235 research outputs found
Linear Contraction Behavior of Low-Carbon, Low-Alloy Steels During and After Solidification Using Real-Time Measurements
A technique for measuring the linear contraction during and after solidification of low-alloy steel was developed and used for examination of two commercial low-carbon and low-alloy steel grades. The effects of several experimental parameters on the contraction were studied. The solidification contraction behavior was described using the concept of rigidity in a solidifying alloy, evolution of the solid fraction, and the microstructure development during solidification. A correlation between the linear contraction properties in the solidification range and the hot crack susceptibility was proposed and used for the estimation of hot cracking susceptibility for two studied alloys and verified with the real casting practice. The technique allows estimation of the contraction coefficient of commercial steels in a wide range of temperatures and could be helpful for computer simulation and process optimization during continuous casting. © 2013 The Minerals, Metals & Materials Society and ASM International
Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases.
Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article
Randomized multicenter study on the plaque removal efficacy of 2 interdental brushes around the base of orthodontic brackets.
INTRODUCTION
The objective of this multicenter study was to analyze the efficacy of cleaning 2 interdental brushes (IDBs) around brackets in patients with fixed orthodontic appliances.
METHODS
The study design was a multicenter, randomized, examiner-blinded crossover study with 3 interventions, the first of which was a baseline intervention. This study included 20 patients (12 females, 8 males) aged 12-18 years with fixed orthodontic devices examined at the Department of Orthodontics, University Medical Center of the Johannes Gutenberg University Mainz, and the Children's Dental Clinic St. Gallen. The outcome was a conventional, cylindrically shaped IDB (IDBG-S [IB]; Top Caredent GmbH, Schönau, Germany) was examined in comparison with an innovative waist-shaped IDB (Circum, CDB-8 [CB]; Top Caredent GmbH). The participants did not use the IDB themselves. The brushing procedure was performed professionally by 1 operator (C.E.). Each buccal tooth surface with a bracket was split into 8 areas, the main areas being 1 and 8. These main areas, which were difficult for toothbrushes to reach, were mesial (area 1) and distal (area 8) of the bracket edges in the gingival direction. Plaque index (PI) scores were assessed at 2 examinations before and after the cleaning procedure on 8 tooth surfaces in the area with orthodontic brackets. A computer-generated program randomly allocated the IDB sequence to the participants. Examiners (L.Z.-G. and Y.W.) assessing the outcomes were blinded to the intervention and the randomized allocation of participants to the different IDBs.
RESULTS
Both IDBs showed a plaque removal effect (CB, 0.68 [interquartile range, 0.63-0.77]; IB, 0.43 [interquartile range, 0.33-0.55]). The difference between the 2 IDB was statistically significant (P = 0.002). In particular, the CB yielded a higher plaque removal efficacy (CB effect, 0.68; IB effect, 0.21) at the main areas 1 and 8, which were difficult to reach. Ten participants were randomized to each sequence, and all 20 completed the study. No side effects or adverse events were reported or observed.
CONCLUSION
The waist-shaped brush head of the CB significantly enhanced plaque reduction in total and particularly in problem areas.
REGISTRATION
This trial was registered at the German Clinical Trials Registry (no. DRKS00014088; https://www.drks.de/drks_web/navigate.xxdo?navigationId=trial.HTML&TRIAL_ID=DRKS00014088) PROTOCOL: The protocol was not published before trial commencement.
FUNDING
This study was supported by the manufacturer Top Caredent GmbH, Schönau, Germany, which provided all interdental brushes used in this study
Proton Transfer, Hydrogen Bonding, and Disorder: Nitrogen Near-Edge X-ray Absorption Fine Structure and X-ray Photoelectron Spectroscopy of Bipyridine-Acid Salts and Co-crystals
The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to Brønsted donation and the protonation state of nitrogen in the solid state is investigated through a series of multicomponent bipyridine–acid systems alongside X-ray photoelectron spectroscopy (XPS) data. A large shift to high energy occurs for the 1s → 1π* resonance in the nitrogen K-edge NEXAFS with proton transfer from the acid to the bipyridine base molecule and allows assignment as a salt (C═NH+), with the peak ratio providing the stoichiometry of the types of nitrogen species present. A corresponding binding energy shift for C═NH+ is observed in the nitrogen XPS, clearly identifying protonation and formation of a salt. The similar magnitude shifts observed with both techniques relative to the unprotonated nitrogen of co-crystals (C═N) suggest that the chemical state (initial-state) effects dominate. Results from both techniques reveal the sensitivity to identify proton transfer, hydrogen bond disorder, and even the potential to distinguish variations in hydrogen bond length to nitrogen
In-hospital outcomes of catheter-directed thrombolysis in patients with pulmonary embolism
AIMS
Catheter-directed treatment of acute pulmonary embolism (PE) is technically advancing. Recent guidelines acknowledge this treatment option for patients with overt or imminent haemodynamic decompensation, particularly when systemic thrombolysis is contraindicated. We investigated patients with PE who underwent catheter-directed thrombolysis (CDT) in the German nationwide inpatient cohort.
METHODS AND RESULTS
Data from hospitalizations with PE (International Classification of Disease code I26) between 2005 and 2016 were collected by the Federal Office of Statistics in Germany. Patients with PE who underwent CDT (OPS 8-838.60 or OPS code 8-83b.j) were compared with patients receiving systemic thrombolysis (OPS code 8-020.8), and those without thrombolytic or other reperfusion treatment. The analysis was not prespecified; therefore, our findings can only be considered to be hypothesis generating. We analysed data from 978 094 hospitalized patients with PE. Of these, 41 903 (4.3%) patients received thrombolytic treatment [systemic thrombolysis in 4.2%, CDT in 0.1% (1175 patients)]. Among patients with shock, CDT was associated with lower in-hospital mortality compared to systemic thrombolysis [odds ratios (OR) 0.30 (95% 0.14-0.67); P = 0.003]. Intracranial bleeding occurred in 14 (1.2%) patients who received CDT. Among haemodynamically stable patients with right ventricular dysfunction (intermediate-risk PE), CDT also was associated with a lower risk of in-hospital mortality compared to systemic thrombolysis {OR 0.55 [95% confidence interval (CI) 0.40-0.75]; P < 0.001} or no thrombolytic treatment [0.45 (95% CI 0.33-0.62); P < 0.001].
CONCLUSION
In the German nationwide inpatient cohort, based on administrative data, CDT was associated with lower in-hospital mortality rates compared to systemic thrombolysis, but the overall rate of intracranial bleeding in patients who received CDT was not negligible. Prospective controlled data are urgently needed to determine the true value of this treatment option in acute PE
Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases
Central corneal thickness (CCT) is a highly heritable trait associated with complex eye diseases such as keratoconus and glaucoma. We perform a genome-wide association meta-analysis of CCT and identify 19 novel regions. In addition to adding support for known connective tissue-related pathways, pathway analyses uncover previously unreported gene sets. Remarkably, >20% of the CCT-loci are near or within Mendelian disorder genes. These included FBN1, ADAMTS2 and TGFB2 which associate with connective tissue disorders (Marfan, Ehlers-Danlos and Loeys-Dietz syndromes), and the LUM-DCN-KERA gene complex involved in myopia, corneal dystrophies and cornea plana. Using index CCT-increasing variants, we find a significant inverse correlation in effect sizes between CCT and keratoconus (r =-0.62, P = 5.30 × 10-5) but not between CCT and primary open-angle glaucoma (r =-0.17, P = 0.2). Our findings provide evidence for shared genetic influences between CCT and keratoconus, and implicate candidate genes acting in collagen and extracellular matrix regulation
Probing hydrogen positions in hydrous compounds:information from parametric neutron powder diffraction studies
We demonstrate the extent to which modern detector technology, coupled with a high flux constant wavelength neutron source, can be used to obtain high quality diffraction data from short data collections, allowing the refinement of the full structures (including hydrogen positions) of hydrous compounds from in situ neutron powder diffraction measurements. The in situ thermodiffractometry and controlled humidity studies reported here reveal that important information on the reorientations of structural water molecules with changing conditions can be easily extracted, providing insight into the effects of hydrogen bonding on bulk physical properties. Using crystalline BaCl2 center dot 2H(2)O as an example system, we analyse the structural changes in the compound and its dehydration intermediates with changing temperature and humidity levels to demonstrate the quality of the dynamic structural information on the hydrogen atoms and associated hydrogen bonding that can be obtained without resorting to sample deuteration
Determining hydrogen positions in crystal engineered organic molecular complexes by joint neutron powder and single crystal X-ray diffraction
Ultrasound-facilitated, catheter-directed thrombolysis vs anticoagulation alone for acute intermediate-high-risk pulmonary embolism: Rationale and design of the HI-PEITHO study
BACKGROUND: Due to the bleeding risk of full-dose systemic thrombolysis and the lack of major trials focusing on the clinical benefits of catheter-directed treatment, heparin antiocoagulation remains the standard of care for patients with intermediate-high-risk pulmonary embolism (PE).
METHODS AND RESULTS: The Higher-Risk Pulmonary Embolism Thrombolysis (HI-PEITHO) study (ClinicalTrials.gov Identifier: NCT04790370) is a multinational multicenter randomized controlled parallel-group comparison trial. Patients with: (1) confirmed acute PE; (2) evidence of right ventricular (RV) dysfunction on imaging; (3) a positive cardiac troponin test; and (4) clinical criteria indicating an elevated risk of early death or imminent hemodynamic collapse, will be randomized 1:1 to treatment with a standardized protocol of ultrasound-facilitated catheter-directed thrombolysis plus anticoagulation, vs anticoagulation alone. The primary outcome is a composite of PE-related mortality, cardiorespiratory decompensation or collapse, or non-fatal symptomatic and objectively confirmed PE recurrence, within 7 days of randomization. Further assessments cover, apart from bleeding complications, a broad spectrum of functional and patient-reported outcomes including quality of life indicators, functional status and the utilization of health care resources over a 12-month follow-up period. The trial plans to include 406 patients, but the adaptive design permits a sample size increase depending on the results of the predefined interim analysis. As of May 11, 2022, 27 subjects have been enrolled. The trial is funded by Boston Scientific Corporation and through collaborative research agreements with University of Mainz and The PERT Consortium.
CONCLUSIONS: Regardless of the outcome, HI-PEITHO will establish the first-line treatment in intermediate-high risk PE patients with imminent hemodynamic collapse. The trial is expected to inform international guidelines and set the standard for evaluation of catheter-directed reperfusion options in the future
The kinetics of bulk hydration of the disaccharides α-lactose and trehalose by <i>in situ</i> neutron powder diffraction
The hydrations of the excipients stable α-lactose (Lαs), with two particle sizes, and trehalose have been studied by neutron powder diffraction; analysis of the Avrami plots, derived from the bulk polycrystalline phase compositions, allows elucidation of the kinetics and mechanisms involved in these hydration processes
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