| 3381. |
- Margeridon-Thermet, Severine, et al.
(författare)
-
Low-Level Persistence of Drug Resistance Mutations in Hepatitis B Virus-Infected Subjects with a Past History of Lamivudine Treatment
- 2013
-
Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 57:1, s. 343-349
-
Tidskriftsartikel (refereegranskat)abstract
- We sought to determine the prevalence of hepatitis B virus (HBV) lamivudine (LAM)-resistant minority variants in subjects who once received LAM but had discontinued it prior to virus sampling. We performed direct PCR Sanger sequencing and ultradeep pyrosequencing (UDPS) of HBV reverse transcriptase (RT) of plasma viruses from 45 LAM-naive subjects and 46 LAM-experienced subjects who had discontinued LAM a median of 24 months earlier. UDPS was performed to a depth of similar to 3,000 reads per nucleotide. Minority variants were defined as differences from the Sanger sequence present in >= 0.5% of UDPS reads in a sample. Sanger sequencing identified >= 1 LAM resistance mutations (rtL80I/V, rtM204I, and rtA181T) in samples from 5 (11%) of 46 LAM-experienced and none of 45 LAM-naive subjects (0%; P = 0.06). UDPS detected >= 1 LAM resistance mutations (rtL80I/V, rtV173L, rtL180M, rtA181T, and rtM204I/V) in 10 (22%) of the 46 LAM-experienced subjects, including 5 in whom LAM resistance mutations were not identified by Sanger sequencing. Overall, LAM resistance mutations were more likely to be present in LAM-experienced (10/46, 22%) than LAM-naive subjects (0/45, 0%; P = 0.001). The median time since LAM discontinuation was 12.8 months in the 10 subjects with a LAM resistance mutation compared to 30.5 months in the 36 LAM-experienced subjects without a LAM resistance mutation (P < 0.001). The likelihood of detecting a LAM resistance mutation was significantly increased using UDPS compared to Sanger sequencing and was inversely associated with the time since LAM discontinuation.
|
|
| 3382. |
- Margeridon-Thermet, S, et al.
(författare)
-
Ultra-deep pyrosequencing of hepatitis B virus quasispecies from nucleoside and nucleotide reverse-transcriptase inhibitor (NRTI)-treated patients and NRTI-naive patients
- 2009
-
Ingår i: Journal of Infectious Diseases. - : University of Chicago Press. - 0022-1899 .- 1537-6613. ; 199:9, s. 1275-1285
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamics of emerging nucleoside and nucleotide reverse-transcriptase inhibitor (NRTI) resistance in hepatitis B virus (HBV) are not well understood because standard dideoxynucleotide direct polymerase chain reaction (PCR) sequencing assays detect drug-resistance mutations only after they have become dominant. To obtain insight into NRTI resistance, we used a new sequencing technology to characterize the spectrum of low-prevalence NRTI-resistance mutations in HBV obtained from 20 plasma samples from 11 NRTI-treated patients and 17 plasma samples from 17 NRTI-naive patients, by using standard direct PCR sequencing and ultra-deep pyrosequencing (UDPS). UDPS detected drug-resistance mutations that were not detected by PCR in 10 samples from 5 NRTI-treated patients, including the lamivudine-resistance mutation V173L (in 5 samples), the entecavir-resistance mutations T184S (in 2 samples) and S202G (in 1 sample), the adefovir-resistance mutation N236T (in 1 sample), and the lamivudine and adefovir-resistance mutations V173L, L180M, A181T, and M204V (in 1 sample). G-to-A hypermutation mediated by the apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like family of cytidine deaminases was estimated to be present in 0.6% of reverse-transcriptase genes. Genotype A coinfection was detected by UDPS in each of 3 patients in whom genotype G virus was detected by direct PCR sequencing. UDPS detected low-prevalence HBV variants with NRTI-resistance mutations, G-to-A hypermutation, and low-level dual genotype infection with a sensitivity not previously possible.
|
|
| 3383. |
- Markstedt, Kajsa, 1989, et al.
(författare)
-
Synthesis of tunable hydrogels based on O-acetyl-galactoglucomannans from spruce
- 2017
-
Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 157, s. 1349-1357
-
Tidskriftsartikel (refereegranskat)abstract
- © 2016 Elsevier LtdHydrogels with tunable mechanical properties based on O-acetyl-galactoglucomannans (GGMs) from spruce functionalized with tyramine, a molecule containing crosslinkable phenolic groups, were prepared. Gel formation was induced by enzymatic crosslinking at the addition of horse radish peroxidase and hydrogen peroxide to the modified GGMs. The degree of substitution determined the hydrogels final properties, and was varied by TEMPO oxidation of GGM to a degree of oxidation from 10 to 60%. GGM and its derivatives were characterized by gas chromatography and high pressure size exclusion chromatography to analyze sugar composition and molar mass, respectively. Tyramine-conjugated GGM was evaluated by nuclear magnetic resonance, fourier transform infrared spectroscopy and elemental analysis. Measurements of moduli over time showed crosslinking within 20 s and maximum stress of the prepared gels were compared by compression testing. Overall this system presents a cell friendly hydrogel from a renewable, low cost resource which could be applied in cell delivery, wound dressings, and biofabrication.
|
|
| 3384. |
- Marsh, Gary M., et al.
(författare)
-
Mortality Among Hardmetal Production Workers : Pooled Analysis of Cohort Data From an International Investigation
- 2017
-
Ingår i: Journal of Occupational and Environmental Medicine. - Philadelphia, PA, USA : Lippincott Williams & Wilkins. - 1076-2752 .- 1536-5948. ; 59:12, s. e342-e364
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Based on a pooled analysis of data from an international study, evaluate total and cause-specific mortality among hardmetal production workers with emphasis on lung cancer.METHODS: Study members were 32,354 workers from three companies and 17 manufacturing sites in five countries. We computed standardized mortality ratios and evaluated exposure-response via relative risk regression analysis.RESULTS: Among long-term workers, we observed overall deficits or slight excesses in deaths for total mortality, all cancers, and lung cancer and found no evidence of any exposure-response relationships for lung cancer.CONCLUSIONS: We found no evidence that duration, average intensity, or cumulative exposure to tungsten, cobalt, or nickel, at levels experienced by the workers examined, increases lung cancer mortality risks. We also found no evidence that work in these facilities increased mortality risks from any other causes of death.
|
|
| 3385. |
- Martin, Natalia, et al.
(författare)
-
Intrinsic Ligand Effect Governing the Catalytic Activity of Pd Oxide Thin Films
- 2014
-
Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 4:10, s. 3330-3334
-
Tidskriftsartikel (refereegranskat)abstract
- High-pressure X-ray photoelectron spectroscopy, mass spectrometry, and density functional theory calculations have been combined to study methane oxidation over Pd(100). The measurements reveal a high activity when a two-layer PdO(101) oriented film is formed. Although a one-layer PdO(101) film exhibits a similar surface structure, no or very little activity is observed. The calculations show that the presence of an oxygen atom directly below the coordinatively unsaturated Pd atom in the two-layer PdO(101) film is crucial for efficient methane dissociation, demonstrating a ligand effect that may be broadly important in determining the catalytic properties of oxide thin films.
|
|
| 3386. |
|
|
| 3387. |
- Massetti, Matteo, et al.
(författare)
-
Fully direct written organic micro-thermoelectric generators embedded in a plastic foil
- 2020
-
Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 75
-
Tidskriftsartikel (refereegranskat)abstract
- Organic materials have attracted great interest for thermoelectric applications due to their tuneable electronic properties, solution processability and earth-abundance, potentially enabling high-throughput realization of low-cost devices for low-power energy harvesting applications. So far, organic thermoelectricity has primarily focused on materials development, with less attention given to integrated generators. Yet, future applications will require the combination of efficient generators architectures and scalable manufacturing techniques to leverage the advantages of such promising materials. Here we report the realization of a monolithic organic micro-thermoelectric generator (mu-OTEG), using only direct writing methods, embedding the thermoelectric legs within a plastic substrate through a combination of direct laser writing and inkjet printing techniques. Employing PEDOT:PSS for the p-type legs and a doped fullerene derivative for the n-type ones, we demonstrate a mu-OTEG with power density of 30.5 nW/cm(2) under small thermal gradients, proving the concrete possibility of achieving power requirements of low-power, distributed sensing applications.
|
|
| 3388. |
|
|
| 3389. |
- McCloskey, E. V., et al.
(författare)
-
Fracture risk assessment by the FRAX model
- 2022
-
Ingår i: Climacteric. - : Informa UK Limited. - 1369-7137 .- 1473-0804. ; 25:1, s. 22-28
-
Tidskriftsartikel (refereegranskat)abstract
- The introduction of the FRAX algorithms has facilitated the assessment of fracture risk on the basis of fracture probability. FRAX integrates the influence of several well-validated risk factors for fracture with or without the use of bone mineral density. Since age-specific rates of fracture and death differ across the world, FRAX models are calibrated with regard to the epidemiology of hip fracture (preferably from national sources) and mortality (usually United Nations sources). Models are currently available for 73 nations or territories covering more than 80% of the world population. FRAX has been incorporated into more than 80 guidelines worldwide, although the nature of this application has been heterogeneous. The limitations of FRAX have been extensively reviewed. Arithmetic procedures have been proposed in order to address some of these limitations, which can be applied to conventional FRAX estimates to accommodate knowledge of dose exposure to glucocorticoids, concurrent data on lumbar spine bone mineral density, information on trabecular bone score, hip axis length, falls history, type 2 diabetes, immigration status and recency of prior fracture.
|
|
| 3390. |
- McCloskey, E. V., et al.
(författare)
-
Global impact of COVID-19 on non-communicable disease management: descriptive analysis of access to FRAX fracture risk online tool for prevention of osteoporotic fractures
- 2021
-
Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 32
-
Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic, and its management, is markedly impacting the management of osteoporosis as judged by access to online FRAX fracture risk assessments. Globally, access was 58% lower in April than in February 2020. Strategies to improve osteoporosis care, with greater use of fracture risk assessments, offer a partial solution. Introduction The COVID-19 pandemic is having a significant detrimental impact on the management of chronic diseases including osteoporosis. We have quantified the global impact by examining changes in the usage of online FRAX fracture risk assessments before and after the declaration of the pandemic (11 March 2020). Methods The study comprised a retrospective analysis using GoogleAnalytics data on daily sessions on the FRAX (R) website (www.sheffield.ac.uk/FRAX) from November 2019 to April 2020 (main analysis period February-April 2020), and the geographical source of that activity. Results Over February-April 2020, the FRAX website recorded 460,495 sessions from 184 countries, with 210,656 sessions in February alone. In March and April, the number of sessions fell by 23.1% and 58.3% respectively, a pattern not observed over the same period in 2019. There were smaller reductions in Asia than elsewhere, partly related to earlier and less-marked nadirs in some countries (China, Taiwan, Hong Kong, South Korea and Vietnam). In Europe, the majority of countries (24/31, 77.4%) reduced usage by at least 50% in April. Seven countries showed smaller reductions (range - 2.85 to - 44.1%) including Poland, Slovakia, Czech Republic, Germany, Norway, Sweden and Finland. There was no significant relationship between the reduction in FRAX usage and measures of disease burden such as COVID-attributed deaths per million of the population. Conclusion This study documents a marked global impact of the COVID-19 pandemic on the management of osteoporosis as reflected by FRAX online fracture risk assessments. The analysis suggests that impact may relate to the societal and healthcare measures taken to ameliorate the pandemic.
|
|
