2,210 research outputs found
Understanding the interactions of cellulose fibres and deep eutectic solvent of choline chloride and urea
This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.A deep eutectic solvent composed of choline chloride (ChCl) and urea has been recently introduced as a promising cellulose compatible medium that enables e.g. fibre spinning. This paper clarifies the influence of such a solvent system on the structure and chemical composition of the cellulosic pulp fibres. Special emphasis was placed on the probable alterations of the chemical composition due to the dissolution of the fibre components and/or due to the chemical derivatisation taking place during the DES treatment. Possible changes in fibre morphology were studied with atomic force microscopy and scanning electron microscopy. Chemical compositions of pulp fibres were determined from the carbohydrate content, and by analysing the elemental content. Detailed structural characterisation of the fibres was carried out using spectroscopic methods; namely X-Ray Photoelectron Spectroscopy, solid state Nuclear Magnetic Resonance and Raman Spectroscopy. No changes with respect to fibre morphology were revealed and negligible changes in the carbohydrate composition were noted. The most significant change was related to the nitrogen content of the pulp after the DES treatment. Comprehensive examination using spectroscopic methods revealed that the nitrogen originated from strongly bound ChCl residuals that could not be removed with a mild ethanol washing procedure. According to Raman spectroscopic data and methylene blue adsorption tests, the cationic groups of ChCl seems to be attached to the anionic groups of pulp by electrostatic forces. These findings will facilitate the efficient utilisation of DES as a cellulose compatible medium without significantly affecting the native fibre structure.The authors acknowledge the Finnish Funding Agency for Innovation (TEKES) for funding the work via Design Driven Value Chains in the World of Cellulose 2.0 project. The Academy of Finland (Project ID 300367) is acknowledged for enabling the research mobility of T.T. to the University of Exeter, UK. Unto Tapper (VTT) is thanked for the SEM imaging, Atte Mikkelson, Ritva Heinonen and Marita Ikonen (VTT) for the chemical analysis and Robertus Nugroho (Aalto University) for the AFM imaging
Clinical Observation Study of Massive Blood Transfusion in a Tertiary Care Hospital in Korea
PURPOSE: Massive blood transfusios are uncommon. The goal of this study was to propose an ideal ratio for the blood component of massive hemorrhage treatment after review of five years of massive transfusion practice, in order to have the best possible clinical outcomes.
MATERIALS AND METHODS: We defined a 'massive transfusion' as receiving 10 or more units of red blood cells in one day. A list of patients receiving a massive transfusion from 2004 to 2008 was generated using the electronic medical records. For each case, we calculated the ratio of blood components and examined its relationship to their survival.
RESULTS: Three hundred thirty four patients underwent massive transfusion during the five years of the study. The overall seven-day hospital mortality for massive transfusion patients was 26.1%. Factors independently predictive of survival were a fresh-frozen plasma (FFP)/packed red blood cell (pRBC) ratio ≥ 1.1 with an odds ratio (OR) of 1.96 (1.03-3.70), and elective admission with an OR of 2.6 (1.52-4.40). The receiver operation characteristic (ROC) curve suggest that a 1 : 1 : 1 ratio of pRBCs to FFP to platelets is the best ratio for survival.
CONCLUSION: Fixing blood-component ratios during active hemorrhage shows improved outcomes. Thus, the hospital blood bank and physician hypothesized that a fixed blood component ratio would help to reduce mortality and decrease utilization of the overall blood componentope
Keep looking ahead? Re-direction of visual fixation does not always occur during an unpredictable obstacle avoidance task
Visual information about the environment, especially fixation of key objects such as obstacles, is critical for safe locomotion. However, in unpredictable situations where an obstacle suddenly appears it is not known whether central vision of the obstacle and/or landing area is required or if peripheral vision is sufficient. We examined whether there is a re-direction of visual fixation from an object fixated ahead to a suddenly appearing obstacle during treadmill walking. Furthermore, we investigated the temporal relationship between the onset of muscle activity to avoid the obstacle and saccadic eye and head movements to shift fixation. Eight females (mean SD; age = 24.8 2.3 years) participated in this experiment. There were two visual conditions: a central vision condition where participants fixated on two obstacles attached to a bridge on the treadmill and a peripheral vision condition where participants fixated an object two steps ahead. There were two obstacle release conditions: only an obstacle in front of the left foot was released or an obstacle in front of either foot could be released. Only trials when the obstacle was released in front of the left foot were analyzed such that the difference in the two obstacle conditions was whether there was a choice of which foot to step over the obstacle. Obstacles were released randomly in one of three phases during the step cycle corresponding to available response times between 219 and 462 ms. We monitored eye and head movements along with muscle activity and spatial foot parameters. Performance on the task was not different between vision conditions. The results indicated that saccades are rarely made (< 18% of trials) and, when present, are initiated ∼ 350 ms after muscle activity for limb elevation, often accompanied by a downward head movement, and always directed to the landing area. Therefore, peripheral vision of a suddenly appearing obstacle in the travel path is sufficient for successful obstacle avoidance during locomotion: visual fixation is generally not re-directed to either the obstacle or landing area
DNA methylation outlier burden, health and ageing in Generation Scotland and the Lothian Birth Cohorts of 1921 and 1936
Clinical trials update of the European Organization for Research and Treatment of Cancer Breast Cancer Group
The present clinical trial update consists of a review of two of eight current studies (the 10981-22023 AMAROS trial and the 10994 p53 trial) of the European Organization for Research and Treatment of Cancer Breast Cancer Group, as well as a preview of the MIND-ACT trial. The AMAROS trial is designed to prove equivalent local/regional control for patients with proven axillary lymph node metastasis by sentinel node biopsy if treated with axillary radiotherapy instead of axillary lymph node dissection, with reduced morbidity. The p53 trial started to assess the potential predictive value of p53 using a functional assay in yeast in patients with locally advanced/inflammatory or large operable breast cancer prospectively randomised to a taxane regimen versus a nontaxane regimen
Justification of the symmetric damping model of the dynamical Casimir effect in a cavity with a semiconductor mirror
A "microscopic" justification of the "symmetric damping" model of a quantum
oscillator with time-dependent frequency and time-dependent damping is given.
This model is used to predict results of experiments on simulating the
dynamical Casimir effect in a cavity with a photo-excited semiconductor mirror.
It is shown that the most general bilinear time-dependent coupling of a
selected oscillator (field mode) to a bath of harmonic oscillators results in
two equal friction coefficients for the both quadratures, provided all the
coupling coefficients are proportional to a single arbitrary function of time
whose duration is much shorter than the periods of all oscillators. The choice
of coupling in the rotating wave approximation form leads to the "mimimum
noise" model of the quantum damped oscillator, introduced earlier in a pure
phenomenological way.Comment: 9 pages, typos corrected, corresponds to the published version,
except for the reference styl
Carotid bruits as predictor for carotid stenoses detected by ultrasonography: an observational study
<p>Abstract</p> <p>Background</p> <p>Carotid surgery in asymptomatic subjects with carotid stenosis is effective to prevent ischemic stroke. There is, however, uncertainty how to find such persons at risk, because mass screening with carotid artery ultrasonography (US) is not cost-effective. Signs of carotid bruits corresponding to the carotid arteries may serve as a tool to select subjects for further investigation. This study is thus aimed at determining the usefulness of carotid bruits in the screening of carotid stenoses.</p> <p>Methods</p> <p>1555 consecutive carotid ultrasonography investigations from 1486 cases done between January 2004 and March 2006 at Norrlands University Hospital, Sweden, were examined. 356 subjects, medium age 69 (27–88) years, had a significant (≥ 50%) US-verified carotid stenosis uni- or bilaterally, 291 had been examined for signs of carotid bruits. The likelihood ratios for carotid bruits to predict US-verified carotid stenoses were calculated and expressed as likelihood percentages.</p> <p>Results</p> <p>Thirty-one out of 100 persons (31%) with carotid bruit as an indication to perform carotid US had a significant (≥ 50%) carotid stenosis. 281 of the 356 (79%) cases with significant carotid stenoses were found among patients with cerebrovascular disease (CVD). 145 of 226 (64%) CVD patients with a significant carotid stenosis had a carotid bruit. In patients with 50–99% carotid stenoses carotid bruits had an accuracy of 75% (436/582), a sensitivity of 71% (236/334), a specificity of 81% (200/248), a positive likelihood ratio at 3.65 and a negative likelihood at 0.36. Patients with 70–99% stenoses had the highest sensitivity at 77% (183/238). In patients with 100% carotid stenoses, carotid bruits had a sensitivity of 26% (15/57) and a specificity of 49% (256/525).</p> <p>Conclusion</p> <p>Although carotid bruits are not accurate to confirm or to exclude significant carotid stenoses, these signs are appropriate for directed screening for further investigation with carotid US if the patient lacks contraindications for surgery. Lack of carotid bruits in CVD patients does not exclude a carotid stenosis.</p
Surrogate consent to non-beneficial research: erring on the right side when substituted judgments may be inaccurate
An effective all-atom potential for proteins
We describe and test an implicit solvent all-atom potential for simulations
of protein folding and aggregation. The potential is developed through studies
of structural and thermodynamic properties of 17 peptides with diverse
secondary structure. Results obtained using the final form of the potential are
presented for all these peptides. The same model, with unchanged parameters, is
furthermore applied to a heterodimeric coiled-coil system, a mixed alpha/beta
protein and a three-helix-bundle protein, with very good results. The
computational efficiency of the potential makes it possible to investigate the
free-energy landscape of these 49--67-residue systems with high statistical
accuracy, using only modest computational resources by today's standards
Dietary differences between elderly Iranians living in Sweden and Iran a cross-sectional comparative study
<p>Abstract</p> <p>Background</p> <p>During the last decades, global migration has increased and many immigrant groups have a higher prevalence than the native born population of several cardiovascular disease risk factors, including poor dietary habits. However, it is uncertain if dietary habits in immigrant populations reflect dietary habits in their country of origin or if the current diet is a consequence of the migration and possible change of dietary habits. The aim of this study was to examine possible dietary differences between elderly Iranians living in Stockholm, Sweden with elderly Iranians living in Tehran, Iran, taking into account sex, age, marital status, and education.</p> <p>Methods</p> <p>Dietary intakes were assessed by semi - quantitative food frequency questionnaire in a cross-sectional study of 121 Iranians living in Stockholm and 52 Iranians living in Tehran, aged 60-80. Differences in dietary habits between the two groups was analysed by bootstrapped regression analyses with 1000 replications.</p> <p>Results</p> <p>Iranians living in Sweden had significantly higher intake of protein, total fat, fiber than Iranians living in Iran, but lower consumption of carbohydrates. The observed differences in intake of macronutrients were reflected in consumed amount of all food items, which were higher among Iranians living in Iran with the exception of bread and grain consumption which was lower.</p> <p>Conclusions</p> <p>There are general differences in dietary habits between Iranians living in Iran and Iranians living in Sweden. Parts of observed differences in dietary habits may reflect a favourable adoption process to the Swedish dietary habits after migration. Meanwhile other differences are point of concern in light of the high prevalence of overweight, among Iranians living in Sweden and can have unfavourable impact in particular in the context of cardiovascular health.</p
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