Cost-effectiveness Analysis of Hospital Infection Control Response to an Epidemic Respiratory Virus Threat

Pandemic (H1N1) 2009 can be contained with less expensive measures than some other viruses

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Deposition and characterization of carbon thin films by varying substrate bias and temperature

The carbon film composition in terms of sp2 or sp3 can differs by varying different deposition techniques and/or parameters. In this project, Filtered Cathodic Vacuum Arc (FCVA) deposition technique is used while in-situ substrate bias and temperature are being varied. For substrate bias, there may be two completing factors associated to it. One is solely the substrate bias itself which affects the ion energy. Another is substrate heating effect which comes into play when the applied bias is high enough to generate sufficient thermal energy to heat up the substrate. Hence it is important to verify and understand the impact of substrate heating on the properties of carbon film. Results here have shown that substrate heating effect occurs at high bias of -300V. For substrate temperature, it is known that there is a phase change from a low sp2 to high sp2 carbon film when being subjected to high temperature. Carbon atoms gain enough energy to relieve stress and this creates alignment in a preferred orientation. This form of carbon film is known as Vertically Orientated Carbon (VOC). Thus it is important to identify the temperature that is required for the transition. Results here have shown that the transition point is located at a temperature beyond 300°C.Bachelor of Engineerin

Development of two-dimensional transition metal dichalcogenides for electronic and optoelectronic applications

This thesis presents research work on transition metal dichalcogenides (TMDCs), a promising class of 2D materials in the post-graphene era. TMDCs are in the form of X-M-X, where M is a transition metal element from groups 4-7 and group 10 and X is a chalcogen (S, Se or Te). Due to the vast number of possible combinations, more than over 40 members can exist in the TDMC family. Here, only two of the members – MoS2 and PdSe2 – are discussed. The significance of this thesis can be broadly classified into the following three parts: 1. As one of the pioneer 2D materials to be in the TDMC family, MoS2 has proven itself to be a stellar material in electronic, optoelectronic and valleytronic applications. However, due to its large specific surface area, MoS2 is susceptible to absorbing oxygen species, which can have a tremendous influence on its properties. Previous works have mainly focussed on physisorbed oxygen, yet few studies have considered oxygen chemisorption on MoS2. To address this, a simple oxygen plasma process is used to introduce oxygen chemisorption on MoS2. Using Raman spectroscopy, the frequency of A1g mode is observed to be pinned while that of E12g mode redshifts. This is attributed to the softening of in-plane Mo-S force constants when oxygen atoms are chemisorbed onto the sulphur sites. Furthermore using photoluminescence spectroscopy, a redshift in the photoluminescence peak is observed and is attributed to the reduction of band gap in oxygen-chemisorbed MoS2. 2. In principle, any bulk crystals with interlayers bonded by van der Waals force can be thinned down to monolayer. This is the concept and motivation behind van der Waals heterostructures. Existing works have demonstrated the stacking of MoS2 with various materials such as graphene, hBN, WSe2, BP and CNTs, which are mostly inorganic based. To investigate further, an inorganic-organic heterostructure is presented, in which rubrene is used to stack with MoS2. Here, different applications are realised by changing the stacking configuration of the MoS2-rubrene heterostructure. First, a photodetector with fast photoresponse time (< 5 ms) coupled with high photoresponsivity (510 mA W-1 at 532 nm) is demonstrated. Second, an ambipolar FET with μe = 0.36 cm2V−1s−1 and μh = 1.27 cm2V−1s−1, coupled with an on/off ratio of 103 is achieved. Lastly, an inverter with good voltage gain of 2.3 has been realised. 3. Due to the rich chemistry of TMDCs, identifying promising new 2D materials will be instrumental towards creating next-generation 2D electronics. In this contribution, PdSe2, a promising TMDC, is introduced into the 2D family. The PdSe2 is grown by melting stoichiometric amount of Pd and Se powders where their crystal structure, phase, purity and composition are confirmed with XRD, EDS and TEM. Intrinsically, PdSe2 FETs are found to exhibit ambipolar carrier transport (μe (avg) = 17 cm2V−1s−1 and μh (avg) = 7 cm2V−1s−1, with on/off ratio of 102). Interestingly, high performance n-type PdSe2 FETs (μe = 216 cm2V−1s−1 with on/off ratio of 103) can be realised after vacuum annealing. Lastly, progressive p-doping in PdSe2 is also demonstrated using F4-TCNQ.Doctor of Philosophy (EEE

The usefulness of pocket PC in facilitating teaching in higher education

Mobile technologies offer new opportunities for electronic teaching and learning and including their ability to enable people to collaborate “anywhere, anytime”. They are, however, being introduced in an environment in which usage of electronic teaching and learning has increased apace without proper regard to its effectiveness and justification. Around the world tertiary institutions have invested heavily in technology with a view to their image in the eye of the public. In research and publication focused on higher education, little has examined the adoption and use of mobile handheld devices by academics or teachers. The aim of this paper is to examine how teaching academics perceive using a Pocket PC to facilitate university teaching and administrative duties. In this study the utility of Pocket PCs is compared with that of desktop and laptop computers operating in a wireless environment. A survey of academics using Pocket PCs was conducted and the results were analysed and interpreted. The results may assist the management of the tertiary institutions to enhance related services to both staff members and students

The Pocket PC as an information management tool for academics in Australia: an exploratory study

The increasing use of portable computers and mobile computing and telecommunication devices means a re-think of how we access and retrieve information. Like many workers in knowledge-rich professions, university academics in Australia are increasingly overloaded with information in the form of messages, notes, papers, publications, books and so on. They have to handle, process, store, and make decisions on the information received on a daily basis. Conversely, university academics are also expected, at times under pressure, to produce more of this type of information, which in turn, increases the pressure on their peers in academic circles to handle an increasing amount of information. The technological development that fosters the information explosion also produces new means of coping with it. This research investigated the potential of the Pocket PC to assist academics in meeting the increasing informational demands placed upon them

Ultralow-Power Alcohol Vapor Sensors Using Chemically Functionalized Multiwalled Carbon Nanotubes

Alcohol sensors, batch fabricated by forming bundles of chemically functionalized multiwalled carbon nanotubes (f-CNTs) across Au electrodes on SiO2/Si substrates using an AC electrophoretic technique, were developed for alcohol vapor detection using an ultralow input power of ∼ 0.01-1 μW, which is lower than the power required for most commercially available alcohol sensors by more than four orders of magnitude. The multiwalled carbon nanotubes (MWCNTs) have been chemically functionalized with the COOH groups by oxidation. We found that the sensors are selective with respect to flow from air, water vapor, and alcohol vapor. The sensor response is linear for alcohol vapor concentrations from 1 to 21 ppm with a detection limit of 0.9 ppm. The transient response of these sensors is experimentally shown to be ∼1 s and the variation of the responses at each concentration is within 10% for all of the tested sensors. The sensors could also easily be reset to their initial states by annealing the f-CNTs sensing elements at a current of 100-200 μA within ∼ 100-200 s. We demonstrated that the response of the sensors can be increased by one order of magnitude after adding the functional group COOH onto the nanotubes, i.e., from ∼0.9% of a bare MWCNTs sensor to ∼9.6% of an f-CNTs sensor with a dose of 21 ppm alcohol vapor. © 2007 IEEE

Band gap effects of hexagonal boron nitride using oxygen plasma

Tuning of band gap of hexagonal boron nitride (h-BN) has been a challenging problem due to its inherent chemical stability and inertness. In this work, we report the changes in band gaps in a few layers of chemical vapor deposition processed as-grown h-BN using a simple oxygen plasma treatment. Optical absorption spectra show a trend of band gap narrowing monotonically from 6 eV of pristine h-BN to 4.31 eV when exposed to oxygen plasma for 12 s. The narrowing of band gap causes the reduction in electrical resistance by ∼100 fold. The x-ray photoelectron spectroscopy results of plasma treated hexagonal boron nitride surface show the predominant doping of oxygen for the nitrogen vacancy. Energy sub-band formations inside the band gap of h-BN, due to the incorporation of oxygen dopants, cause a red shift in absorption edge corresponding to the band gap narrowing.Published versio