Please note, due to essential maintenance online transactions will not be possible between 02:30 and 04:00 BST, on Tuesday 17th September 2019 (22:30-00:00 EDT, 17 Sep, 2019). We apologise for any inconvenience.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Silicon-On-Insulator (SOI) and advanced device technologies require the ability to fabricate uniform thin films of silicon (< 50 nm) and silicon dioxide (< 5 nm). A technique for hyper-thinning silicon and silicon dioxide films to these dimensions is described. The method is based upon etching by a high flux beam of hyperthermal (2 to 14 eV translational energy) fluorine atoms generated using Physical Sciences’ FAST technology. The fluorine atom beam contains greater than 95% atoms and less than 0.1% ions. The low ion content of the beam allows damage-free processing of these films. At the available translational energies, the fluorine atom reaction probability with silicon is near unity. Hence, high rate etching can be achieved. Silicon films have been thinned at ambient temperature (20 C) to thicknesses less than 50 nm by this technique with etching rates up to 120 nm/min demonstrated. The hyperthinning is uniform and does not affect the surface finish. Analysis of the processed surface shows no evidence of contamination from the treatment. High rate etching of silicon dioxide films has also been shown. The reaction probability of hyperthermal fluorine atoms with SiO2 films is 0.25.
Statins reduce cardiovascular mortality and related risks associated with pneumonia suggesting potentially beneficial use in influenza pandemics. We investigated the effect of current statin use on acute respiratory infections in primary care. Data from anonymized electronic medical records of persons aged ⩾45 years were examined for statin use, chronic morbidity, respiratory diagnoses, vaccination procedures, and immune suppression. Logistic regression models were used to calculate odds ratios (ORs) for statin users vs. non-users in respiratory infection outcomes. A total of 329 881 person-year observations included 18% statin users and 46% influenza vaccinees. Adjusted ORs for statin users vs. non-users were: influenza-like illness, 1·05 (95% CI 0·92–1·20); acute bronchitis, 1·08 (95% CI 1·01–1·15); pneumonia, 0·91 (95% CI 0·73–1·13); all acute respiratory infections, 1·03 (95% CI 0·98–1·07); and urinary tract infections, 0·91 (95% CI 0·85–0·98). We found no benefit in respiratory infection outcomes attributable to statin use, although uniformly higher ORs in non-vaccinated statin users might suggest synergism between statins and influenza vaccination.
Many of the porous materials used in laboratory and industrial processes do not have simple regular or crystalline structures. This greatly complicates efforts to characterize them and to understand and optimize their performance for particular applications. This review surveys recent efforts to use simulation and modeling to better understand the structure and performance of several classes of materials, including phase-separated glasses, sol-gel–derived materials, templated silica materials, and activated carbons. Approaches to modeling these materials fall generally into two classes: reconstructions, which generate models based on experimental measurements, and mimetic simulations, which attempt to model the preparation of the materials. While significant progress has been made in many respects, both reconstructive and mimetic transferred currently available are often computationally intensive and not easily transferable between different classes of materials. Finally, since gas adsorption is used widely as a characterization tool for amorphous porous materials and is often the focus of the materials' application, recent developments in simulation and theory appropriate to the study of capillary phenomena in amorphous porous materials are reviewed.
This study examined the impact of meteorological conditions on sporadic, community-acquired cases of Legionnaires' disease in England and Wales (2003–2006), with reference to the 2006 increase in cases. A case-crossover methodology compared each case with self-controlled data using a conditional logistic regression analysis. Effect modification by quarter and year was explored. In total, 674 cases were entered into the dataset and two meteorological variables were selected for study based on preliminary analyses: relative humidity during a case's incubation period, and temperature during the 10–14 weeks preceding onset. For the quarter July–September there was strong evidence to suggest a year, humidity and temperature interaction (Wald χ2=30·59, 3 d.f., P<0·0001). These findings have implications for future case numbers and resource requirements.
The European Sero-Epidemiology Network 2 (ESEN2) aimed to compare serological results of vaccine-preventable diseases across Europe. To ensure direct inter-country comparability of hepatitis A virus antibody (anti-HAV) measurements, a standardization panel of 150 sera was developed by a designated reference laboratory and tested by participating national laboratories using assays of choice; each country's results were subsequently regressed against those of the reference laboratory. Quantitatively, the assays were generally highly correlated (R2>0·90). Nevertheless, qualitative comparisons indicated that results obtained with different assays may differ despite the usage of well-established international and local standards. To a great extent standardization successfully alleviated such differences. The generated standardization equations will be used to convert national serological results into common units to enable direct international comparisons of HAV seroprevalence data. The results of this study are expected to contribute to the evaluation and potential improvement of the currently employed immunization strategies for hepatitis in Europe.
The purpose of this study was to compare the occurrence of tuberculosis (TB) and the outcome of treatment between TB patients living in urban and rural areas. Cases of TB reported from 2001 to 2003 in England and Wales were assigned to a rural or urban area classification. The outcome of interest, non-completion of treatment, was investigated to determine the odds ratio for urban vs. rural residence. The effects of age, sex, ethnicity, place of birth, time since arrival in the United Kingdom, disease site, isoniazid resistance and previous diagnosis were adjusted for by multivariable logistic regression. Crude odds ratios showed a significantly higher level of treatment non-completion in rural areas. These results became non-significant (OR 1·02, 95% CI 0·83–1·26, P=0·82) after adjusting for the confounding effects of ethnic group and age. In England and Wales residence in a rural location is not an independent determinant of TB treatment outcome failure.
Email your librarian or administrator to recommend adding this to your organisation's collection.