779 research outputs found
Quinsy tonsillectomy or interval tonsillectomy - a prospective randomised trial
Fifty-one patients with peritonsillar abscesses were randomised to undergo either quinsy tonsillectomy (aT) or interval tonsillectomy (IT), and the two groups were compared. The QT group lost fewer (10,3 v. 17,9) working days and less blood during the operation (158,6 ml v. 205,7 ml); haemostasis was easier and the operation was technically simpler in this group. There was no significant difference in length of hospital stay and neither group had intra- or postoperative complications. Only 64% of the IT group returned for tonsillectomy. In this study QT had distinct advantages over drainage and IT in the management of peritonsillar abscesses
Myringoplasty - effects on hearing and contributing factors
Indications for myringoplasty are chronic otorrhoea and hearing impairment. Some authors have described poor postoperative hearing results and sensorineural hearing loss associated with the surgery, and question the indication for myringoplasty on an ear with normal hearing « 25 dB). This study of 211 Consecutive myringoplasties performed over 1 year details the 'take rate,' hearing gains and losses, and factors found to influence the above. The take rate of 78% is comparable with figures in the literature. The most significant factors influencing this are the grade of the surgeon and the size of the perforation. The average pre-operative air-bone gap was closed from 23,7 dB to 13,9 dB with a 4,5% incidence of postoperative sensorineural hearing loss. Postoperatively 77,9% of patients had an air-bone gap of less than 20 dB. We conclude that myringoplasty is a beneficial procedure, closing the tympanic membrane and improving the hearing
Traceroute sampling makes random graphs appear to have power law degree distributions
The topology of the Internet has typically been measured by sampling
traceroutes, which are roughly shortest paths from sources to destinations. The
resulting measurements have been used to infer that the Internet's degree
distribution is scale-free; however, many of these measurements have relied on
sampling traceroutes from a small number of sources. It was recently argued
that sampling in this way can introduce a fundamental bias in the degree
distribution, for instance, causing random (Erdos-Renyi) graphs to appear to
have power law degree distributions. We explain this phenomenon analytically
using differential equations to model the growth of a breadth-first tree in a
random graph G(n,p=c/n) of average degree c, and show that sampling from a
single source gives an apparent power law degree distribution P(k) ~ 1/k for k
< c
Efficacy of endoscopic sinus surgery for paranasal sinus mucocele including modified endoscopic Lothrop procedure for frontal sinus mucocele
This study evaluated the efficacy of the modified endoscopic Lothrop procedure (MELP) for complicated frontal mucoceles and endoscopic marsupialization for other paranasal sinus mucoceles. It was a retrospective, consecutive case review of sinus mucoceles treated endoscopically by a single surgeon over a four-year period (1998-2002). There were 41 mucoceles in 28 patients, including 24 frontal, eight frontoethmoidal, three ethmoidal, five maxillary and one frontal mucocele. Twenty-one patients underwent the modified Lothrop procedure for frontal mucoceles, and seven underwent simple drainage and marsupialization for frontoethmoidal, ethmoidal and maxillary mucoceles. At median follow-up of 16 months, all patients had a patent mucocele opening. Patients treated by drainage and marsupialization did not have any complications or mucocele recurrence. All patients treated by the modified endoscopic Lothrop procedure had improvement in symptoms and signs. Four patients had minor complications including epistaxis and adhesions and five required further surgery. The average hospital in-patient stay was 2 ± 1.4 days. Endoscopic techniques, including MELP are effective in the short term for the management of complex and simple paranasal sinus mucoceles. MELP has a useful place in the management of mucoceles with a significant bony partition from an adjacent sinus or nasal cavity. It is also indicated when the mucocele is associated with loss of lateral support in the sinus with risk of medial-wall collapse of the orbital contents obstructing drainage.Jwu Jin Khong, Raman Malhotra, Dinesh Selva and Peter John Wormal
Proximal genomic localization of STAT1 binding and regulated transcriptional activity
BACKGROUND: Signal transducer and activator of transcription (STAT) proteins are key regulators of gene expression in response to the interferon (IFN) family of anti-viral and anti-microbial cytokines. We have examined the genomic relationship between STAT1 binding and regulated transcription using multiple tiling microarray and chromatin immunoprecipitation microarray (ChIP-chip) experiments from public repositories. RESULTS: In response to IFN-γ, STAT1 bound proximally to regions of the genome that exhibit regulated transcriptional activity. This finding was consistent between different tiling microarray platforms, and between different measures of transcriptional activity, including differential binding of RNA polymerase II, and differential mRNA transcription. Re-analysis of tiling microarray data from a recent study of IFN-γ-induced STAT1 ChIP-chip and mRNA expression revealed that STAT1 binding is tightly associated with localized mRNA transcription in response to IFN-γ. Close relationships were also apparent between STAT1 binding, STAT2 binding, and mRNA transcription in response to IFN-α. Furthermore, we found that sites of STAT1 binding within the Encyclopedia of DNA Elements (ENCODE) region are precisely correlated with sites of either enhanced or diminished binding by the RNA polymerase II complex. CONCLUSION: Together, our results indicate that STAT1 binds proximally to regions of the genome that exhibit regulated transcriptional activity. This finding establishes a generalized basis for the positioning of STAT1 binding sites within the genome, and supports a role for STAT1 in the direct recruitment of the RNA polymerase II complex to the promoters of IFN-γ-responsive genes
The role of electronic triplets and high-lying singlet states in the deactivation mechanism of the parent BODIPY: An ADC(2) and CASPT2 study
The potential tunability of the spectroscopic properties of the BODIPY parent dye by suitable functionalization makes it attractive for a number of applications. Unfortunately, its strong fluorescence against minor intersystem crossing to the triplet states prevents its application in photodynamic therapy. With the perspective of designing BODIPY derivatives with enhanced intersystem crossing, the goal of this work is two-fold: (i) investigate the main deactivation channels of the parent BODIPY following irradiation, paying particular attention to the accessibility of the triplet state potential energy surfaces, as well as the non-radiative pathways involving the second brightest more stable singlet electronic state, S2, and (ii) evaluate the performance of the computationally efficient second order algebraic-diagrammatic construction scheme for the polarization propagator, (ADC(2)) against the complete active space second-order perturbation theory (CASPT2) method. Three singlet/triplet crossings were found, all of them with small spin-orbit couplings, being the S1/T2 crossing the most plausible for the observed intersystem crossing yield. Methodologically, it is found that the ADC(2) method qualitatively reproduces the landscape of the potential energy profiles for the photophysical processes investigated; however, it systematically underestimates the energies of the stationary points and crossings of the same and different multiplicity, with the largest discrepancies found at S1/S0 crossing points. Our CASPT2 results provide a comprehensive picture of the landscape of the excited state potential energy surfaces of the parent BODIPY that might serve as a basis for the rational design of photosensitizers with a particular photophysical profileThis work has been supported by the Project CTQ2015-63997- C2 of the Ministerio de EconomĂa y Competitividad of Spain. I.C. gratefully acknowledges the âRamĂłn y Cajalâ program of the Ministerio de EconomĂa y Competitividad of Spain. M.D.V. thanks the Marie Curie Actions, within the Innovative Training Network-European Join Doctorate in Theoretical Chemistry and Computational Modelling TCCM-ITN-EJD-642294, for financial suppor
Finding long cycles in graphs
We analyze the problem of discovering long cycles inside a graph. We propose
and test two algorithms for this task. The first one is based on recent
advances in statistical mechanics and relies on a message passing procedure.
The second follows a more standard Monte Carlo Markov Chain strategy. Special
attention is devoted to Hamiltonian cycles of (non-regular) random graphs of
minimal connectivity equal to three
The early evolution of the H-free process
The H-free process, for some fixed graph H, is the random graph process
defined by starting with an empty graph on n vertices and then adding edges one
at a time, chosen uniformly at random subject to the constraint that no H
subgraph is formed. Let G be the random maximal H-free graph obtained at the
end of the process. When H is strictly 2-balanced, we show that for some c>0,
with high probability as , the minimum degree in G is at least
. This gives new lower bounds for
the Tur\'an numbers of certain bipartite graphs, such as the complete bipartite
graphs with . When H is a complete graph with we show that for some C>0, with high probability the independence number of
G is at most . This gives new lower bounds
for Ramsey numbers R(s,t) for fixed and t large. We also obtain new
bounds for the independence number of G for other graphs H, including the case
when H is a cycle. Our proofs use the differential equations method for random
graph processes to analyse the evolution of the process, and give further
information about the structure of the graphs obtained, including asymptotic
formulae for a broad class of subgraph extension variables.Comment: 36 page
Quilting sutures for nasal septum
Suturing of the nasal septum after septal surgery is a commonly performed procedure designed to prevent complications such as septal haematoma and bleeding. It is also useful for closing any inadvertent tears of the septal mucosa and providing additional support for the cartilage pieces retained in septoplasty. In addition, the suture can be placed through the middle turbinates, stabilising them during the healing process. Placing knots for interrupted sutures in the posterior and middle part of the nasal septum can be technically difficult. We describe a continuous suturing technique for approximating the mucosal flaps following septal surgery.C Hari, C Marnane and P J Wormal
- âŠ