (± standard deviation) surface area of the measured orbits is (39.58 ± 3.32) cm2. The territory of the angular artery provides the periosteal flap arterial blood supply. Venous drainage is via venous networks surrounding the artery.
Conclusions:
Use of the pericranial flap makes it possible to close the orbital cavity promptly with minimal donor site defect and a short operating time, thereby minimizing the surgical risk and speeding up physical and psychological recovery
Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE
Ultra high fields (7T and above) allow functional imaging with high contrast-to-noise ratios and improved spatial resolution. This, along with improved hardware and imaging techniques, allow investigating columnar and laminar functional responses. Using gradient-echo (GE) (T2* weighted) based sequences, layer specific responses have been recorded from human (and animal) primary visual areas. However, their increased sensitivity to large surface veins potentially clouds detecting and interpreting layer specific responses. Conversely, spin-echo (SE) (T2 weighted) sequences are less sensitive to large veins and have been used to map cortical columns in humans. T2 weighted 3D GRASE with inner volume selection provides high isotropic resolution over extended volumes, overcoming some of the many technical limitations of conventional 2D SE-EPI, whereby making layer specific investigations feasible. Further, the demonstration of columnar level specificity with 3D GRASE, despite contributions from both stimulated echoes and conventional T2 contrast, has made it an attractive alternative over 2D SE-EPI. Here, we assess the spatial specificity of cortical depth dependent 3D GRASE functional responses in human V1 and hMT by comparing it to GE responses. In doing so we demonstrate that 3D GRASE is less sensitive to contributions from large veins in superficial layers, while showing increased specificity (functional tuning) throughout the cortex compared to GE
CoRoT high-precision photometry of the B0.5 IV star HD 51756
OB stars are important constituents for the ecology of the Universe, and
there are only a few studies on their pulsational properties detailed enough to
provide important feedback on current evolutionary models. Our goal is to
analyse and interpret the behaviour present in the CoRoT light curve of the
B0.5 IV star HD 51756 observed during the second long run of the space mission,
and to determine the fundamental stellar parameters from ground-based
spectroscopy gathered with the CORALIE and HARPS instruments after checking for
signs of variability and binarity, thus making a step further in mapping the
top of the Beta Cep instability strip. We compare the newly obtained
high-resolution spectra with synthetic spectra of late O-type and early B-type
stars computed on a grid of stellar parameters. We match the results with
evolutionary tracks to estimate stellar parameters. We use various time series
analysis tools to explore the nature of the variations present in the light
curve. Additional calculations are carried out based on distance and historical
position measurements of the components to impose constraints on the binary
orbit. We find that HD 51756 is a wide binary with both a slow (v sin i \approx
28 km s^-1) and a fast (v sin i \approx 170 km s^-1) early-B rotator whose
atmospheric parameters are similar (T_eff \approx 30000 K and log g \approx
3.75). We are unable to detect pulsation in any of the components, and we
interpret the harmonic structure in the frequency spectrum as sign of
rotational modulation, which is compatible with the observed and deduced
stellar parameters of both components. The non-detection of pulsation modes
provides a feedback on the theoretical treatment, given that non-adiabatic
computations applied to appropriate stellar models predict the excitation of
both pressure and gravity modes for the fundamental parameters of this star.Comment: Accepted for publication in Astronomy and Astrophysics on 14/01/2011,
11 pages, 9 figures, 4 table
Conversion of self-assembled monolayers into nanocrystalline graphene: Structure and electric transport
Graphene-based materials have been suggested for applications ranging from
nanoelectronics to nanobiotechnology. However, the realization of
graphene-based technologies will require large quantities of free-standing
two-dimensional (2D) carbon materials with tuneable physical and chemical
properties. Bottom-up approaches via molecular self-assembly have great
potential to fulfil this demand. Here, we report on the fabrication and
characterization of graphene made by electron-radiation induced cross-linking
of aromatic self-assembled monolayers (SAMs) and their subsequent annealing. In
this process, the SAM is converted into a nanocrystalline graphene sheet with
well defined thickness and arbitrary dimensions. Electric transport data
demonstrate that this transformation is accompanied by an insulator to metal
transition that can be utilized to control electrical properties such as
conductivity, electron mobility and ambipolar electric field effect of the
fabricated graphene sheets. The suggested route opens broad prospects towards
the engineering of free-standing 2D carbon materials with tuneable properties
on various solid substrates and on holey substrates as suspended membranes.Comment: 30 pages, 5 figure
Different Patterns of Inappropriate Antimicrobial Use in Surgical and Medical Units at a Tertiary Care Hospital in Switzerland: A Prevalence Survey
Audits of individual patient care provide important data to identify local problems in antimicrobial prescription practice. In our study, antimicrobial prescriptions without indication, and divergence from institutional guidelines were frequent errors. Based on these results, we will tailor education, amend institutional guidelines and further develop the infectious diseases consultation service
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