Gastro-oesophageal reflux: An overview of the cost-effectiveness of pharmacotherapeutic treatment options

Gastro-oesophageal reflux disease (GORD) produces symptoms that cause great irritation to the patient. Pharmacotherapeutic management is directed at minimising these symptoms and reducing the causative factors, e.g. acid production, thereby providing relieve. Currently available agents include simple antacids and acid suppression therapy, including histamine 2-receptor antagonists, proton pump inhibitors, mucosal or cytoprotective agents, pro-motility agents. Deciding on appropriate therapy will be dependent on the diagnosis, side-effects and cost-effectiveness of the treatment.Keywords: GORD, gastro-oesophageal reflux, PPIs, proton-pump inhibitors, cost effectivenes

Publication trends of clinical trials performed in South Africa

Background. Investigators and sponsors of clinical trials have an ethical obligation to disseminate clinical trial results, whether positive or negative, in a timely manner.Objectives. To determine the publication rate and average time to reporting for clinical trials carried out in South Africa (SA) and to explore factors indicating whether a study is published or not.Methods. A registry-based quantitative retrospective analysis of 79 SA clinical trials for new medicines registered between January 2008 and December 2010 was performed. The relevant trial identification number in the register was used to track all peer-reviewed publications subsequent to registration. Tracking of clinical trials was done through a systematic literature search of the electronic journal databases of the South African Medical Journal (SAMJ), the Cochrane Library, Public Library of Science Medical Journal (PLoS Medicine) and BioMed Central, all of which are indexed on MEDLINE via PubMed. In addition, a manual search of the Open Access Journal of Clinical Trials databases and reference lists on articles related to the trial medicine was performed.Results. Of the 79 clinical trials surveyed, 72 were concluded by December 2014. Only 35 (48.6%) of them had the results published in a peer-reviewed journal, the current benchmark for dissemination of trial results. The majority (82.9%) of those published had a positive outcome. Of the 35 trials that were published, 77.1% were published within 2 years. The average time from completion to initial reporting was 22 months. Fewer than half (40.5%) of the clinical trials surveyed were placebo controlled.Conclusion. The absence of complete outcomes data from SA clinical trials warrants utmost attention. The study puts forward a case to the regulatory body and research ethics committees to compel all data from clinical trials to be made accessible to clinicians and the public in general by being published in an easily accessible form and in a timely manner

The Raman Fingerprint of Graphene

Graphene is the two-dimensional (2d) building block for carbon allotropes of every other dimensionality. It can be stacked into 3d graphite, rolled into 1d nanotubes, or wrapped into 0d fullerenes. Its recent discovery in free state has finally provided the possibility to study experimentally its electronic and phonon properties. Here we show that graphene's electronic structure is uniquely captured in its Raman spectrum that clearly evolves with increasing number of layers. Raman fingerprints for single-, bi- and few-layer graphene reflect changes in the electronic structure and electron-phonon interactions and allow unambiguous, high-throughput, non-destructive identification of graphene layers, which is critically lacking in this emerging research area

The Role of Deontic Logic in the Specification of Information Systems

In this paper we discuss the role that deontic logic plays in the specification of information systems, either because constraints on the systems directly concern norms or, and even more importantly, system constraints are considered ideal but violable (so-called `soft¿ constraints).\ud To overcome the traditional problems with deontic logic (the so-called paradoxes), we first state the importance of distinguishing between ought-to-be and ought-to-do constraints and next focus on the most severe paradox, the so-called Chisholm paradox, involving contrary-to-duty norms. We present a multi-modal extension of standard deontic logic (SDL) to represent the ought-to-be version of the Chisholm set properly. For the ought-to-do variant we employ a reduction to dynamic logic, and show how the Chisholm set can be treated adequately in this setting. Finally we discuss a way of integrating both ought-to-be and ought-to-do reasoning, enabling one to draw conclusions from ought-to-be constraints to ought-to-do ones, and show by an example the use(fulness) of this

Game saturation of intersecting families

We consider the following combinatorial game: two players, Fast and Slow, claim $k$-element subsets of $[n]=\{1,2,...,n\}$ alternately, one at each turn, such that both players are allowed to pick sets that intersect all previously claimed subsets. The game ends when there does not exist any unclaimed $k$-subset that meets all already claimed sets. The score of the game is the number of sets claimed by the two players, the aim of Fast is to keep the score as low as possible, while the aim of Slow is to postpone the game's end as long as possible. The game saturation number is the score of the game when both players play according to an optimal strategy. To be precise we have to distinguish two cases depending on which player takes the first move. Let $gsat_F(\mathbb{I}_{n,k})$ and $gsat_S(\mathbb{I}_{n,k})$ denote the score of the saturation game when both players play according to an optimal strategy and the game starts with Fast's or Slow's move, respectively. We prove that $\Omega_k(n^{k/3-5}) \le gsat_F(\mathbb{I}_{n,k}),gsat_S(\mathbb{I}_{n,k}) \le O_k(n^{k-\sqrt{k}/2})$ holds

Travel vaccines: Information for health care workers

Travel and volume of passengers and goods carried continue to expand in reach as more sophisticated air, sea and land transport networks develop. People are travelling for business and leisure, taking with them pathogens and their vectors bringing about diseases such as the global influenza pandemics. This review briefly examines some of the important vaccine preventable diseases related to travel. We then outline diseases known to Africa and other similar parts of the world, and potential approaches for  preventing these conditions. The paper provides practical advice for health care workers when consulting with the international traveler and hence may strengthen the battle against vaccine preventable diseases.Keywords: travel vaccines, yellow fever, dengue, polio, meningococcal meningiti

Development of a web-based application to improve data collection for antimicrobial point prevalence surveys in the public health care system in South Africa; findings and implications

Background: Surveillance of antimicrobial use is one of the main recommended strategies in combating growing antimicrobial resistance (AMR) rates and a key part of developing pertinent policies and initiatives to reduce growing AMR rates in South Africa and wider. However, determining antimicrobial utilisation at a patient-level among public hospitals in South Africa can be a challenge given personnel and resource constraints. There are also currently no standardized data collection tools. Most countries in Africa currently undertake antimicrobial utilisation surveillance using paper-based data collection tools including point prevalence surveys (PPS). Unfortunately, paper-based systems have disadvantages including the time taken to complete the forms and analyse the findings, increasing costs and manpower hurdles. Electronic tools offer many advantages including mobile and real time data collection and also the opportunity for rapid analytics. Objectives: Develop and test a web-based application (APP) for future PPS studies to successfully address identified challenges. Methods: A web based application (APP) was developed based on previous PPS in Botswana and South Africa using a paper-based data collection tool and tested during July 2017 in a leading public hospital in South Africa. The developed APP was also evaluated for data quality by measuring the number of errors, work flow, and time taken for the survey versus the previous paper-based system. User acceptance was also measured via a questionnaire to the data collectors. Results: A total of 187 patients' files were surveyed in this leading hospital using the APP whilst also documenting the challenges and areas of improvement for the APP. The identified areas of improvement have now been incorporated into the revised APP for future studies. The data collectors agreed that surveying the patients' files took appreciably less time with the APP compared to the paper based tool, and should be used in the future. In addition, data analysis was hastened using the APP. Conclusions: The APP development process has been successful and the APP is a potential tool for future PPS in South Africa and wider. The APP methodology is now being tested in new studies across South Africa to help instigate pertinent educational and other interventions to improve the future use of antimicrobials among public hospitals in South Africa

Towards atomically precise manipulation of 2D nanostructures in the electron microscope

Despite decades of research, the ultimate goal of nanotechnology—top-down manipulation of individual atoms—has been directly achieved with only one technique: scanning probe microscopy. In this review, we demonstrate that scanning transmission electron microscopy (STEM) is emerging as an alternative method for the direct assembly of nanostructures, with possible applications in plasmonics, quantum technologies, and materials science. Atomically precise manipulation with STEM relies on recent advances in instrumentation that have enabled non-destructive atomicresolution imaging at lower electron energies. While momentum transfer from highly energetic electrons often leads to atom ejection, interesting dynamics can be induced when the transferable kinetic energies are comparable to bond strengths in the material. Operating in this regime, very recent experiments have revealed the potential for single-atom manipulation using the Ångströmsized electron beam. To truly enable control, however, it is vital to understand the relevant atomicscale phenomena through accurate dynamical simulations. Although excellent agreement between experiment and theory for the specific case of atomic displacements from graphene has been recently achieved using density functional theory molecular dynamics, in many other cases quantitative accuracy remains a challenge. We provide a comprehensive reanalysis of available experimental data on beam-driven dynamics in light of the state-of-the-art in simulations, and identify important targets for improvement. Overall, the modern electron microscope has great potential to become an atom-scale fabrication platform, especially for covalently bonded 2D nanostructures. We review the developments that have made this possible, argue that graphene is an ideal starting material, and assess the main challenges moving forward

Correlation between nucleotide composition and folding energy of coding sequences with special attention to wobble bases

Background: The secondary structure and complexity of mRNA influences its accessibility to regulatory molecules (proteins, micro-RNAs), its stability and its level of expression. The mobile elements of the RNA sequence, the wobble bases, are expected to regulate the formation of structures encompassing coding sequences. Results: The sequence/folding energy (FE) relationship was studied by statistical, bioinformatic methods in 90 CDS containing 26,370 codons. I found that the FE (dG) associated with coding sequences is significant and negative (407 kcal/1000 bases, mean +/- S.E.M.) indicating that these sequences are able to form structures. However, the FE has only a small free component, less than 10% of the total. The contribution of the 1st and 3rd codon bases to the FE is larger than the contribution of the 2nd (central) bases. It is possible to achieve a ~ 4-fold change in FE by altering the wobble bases in synonymous codons. The sequence/FE relationship can be described with a simple algorithm, and the total FE can be predicted solely from the sequence composition of the nucleic acid. The contributions of different synonymous codons to the FE are additive and one codon cannot replace another. The accumulated contributions of synonymous codons of an amino acid to the total folding energy of an mRNA is strongly correlated to the relative amount of that amino acid in the translated protein. Conclusion: Synonymous codons are not interchangable with regard to their role in determining the mRNA FE and the relative amounts of amino acids in the translated protein, even if they are indistinguishable in respect of amino acid coding.Comment: 14 pages including 6 figures and 1 tabl