A fast and highly sensitive blood culture PCR method for clinical detection of Salmonella enterica serovar Typhi

<p>Abstract</p> <p>Background</p> <p><it>Salmonella </it>Typhi causes an estimated 21 million new cases of typhoid fever and 216,000 deaths every year. Blood culture is currently the gold standard for diagnosis of typhoid fever, but it is time-consuming and takes several days for isolation and identification of causative organisms. It is then too late to initiate proper antibiotic therapy. Serological tests have very low sensitivity and specificity, and no practical value in endemic areas. As early diagnosis of the disease and prompt treatment are essential for optimal management, especially in children, a rapid sensitive detection method for typhoid fever is urgently needed. Although PCR is sensitive and rapid, initial research indicated similar sensitivity to blood culture and lower specificity. We developed a fast and highly sensitive blood culture PCR method for detection of <it>Salmonella </it>Typhi, allowing same-day initiation of treatment after accurate diagnosis of typhoid.</p> <p>Methods</p> <p>An ox bile tryptone soy broth was optimized for blood culture, which allows the complete lysis of blood cells to release intracellular bacteria without inhibiting the growth of <it>Salmonella </it>Typhi. Using the optimised broth <it>Salmonella </it>Typhi bacteria in artificial blood samples were enriched in blood culture and then detected by a PCR targeting the <it>fliC-d </it>gene of <it>Salmonella </it>Typhi.</p> <p>Results</p> <p>Tests demonstrated that 2.4% ox bile in blood culture not only lyzes blood cells completely within 1.5 hours so that the intracellular bacteria could be released, but also has no inhibiting effect on the growth of <it>Salmonella </it>Typhi.</p> <p>Three hour enrichment of <it>Salmonella </it>Typhi in tryptone soya broth containing 2.4% ox bile could increase the bacterial number from 0.75 CFU per millilitre of blood which is similar to clinical typhoid samples to the level which regular PCR can detect. The whole blood culture PCR assay takes less than 8 hours to complete rather than several days for conventional blood culture.</p> <p>Conclusions</p> <p>This novel blood culture PCR method is superior in speed and sensitivity to both conventional blood culture and PCR assays. Its use in clinical diagnosis may allow early detection of the causative organism and facilitate initiation of prompt treatment among patients with typhoid fever.</p

Better by design: Business preferences for environmental regulatory reform

We present the preferences for environmental regulatory reform expressed by 30 UK businesses and industry bodies from 5 sectors. While five strongly preferred voluntary regulation, seven expressed doubts about its effectiveness, and 18 expressed no general preference between instrument types. Voluntary approaches were valued for flexibility and lower burdens, but direct regulation offered stability and a level playing field. Respondents sought regulatory frameworks that: are coherent; balance clarity, prescription and flexibility; are enabled by positive regulatory relationships; administratively efficient; targeted according to risk magnitude and character; evidence-based and that deliver long-term market stability for regulatees. Anticipated differences in performance between types of instrument can be undermined by poor implementation. Results underline the need for policy makers and regulators to tailor an effective mix of instruments for a given sector, and to overcome analytical, institutional and political barriers to greater coherence, to better coordinate existing instruments and tackle new environmental challenges as they emerge

Golf and upper limb injuries: a summary and review of the literature

BACKGROUND: Golf is a popular past time that provides exercise with social interaction. However, as with all sports and activities, injury may occur. Many golf-related injuries occur in the upper limb, yet little research on the potential mechanisms of these injuries has been conducted. OBJECTIVE: To review the current literature on golf-related upper limb injuries and report on potential causes of injury as it relates to the golf swing. DISCUSSION: An overview of the golf swing is described in terms of its potential to cause the frequently noted injuries. Most injuries occur at impact when the golf club hits the ball. This paper concludes that more research into golf-related upper limb injuries is required to develop a thorough understanding of how injuries occur. Types of research include epidemiology studies, kinematic swing analysis and electromyographic studies of the upper limb during golf. By conducting such research, preventative measures maybe developed to reduce golf related injury

Independent inventors and inbound open innovation: using a resource-based approach to create a tool for screening inventor approaches in order to facilitate technology in-licensing

Open innovation literature identifies independent inventors as a source of novel external knowledge. This knowledge may be licensed into an organisation in order to supplement internal R&D activity, typically as part of an inbound open innovation strategy. In opening an organisation up to approaches from individuals the capacity of the core team to identify promising licensing opportunities is diminished by the sheer volume and variable quality of approaches received. Based on a survey of 202 UK independent inventors this paper utilises a resource-based approach to identifying the key resources possessed by successful independent inventors. Using this data, we devise a preliminary screening tool to facilitate technology in-licensing from independent inventors

Space Launch System Aeroacoustic Wind Tunnel Test Results

Characterization of accurate launch vehicle unsteady aerodynamics is critical for component and secondary structure vibroacoustic design. For the National Aeronautics and Space Administration (NASA) Space Launch System (SLS), aeroacoustic environments have been derived primarily through sub-scale wind tunnel testing. Both optical techniques and high frequency pressure measurements have been utilized across multiple testing facilities and numerous vehicle configurations to develop a range of preliminary and detailed environments. As the vehicle has matured and evolved, the data collected from each subsequent configuration has allowed for comparison studies which isolate the effects of certain outer mold line (OML) features on measured fluctuating pressure levels. This paper presents observations on some of those effects for features which include abort system protuberances, various fairings geometries, interstage flanges, and multibody interactions between a central core and fall away boosters. These features, and the flow conditions produced by them, are broadly applicable to many launch vehicle configurations

Evaluation of the Induction of Immune Memory following Infant Immunisation with Serogroup C Neisseria meningitidis Conjugate Vaccines - Exploratory Analyses within a Randomised Controlled Trial

Aim: We measured meningococcal serogroup C (MenC)-specific memory B-cell responses in infants by Enzyme-Linked Immunospot (ELISpot) following different MenC conjugate vaccine schedules to investigate the impact of priming on immune memory. Methods: Infants aged 2 months were randomised to receive 1 or 2 doses of MenC-CRM197 at 3 or 3 and 4 months, 1 dose of MenC-TT at 3 months, or no primary MenC doses. All children received a Haemophilus influenzae type b (Hib)-MenC booster at 12 months. Blood was drawn at 5, 12, 12 months +6 days and 13 months of age. Results: Results were available for 110, 103, 76 and 44 children from each group respectively. Following primary immunisations, and prior to the 12-month booster, there were no significant differences between 1- or 2-dose primed children in the number of MenC memory B-cells detected. One month following the booster, children primed with 1 dose MenC-TT had more memory B-cells than children primed with either 1-dose (p = 0.001) or 2-dose (p<0.0001) MenC-CRM197. There were no differences in MenC memory B-cells detected in children who received 1 or 2 doses of MenC-CRM197 in infancy and un-primed children. Conclusions: MenC-specific memory B-cell production may be more dependent on the type of primary vaccine used than the number of doses administered. Although the mechanistic differences between MenC-CRM197 and MenC-TT priming are unclear, it is possible that structural differences, including the carrier proteins, may underlie differential interactions with B- and T-cell populations, and thus different effects on various memory B-cell subsets. A MenC-TT/Hib-MenC-TT combination for priming/boosting may offer an advantage in inducing more persistent antibody.peer-reviewe

Scanning probe microscopy of adsorbed molecules on boron nitride and graphene monolayers

In this thesis, a study of a range of functional surfaces formed in ultra-high vacuum (UHV) conditions using primarily scanning probe microscopy is presented. The construction of a combined scanning tunnelling and atomic force microscope, and the experiments performed using this instrument, are also detailed. Boron nitride and graphene monolayers were formed on rhodium thin films in UHV and investigated with in-situ and ex-situ (ambient conditions) scanning tunnelling microscopy. Simultaneous scanning tunnelling and atomic force microscopy images were also produced for the graphene monolayers. X-ray photoelectron spectroscopy and diffraction results for graphene monolayers on Rh(111) surfaces, as well as low energy electron diffraction data, are also included. The novel formation of monolayer and few-layer graphene on nickel thin films is also described. Graphene layers were detached from these nickel thin films and isolated on other substrates. The results of characterisation experiments using scanning probe microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy techniques are detailed. Graphene layers with approximately 75% monolayer graphene coverage and an increased electronic quality, when compared to many other methods of graphene production, were revealed. Different organic molecules were adsorbed on both the boron nitride and graphene monolayers formed on rhodium thin films in UHV conditions. Perylene tetracarboxylic diimide (PTCDI) and di(propylthio)-PTCDI molecules were investigated on these surfaces and compared with the adsorption of PTCDI on a graphite surface. Furthermore, dibutyl-coronene tetra-carboxylic diimide was deposited on the graphene (on rhodium) surface, in UHV. Although the boron nitride and graphene surfaces were similar, it was discovered that very contrasting molecular formations were formed on the dierent surfaces. The positioning of these nanostructures was determined by the Moire superstructure formed due to the mismatch between the monolayers and the Rh(111) surface. Additionally, different hydrogen-bonded molecular junctions were formed depending on the length of the side chains of the adsorbed organic molecules