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41.
Lei Shang Niels Peter K. Nielsen Wolfgang Stelte Jonas Dahl Jesper Ahrenfeldt Jens Kai Holm Maria Puig Arnavat Lars S. Bach Ulrik B. Henriksen 《Bioenergy Research》2014,7(1):87-94
Combined torrefaction and pelletization is used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. In the present study, a single-pellet press tool was used to screen for the effects of pellet die temperature, moisture content, additive addition, and the degree of torrefaction on the pelletizing properties and pellet quality, i.e., density, static friction, and pellet strength. Results were compared with pellet production using a bench-scale pelletizer. The results indicate that friction is the key factor when scaling up from single-pellet press to bench-scale pelletizer. Tuning moisture content or increasing the die temperature did not ease the pellet production of torrefied wood chips significantly. The addition of rapeseed oil as a lubricant reduced the static friction by half and stabilized pellet production; however, the pellet quality, strength, and density were negatively affected. The pellets produced from pine wood torrefied at 250 and 280 °C were shorter than pellets produced from untreated wood and their quality did not match conventional wood pellet standards. However, the heating value of the torrefied pellets was higher and the particle size distribution after grinding the pellets was more uniform compared to conventional wood pellets. 相似文献
42.
Nakul Mandal Steffen Heegaard Jan Ulrik Prause Bent Honoré Henrik Vorum 《Biological procedures online》2010,12(1):56-88
The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of
ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass
spectrometry (MS). Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure
reliable results. Current methods of protein staining for 2D-PAGE, protein labelling for two-dimensional difference gel electrophoresis,
gel-based expression analysis and protein identification by MS are summarised. The uses of gel-free MS-based strategies (MuDPIT,
iTRAQ, ICAT and SILAC) are also discussed. Proteomic technologies promise to shed new light onto ocular disease processes
that could lead to the discovery of strong novel biomarkers and therapeutic targets useful in many ophthalmic conditions. 相似文献
43.
Peter Hammershøj Mikkel Jessing Anders Ø. Madsen Knud J. Jensen Jørn B. Christensen Ulrik Boas 《International journal of peptide research and therapeutics》2007,13(1-2):209-212
The development of new linkers (handles) for solid-phase synthesis provides new chemical opportunities for peptide synthesis.
To understand the chemical properties of a recently developed backbone amide linker from a structural perspective, the crystal
structure of S-((5-formyl-3,4-ethylenedioxy)thiophene-2-yl)-3-thiopropionic acid (T-BAL2) was studied. Specifically, we wished
to address whether this highly substituted thiophene retained planarity in the aromatic ring as well as between the aromatic
ring and the aldehyde carbonyl. Furthermore, we sought an explanation for the relatively low reactivity in reductive aminations
of the thienylaldehyde with amines in solution and on solid phase. Based on the crystal structure of T-BAL2, the thienyl-C
(aldehyde) and C–O (aldehyde) bond lengths were applied as measures for the electron-deficiency (electrophilicity) of the
aldehyde and compared to similar bond lengths found in previously reported formylated homo- and hetero-aromatic systems, which
show significantly higher reactivity towards imine formation. The bond lengths found in the present structure are in accordance
with normal C–C single bond and C–O double bond lengths. The high similarity in aldehyde bond lengths in the present system
and in the reported systems indicates similar electron distribution in these systems. The lower reactivity of the present
system may therefore not be attributed to electronic factors. 相似文献
44.
45.
Mie Agermose Gram Hanne-Dorthe Emborg Astrid Blicher Schelde Nikolaj Ulrik Friis Katrine Finderup Nielsen Ida Rask Moustsen-Helms Rebecca Legarth Janni Uyen Hoa Lam Manon Chaine Aisha Zahoor Malik Morten Rasmussen Jannik Fonager Raphael Niklaus Sieber Marc Stegger Steen Ethelberg Palle Valentiner-Branth Christian Holm Hansen 《PLoS medicine》2022,19(9)
BackgroundThe continued occurrence of more contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants and waning immunity over time require ongoing reevaluation of the vaccine effectiveness (VE). This study aimed to estimate the effectiveness in 2 age groups (12 to 59 and 60 years or above) of 2 or 3 vaccine doses (BNT162b2 mRNA or mRNA-1273) by time since vaccination against SARS-CoV-2 infection and Coronavirus Disease 2019 (COVID-19) hospitalization in an Alpha-, Delta-, or Omicron-dominated period.Methods and findingsA Danish nationwide cohort study design was used to estimate VE against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha, Delta, or Omicron variant. Information was obtained from nationwide registries and linked using a unique personal identification number. The study included all previously uninfected residents in Denmark aged 12 years or above (18 years or above for the analysis of 3 doses) in the Alpha (February 20 to June 15, 2021), Delta (July 4 to November 20, 2021), and Omicron (December 21, 2021 to January 31, 2022) dominated periods. VE estimates including 95% confidence intervals (CIs) were calculated (1-hazard ratio∙100) using Cox proportional hazard regression models with underlying calendar time and adjustments for age, sex, comorbidity, and geographical region. Vaccination status was included as a time-varying exposure. In the oldest age group, VE against infection after 2 doses was 90.7% (95% CI: 88.2; 92.7) for the Alpha variant, 82.3% (95% CI: 75.5; 87.2) for the Delta variant, and 39.9% (95% CI: 26.3; 50.9) for the Omicron variant 14 to 30 days since vaccination. The VE waned over time and was 73.2% (Alpha, 95% CI: 57.1; 83.3), 50.0% (Delta, 95% CI: 46.7; 53.0), and 4.4% (Omicron, 95% CI: −0.1; 8.7) >120 days since vaccination. Higher estimates were observed after the third dose with VE estimates against infection of 86.1% (Delta, 95% CI: 83.3; 88.4) and 57.7% (Omicron, 95% CI: 55.9; 59.5) 14 to 30 days since vaccination. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 98.1% or above for the Alpha and Delta variants. Among both age groups, VE against COVID-19 hospitalization 14 to 30 days since vaccination with 2 or 3 doses was 95.5% or above for the Omicron variant. The main limitation of this study is the nonrandomized study design including potential differences between the unvaccinated (reference group) and vaccinated individuals.ConclusionsTwo vaccine doses provided high protection against SARS-CoV-2 infection and COVID-19 hospitalization with the Alpha and Delta variants with protection, notably against infection, waning over time. Two vaccine doses provided only limited and short-lived protection against SARS-CoV-2 infection with Omicron. However, the protection against COVID-19 hospitalization following Omicron SARS-CoV-2 infection was higher. The third vaccine dose substantially increased the level and duration of protection against infection with the Omicron variant and provided a high level of sustained protection against COVID-19 hospitalization among the +60-year-olds.Mie Agermose Gram and colleagues estimate vaccine effectiveness against infection and COVID-19 hospitalization with the Alpha, Delta or Omicron variant in Denmark. 相似文献
46.
Vikram K Bhatia Kenneth L Madsen Andreas Kunding Per Hedegård Ulrik Gether Dimitrios Stamou 《The EMBO journal》2009,28(21):3303-3314
BAR (Bin/Amphiphysin/Rvs) domains and amphipathic α‐helices (AHs) are believed to be sensors of membrane curvature thus facilitating the assembly of protein complexes on curved membranes. Here, we used quantitative fluorescence microscopy to compare the binding of both motifs on single nanosized liposomes of different diameters and therefore membrane curvature. Characterization of members of the three BAR domain families showed surprisingly that the crescent‐shaped BAR dimer with its positively charged concave face is not able to sense membrane curvature. Mutagenesis on BAR domains showed that membrane curvature sensing critically depends on the N‐terminal AH and furthermore that BAR domains sense membrane curvature through hydrophobic insertion in lipid packing defects and not through electrostatics. Consequently, amphipathic motifs, such as AHs, that are often associated with BAR domains emerge as an important means for a protein to sense membrane curvature. Measurements on single liposomes allowed us to document heterogeneous binding behaviour within the ensemble and quantify the influence of liposome polydispersity on bulk membrane curvature sensing experiments. The latter results suggest that bulk liposome‐binding experiments should be interpreted with great caution. 相似文献
47.
Subjects typically choose to be presented with stimuli that predict the existence of future reinforcements. This so-called ‘observing behavior’ is evident in many species under various experimental conditions, including if the choice is expensive, or if there is nothing that subjects can do to improve their lot with the information gained. A recent study showed that the activities of putative midbrain dopamine neurons reflect this preference for observation in a way that appears to challenge the common prediction-error interpretation of these neurons. In this paper, we provide an alternative account according to which observing behavior arises from a small, possibly Pavlovian, bias associated with the operation of working memory. 相似文献
48.
49.
The effect of elimination treatment with benzyl benzoate was examined in 30 adults with asthma caused by sensitivity to house dust mites. The patients were randomised into a control and an active group, who treated their mattresses with benzyl benzoate (Acarosan®). The study lasted 12 months and the effect of the treatment was monitored by monthly dust sampling, analyzed for major allergens fromDermatophagoides pteronyssinus andfarinae by the ELISA method and for guanine by the Acarex® method. The clinical effect was assessed by measuring lung function, daily peak flows, symptoms and medicine consumption as well as skin prick tests, and specific IgE to mite allergens. For both groups, a significant decrease was observed in house dust mite allergens, but there was no significant difference between the groups. No considerable differences were observed in clinical parameters within or between the groups. A good correlation was observed between ELISA and Acarex®. but the latter showed a major variation in the different classes. In conclusion. treatment of mattresses with benzyl benzoate had no effect in a group of patients with asthma due to house dust mite allergy. Regular vacuum cleaning of the bed may reduce house dust mite allergen exposure. 相似文献
50.
Aerobic exercise training rescues cardiac protein quality control and blunts endoplasmic reticulum stress in heart failure rats
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Luiz H. M. Bozi Paulo R. Jannig Natale Rolim Vanessa A. Voltarelli Paulo M. M. Dourado Ulrik Wisløff Patricia C. Brum 《Journal of cellular and molecular medicine》2016,20(11):2208-2212
Cardiac endoplasmic reticulum (ER) stress through accumulation of misfolded proteins plays a pivotal role in cardiovascular diseases. In an attempt to reestablish ER homoeostasis, the unfolded protein response (UPR) is activated. However, if ER stress persists, sustained UPR activation leads to apoptosis. There is no available therapy for ER stress relief. Considering that aerobic exercise training (AET) attenuates oxidative stress, mitochondrial dysfunction and calcium imbalance, it may be a potential strategy to reestablish cardiac ER homoeostasis. We test the hypothesis that AET would attenuate impaired cardiac ER stress after myocardial infarction (MI). Wistar rats underwent to either MI or sham surgeries. Four weeks later, rats underwent to 8 weeks of moderate‐intensity AET. Myocardial infarction rats displayed cardiac dysfunction and lung oedema, suggesting heart failure. Cardiac dysfunction in MI rats was paralleled by increased protein levels of UPR markers (GRP78, DERLIN‐1 and CHOP), accumulation of misfolded and polyubiquitinated proteins, and reduced chymotrypsin‐like proteasome activity. These results suggest an impaired cardiac protein quality control. Aerobic exercise training improved exercise capacity and cardiac function of MI animals. Interestingly, AET blunted MI‐induced ER stress by reducing protein levels of UPR markers, and accumulation of both misfolded and polyubiquinated proteins, which was associated with restored proteasome activity. Taken together, our study provide evidence for AET attenuation of ER stress through the reestablishment of cardiac protein quality control, which contributes to better cardiac function in post‐MI heart failure rats. These results reinforce the importance of AET as primary non‐pharmacological therapy to cardiovascular disease. 相似文献