A prospective cohort study of the long-term effects of CPAP on carotid artery intima-media thickness in Obstructive sleep apnea syndrome

<p>Abstract</p> <p>Objective</p> <p>To examine the long-term effect of CPAP on carotid artery intima-media thickness (IMT) in patients with Obstructive sleep apnea syndrome(OSAS).</p> <p>Methods</p> <p>A prospective observational study over 12 months at a teaching hospital on 50 patients newly diagnosed with OSAS who received CPAP or conservative treatment (CT). Carotid IMT was assessed with B-mode Doppler ultrasound from both carotid arteries using images of the far wall of the distal 10 mm of the common carotid arteries at baseline, 6 months and 12 months.</p> <p>Measurements and results [mean (SE)]</p> <p>Altogether 28 and 22 patients received CPAP and CT respectively without significant differences in age 48.8(1.8) vs 50.5(2.0)yrs, BMI 28.2(0.7) vs 28.0(1.2)kg/m2, ESS 13.1(0.7) vs 12.7(0.6), AHI 38(3) vs 39(3)/hr, arousal index 29(2) vs 29(2)/hr, minimum SaO₂75(2) vs 77(2)% and existing co-morbidities. CPAP usage was 4.6(0.3) and 4.7(0.4)hrs/night over 6 months and 1 year respectively. Carotid artery IMT at baseline, 6 months, and 12 months were 758(30), 721(20), and 705(20)micron for the CPAP group versus 760(30), 770(30), and 778(30)micron respectively for the CT group, p = 0.002.</p> <p>Among those free of cardiovascular disease(n = 24), the carotid artery IMT at baseline, 6 months and 12 months were 722(40), 691(40), and 659(30)micron for the CPAP group (n = 12) with usage 4.5(0.7) and 4.7(0.7) hrs/night over 6 months and 12 months whereas the IMT data for the CT group(n = 12) were 660(20), 685(10), and 690(20)micron respectively, p = 0.006.</p> <p>Conclusions</p> <p>Reduction of carotid artery IMT occurred mostly in the first 6 months and was sustained at 12 months in patients with reasonable CPAP compliance.</p

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Computational flood modeling with UPC architecture

Demand for effective flood modeling and forecasting based on the two-dimensional shallow water equations has increased due to uncertainties with climate changes and the need for further accuracy in the urbanized environment. In this study, an alternative parallel computing architecture is presented that uses the Unified Parallel C (UPC) architecture, which combines the respective advantages of message passing interface (MPI) scalability with the direct memory access of OpenMP. A second-order Godunov-type monotone upstream scheme flood model, called ParaFlood2D, is developed using UPC as the first approach. The computational efficiency of ParaFlood2D is investigated with two cases of flood wave propagation on shared-memory and distributed-memory systems. In both cases, the simulation results demonstrate reasonably good accuracy when compared with the respective analytical solutions. At the same time, the obtained speed-up performance of UPC is generally more favorable when compared with that of MPI and OpenMP in their respective basic designs. Overall, the study indicates that UPC parallel architecture can be a viable alternative for large-scale flood modeling simulations.Nanyang Technological UniversityThis research study is funded by the internal core funding from the Nanyang Environment and Water Research Institute, Nanyang Technological University (NTU), Singapore. The first author is grateful to NTU’s Interdisciplinary Graduate School for the 4-year Ph.D. scholarship for his study. The fourth author is grateful to NTU for the 4-year Nanyang President Graduate Scholarship for his current Ph.D. study

Identification of polyketide inhibitors targeting 3-dehydroquinate dehydratase in the shikimate pathway of Enterococcus faecalis.

Due to the emergence of resistance toward current antibiotics, there is a pressing need to develop the next generation of antibiotics as therapeutics against infectious and opportunistic diseases of microbial origins. The shikimate pathway is exclusive to microbes, plants and fungi, and hence is an attractive and logical target for development of antimicrobial therapeutics. The Gram-positive commensal microbe, Enterococcus faecalis, is a major human pathogen associated with nosocomial infections and resistance to vancomycin, the "drug of last resort". Here, we report the identification of several polyketide-based inhibitors against the E. faecalis shikimate pathway enzyme, 3-dehydroquinate dehydratase (DHQase). In particular, marein, a flavonoid polyketide, both inhibited DHQase and retarded the growth of Enterococcus faecalis. The purification, crystallization and structural resolution of recombinant DHQase from E. faecalis (at 2.2 Å resolution) are also reported. This study provides a route in the development of polyketide-based antimicrobial inhibitors targeting the shikimate pathway of the human pathogen E. faecalis

List of flavonoids inhibiting <i>Enterococcus faecalis</i>.

<p>List of flavonoids inhibiting <i>Enterococcus faecalis</i>.</p

Data Collection, Refinement and Structure Validation Statistics.

<p>Data Collection, Refinement and Structure Validation Statistics.</p

Double-reciprocal plots for three of the identified inhibitors targeting efDHQase.

<p>Plot for aesculine (A) and marein (B) showing two possible scenarios for mixed inhibition where the lines intersect either below the x-axis or just after y-axis respectively. Plot for rutin (C) showing uncompetitive inhibition where the lines run parallel to one another.</p

efDHQase inhibition constants (<i>K</i>_I).

<p>efDHQase inhibition constants (<i>K</i>_I).</p