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To verify dose delivery and quality assurance of volumetric-modulated arc therapy (VMAT) for head and neck (H&N) cancer.
The Imaging and Radiation Oncology Core Houston (IROC-H) H&N phantom with thermoluminescent dosimeters (TLDs) and films, were imaged with computed tomography scan and the reconstructed image was transferred to pinnacle treatment planning system (TPS). On TPS, the planning target volume (PTV), secondary target volume (STV) and organ at risk (OAR) were delineated manually and a treatment plan was made. The dose constraints were determined for the concerned organs according to IROC-H prescription. The treatment plan was optimised using adoptive convolution algorithm to improve dose homogeneity and conformity. The dose calculation was performed using C.C Convolution algorithm and a Varian True Beam linear accelerator was used to deliver the treatment plan to the H&N phantom. The delivered radiation dose to the phantom was measured through TLDs and GafChromic external beam radiotherapy 2 (EBT2) films. The dosimetric performance of the VMAT delivery was studied by analysing percent dose difference, isodose line profile and gamma analysis of the TPS-computed dose and linac-delivered doses.
The percent dose difference of 3.8% was observed between the planned and measured doses of TLDs and a 1.5-mm distance to agreement (DTA) was observed by comparing isodose line profiles. Passed the gamma criteria of 3%/3 mm was with good percentages.
The dosimetric performance of VMAT delivery for a challenging H&N radiotherapy can be verified using TLDs and films embedded in an anthropomorphic H&N phantom.
Detrimental effects of ultraviolet (UV) light on living organisms are well understood, little is known about the effects of blue light irradiation. Although a recent study revealed that blue light caused more harmful effects on insects than UV light and blue light irradiation killed insect pests of various orders including Diptera, the effects of blue light on physiology of insects are still largely unknown. Here we studied the effects of blue light irradiation on cuticular melanin in larval and the immune response in adult stage of Bactrocera dorsalis. We also evaluated the effects of blue light exposure in larval stage on various age and mass at metamorphosis and the mediatory role of cuticular melanin in carryover effects of larval stressors across metamorphosis. We found that larvae exposed to blue light decreased melanin contents in their exoskeleton with smaller mass and delayed metamorphosis than insects reared without blue light exposure. Across metamorphosis, lower melanotic encapsulation response and higher susceptibility to Beauveria bassiana was detected in adults that had been exposed to blue light at their larval stage, thereby constituting the first evidence that blue light impaired adult immune function in B. dorsalis as a carryover effect of larval exposure.
This study describes the first large-scale serosurvey on West Nile virus (WNV) conducted in the equine population in Pakistan. Sera were collected from 449 equids from two provinces of Pakistan during 2012–2013. Equine serum samples were screened using a commercial ELISA kit detecting antibodies against WNV and related flaviviruses. ELISA-positive samples were further investigated using virus-specific microneutralization tests (MNTs) to identify infections with Japanese encephalitis virus (JEV), WNV and tick-borne encephalitis virus (TBEV). Anti-WNV antibodies were detected in 292 samples by ELISA (seroprevalence 65·0%) and WNV infections were confirmed in 249 animals by MNT. However, there was no animal found infected by JEV or TBEV. The detection of WNV-seropositive equines in Pakistan strongly suggests a widespread circulation of WNV in Pakistan.
Imprinting is a well-established technique to induce recognition features in both organic and inorganic materials for a variety of target analytes. In this study, ion imprinted polysiloxanes with varying percentage of coupling agent i.e. 3-chloro propyl trimethoxy silane (CPTM) were synthesized by sol-gel method for imprinting of Cr3+. The imprinting of Cr3+ in cross-linked siloxane network was investigated by FT-IR which indicates the metal ion is coordinated with oxygen atoms of polysiloxanes. SEM images revealed that imprinted polysiloxanes possess uniform particles of submicron size. It was experienced that by increasing the concentration of CPTM up to 10% (v/v) substantially improves the binding capacity of polysiloxanes which allows us to recognized Cr3+ down to 50µg/L. Furthermore, the selectivity of Cr3+-imprinted polysiloxanes was evaluated by treating them with other competing metal ions of same concentration i.e. Cr6+, Pb2+ and Ni2+. In this regard, polysiloxanes showed much higher binding for imprint ion i.e. Cr3+ in comparison to above mentioned metal ions. Finally, the regenerated polysiloxanes were studied in order to reuse them thus, developing cost effective biomimetic sensor coatings.
We present a preliminary 3D potential field extrapolation model of the joint magnetosphere of the close accreting PMS binary V4046 Sgr. The model is derived from magnetic maps obtained as part of a coordinated optical and X-ray observing program.
The prevalence of the digenean Plagiorchis sp. was investigated in a natural wood mouse population (Apodemus sylvaticus) in a periaquatic environment. Classical identification was complemented with the use of molecular differentiation to determine prevalence and verify species identity. Use of the complete ITS1-5.8S rDNA-ITS2 and partial 28S rDNA gene sequences have confirmed that the species reported at this location was Plagiorchis elegans and not Plagiorchis muris as reported previously. This underlines the difficulties in identification of these morphologically similar parasites. Plagiorchis elegans is typically a gastrointestinal parasite of avian species but has also been reported from small mammal populations. Although the occurrence of this digenean in A. sylvaticus in the UK is rare, in the area immediately surrounding Malham Tarn, Yorkshire, it had a high prevalence (23%) and a mean worm burden of 26.6 ± 61.5. The distribution of P. elegans followed a typically overdispersed pattern and both mouse age-group and sex were determined to be two main factors associated with prevalence. Male mice harboured the majority of worms, carrying 688 of 717 recovered during the study, and had a higher prevalence of 32.4% in comparison to only 8.7% in the small intestine of female mice. A higher prevalence of 43% was also observed in adult mice compared to 14% for young adults. No infection was observed in juvenile mice. These significant differences are likely to be due to differences in the foraging behaviour between the sexes and age cohorts of wood mice.
To conduct a systematic review comparing the effect of three interventions (prophylactic antibiotics, tympanostomy tube insertion and adenoidectomy) on otitis media recurrence, recurrence frequency and total recurrence time.
Literature on recurrent otitis media was identified using the PubMed and Scopus search engines for the period January 1990 to March 2011. A hand search of the reference lists of relevant articles and textbooks was conducted to identify additional studies. Randomised, controlled trials with a minimum of 40 children and follow up of at least 12 months were included.
Eighteen publications were identified. Each was assessed using preset inclusion criteria; seven publications met these criteria.
Prophylactic antibiotics are effective in reducing otitis media recurrence, recurrence frequency and total recurrence time. Tympanostomy tube insertion failed to reduce the prevalence of otitis media recurrence, but reduced the recurrence frequency and total recurrence time. Adenoidectomy reduced otitis media recurrence; results on otitis media recurrence frequency differed but on average there was a reduction; however, the two studies with relevant data on total recurrence time had contradictory results.
(1) To identify newly diagnosed cases of methicillin-resistant Staphylococcus aureus ear infection in our local population; (2) to determine the risk factors involved in these patients' clinical courses, and (3) to type the bacterial strains isolated and thus identify whether they were hospital- or community-acquired.
Design and setting:
Retrospective review of case notes, together with laboratory-based molecular studies in the departments of otolaryngology and medical microbiology in a university teaching hospital in Scotland, UK.
Over a two-year period, 35 patients were identified with ear swabs positive for methicillin-resistant Staphylococcus aureus infection. These cases came from both hospital and community settings.
Main outcome measures:
(1) Identification of primary methicillin-resistant Staphylococcus aureus otorrhoea in patients with no previously documented colonisation; and (2) molecular typing of the strains isolated, using spa technology, to identify whether they were hospital- or community-acquired.
Of the 35 positive patients, 27 were previously known carriers of methicillin-resistant Staphylococcus aureus. The eight patients with newly diagnosed methicillin-resistant Staphylococcus aureus otorrhoea presented initially in the community. All of these patients had had contact with hospital staff (as in-patients or out-patients) in the weeks preceding development of their ear infection. Using the spa technique for molecular typing, we identified hospital-acquired (‘epidemic’) methicillin-resistant Staphylococcus aureus type 15 in all eight patients' isolates. All were sensitive to topical gentamicin.
In our cohort, hospital-acquired methicillin-resistant Staphylococcus aureus type 15 was the commonest cause of methicillin-resistant Staphylococcus aureus otorrhoea, despite the fact that these patients all first presented in the community. We believe that contact with hospital staff or health care workers is a risk factor for acquiring methicillin-resistant Staphylococcus aureus otorrhoea in the community.
Depleted uranium (U
is used for pre-ionization in the neon gas to
study the soft X-ray emission in a Mather type plasma focus of 3.3 kJ. The
X-rays are detected using an assembly of Quantrad Si pin diodes, masked with
differential Ross fitters, and with a multi pinhole camera. The X-ray yield
and pinhole images are found strongly influenced by the preionization and
the pressure of the working gas. The soft X-ray yield of 82.5 ± 4.0 J in
1.3–1.56 keV energy window is obtained in the case of preionization of
neon gas at the optimum pressure of 5 mbar, leading to the conversion
efficiency of 2.5% of the stored energy. The total yield with
preionization is 195 ± 9.0 J in 4π geometry measured at the optimum
pressure of 5 mbar giving conversion efficiency of 5.9%. The time
integrated images indicate the broadening of X-ray emission zone with
There is a paucity of evidence to guide the post-operative follow up of patients undergoing middle-ear ventilation tube insertion for the first time. This study was conceived to identify current practice at our institution (Ninewells Hospital, Dundee) and to inform subsequent change in our follow-up procedure.
Two cycles of data collection and analysis were performed. All paediatric patients undergoing ventilation tube insertion for the first time were identified. Patients who had previously undergone ventilation tube insertion or additional procedures such as adenoidectomy or tonsillectomy were excluded. The first data collection period comprised all of the year 2000, and the second 18 months over 2003–2004. A minimum of 20 months' follow up was allowed for. Data regarding clinical findings and audiometry were recorded at each follow-up appointment.
We identified a total of 50 patients meeting our criteria for inclusion in the first cohort. There were a total of 156 appointments between surgery and data collection (a mean of 3.12 per child). A total of 113 (72 per cent) appointments lead to no medical intervention. The only statistically significant difference between patients requiring further ventilation tube insertion (n = 10) and those not requiring further treatment during the study period (n = 40) was the average hearing threshold (p < 0.01). These findings prompted a change in the post-operative regime; all patients undergoing ventilation tube insertion were subsequently seen at three months for a pure tone audiogram, and further review depended on clinical and audiometric findings. Records for 84 children were identified and collected for the second cohort, there were a total of 154 appointments (a mean of 1.83 per child). In only 18 appointments (12 per cent) were normal findings and hearing recorded and children given a further review appointment. Sixteen of 29 (55 per cent) children with abnormal clinical findings (otorrhoea, tube blockage or extrusion) required some form of intervention (p < 0.05). Twenty-six had a mean hearing threshold worse than 20 dB at first review. Nineteen (73 per cent) required further intervention of some sort (p < 0.01).
Our study demonstrated that the vast majority of review appointments resulted in no clinical intervention. We therefore question the need for regular follow up in this patient group. Twenty per cent (10 of 50 and 18 of 84) of our patients required further ventilation tube insertion within the study periods. This is consistent with rates reported in the literature. Children with abnormal clinical findings or a mean hearing threshold greater than 20 dB were significantly more likely to require further intervention. We would recommend one post-operative review with audiometry, three months after surgery. At this initial appointment, further review should be offered to those children with poor hearing, early extrusion, blockage or infection, as they are more likely to require further ventilation tube insertion. This strategy is dependent on good links with community primary care providers and easy access to secondary care for further management, should this be required.
Changes in environmental conditions and the EU policy have put more emphasis on growing
alternative crops in the set aside farmlands of western Europe, and sunflowers are increasingly being
grown as a minor crop in the UK. However, long-term success of sunflowers as a commercial crop
depends largely on the availability of early maturing, high yielding, disease resistant varieties. The
present study was conducted to investigate the nature of genetic variation among the available
breeding stocks that may have to be exploited to produce such cultivars. Analysis of 182 test crosses,
produced by crossing 13 male sterile (CMS) lines with 14 restorer (SB) lines, has revealed that genetic
variability exists for many important traits, including maturity, vigour and seed yield. Genetic
differences were also detected within the male sterile and restorer groups of lines even though they
were classed as early maturing. All types of gene effects, additive, dominance and epistasis,
contributed to variation among the test crosses and dominance was largely unidirectional and partial.
CMS and SB lines also showed some allelic complementation and the CMS exerted a modest degree
of maternal control for flowering time. The test crosses were generally more vigorous and high
yielding compared to their inbred parents. But they also matured significantly late, indicating that all
crosses will not be suitable as potential hybrids for the UK conditions. Genotypic correlations
indicated that faster growth, early flowering, high seed number and seed weight can be combined
more readily in the F1 crosses.
We report the design, manufacturing, and testing of a new cesium enhanced negative carbon ion source that can be useful to synthesize hard and/or electron emitting carbon nitride and diamond-like carbon (DLC) thin films. The design of the source includes a conventional magnetron-sputtering gun, low voltage ion extraction lenses, and a cesium oven to provide cesium vapor for formation of a fractional mono layer of Cs on the carbon target. Cs reduces the surface work function of the carbon target and enhances the emission of negative carbon ions. Argon and argon-nitrogen gas mixtures were used to ignite and sustain the plasma in the chamber. We compare the properties of carbon nitride and DLC films deposited with and without cesium. Nitrogen composition in the Ar-N2 gas mixture was observed to be an important process parameter affecting mechanical properties of the film. The effect of the Cs oven temperature on deposition rate and current absorbed at the substrate was also investigated for RF powers from 0 to 150 W.
Functional endoscopic sinus surgery (FESS) is an effective treatment for inflammatory sinus disease. The potential for major complications during FESS is high particularly under general anaesthesia. The most serious of these is injury to the eye leading to blindness. We looked at the feasibility of monitoring flash visual evoked potentials (VEP) simultaneously from both eyes during FESS. Five patients were included in this preliminary study. A haptic contact lens connected by fibreoptic cable to a photostimulator was placed on the eyes and stimulus of comparable intensity to a conventional strobe was delivered. We found that an increase in P100 latency to be an indicator of optic nerve compression. However, for this to be useful the diastolic blood pressure should not fall below 50 mmHg, the oxygen saturation should be maintained at 98 per cent and bleeding should be minimized during surgery. The changes in the amplitude of P100 was not found to be useful.
While there is no substitute for learning endoscopic surgery by cadaveric dissection and supervised training we believe that in selected cases VEP monitoring can be employed with profit.
Data from the F1, F2 and F3 generations derived from four F1 hybrids of sunflower were analysed to determine the genetical control of eleven agronomically important traits namely, flowering time (FT), final height (FH), seed set (SS), fresh seed weight (FSW), dry seed weight (DSW), 25-seed weight (SSW), head diameter (HD), head angle (HA), neck width (NW), Botrylis infection (BI) and percentage oil content (PO), with the objective of assessing their potential for producing superior recombinant lines. Comparisons of means revealed significant differences between the F: generations of crosses for all the characters except FT. Model fitting indicated that these differences were attributed either to variation in the magnitude of the dominance component [h], or the projected mean of the Finfin; generation, m. Further, all the variation in the generation means was accounted for by the m and [h] parameters and epistasis was shown to be non-existent for almost all the traits. Analysis of the second degree statistics revealed the presence of additive genetic effects and most of the characters showed moderate heritability except for HD, which was highly heritable. All the crosses were predicted to produce significant numbers of transgressive segregants and consequently were expected to yield superior inbred lines and second cycle hybrids either to be released as varieties as such or to be utilized in future breeding work. The overall differences between the crosses, however, were not highly pronounced and therefore it was not possible to identify a cross which would yield markedly superior recombinant lines and F1 crosses compared to the others.
Inhalation of a foreign body is a serious event. The number of foreign bodies that become impacted in the larynx is small and requires urgent recognition. We describe the case of a six-month-old baby with an impacted open safety pin in the larynx. The sharp end of the safety pin was upwards and had penetrated the anterior end of the left vocal fold. We discuss the management and describe our method of removal of the foreign body. Tracheostomy was not required in this case and the child had an uneventful recovery
A brief review of the literature is included
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