778 research outputs found
How other Europeans assess the dangers of leaving the EU
Public support for the EU rose after the referendum, while Jean-Claude Juncker has painted a starry picture of the Union's prospects without Britain. In effect, writes Catherine E De Vries, the UK is a guinea pig for Eurosceptics on the rest of the continent. Consequently, national leaders have every incentive to make Brexit as arduous as possible for the UK. Parties like the AfD are watching
Synthesis of Chromones via Palladium-Catalyzed Ligand-Free Cyclocarbonylation of <i>o</i>-Iodophenols with Terminal Acetylenes in Phosphonium Salt Ionic Liquids
The highly efficient and selective palladium-catalyzed ligand-free cyclocarbonylation reaction of o-iodophenols with terminal acetylenes and CO in the phosphonium salt ionic liquid, C14H29(C6H13)3P+Br−, affords diversified chromones in good to excellent yields under atmospheric CO pressure. The ionic liquid, as the reaction medium, enhances the efficiency of the cyclocarbonylation reaction
Novel Membrane Adsorbers with Grafted Zwitterionic Polymers Synthesized by Surface-Initiated ATRP and Their Salt-Modulated Permeability and Protein Binding Properties
A novel zwitterionic polymer functionalized porous membrane
adsorber
was obtained by grafting poly(N,N-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl)
ammonium betaine) (polySPE) to poly(ethylene terephthalate) (PET)
track-etched membrane surface via surface-initiated atom transfer
radical polymerization (SI-ATRP). The ATRP conditions were optimized,
the thus established grafting was well-controlled, and the degree
of grafting could be adjusted. Functionalized membranes with a degree
of grafting of about 3.5 μg/cm<sup>2</sup> relative to the specific
surface area showed almost zero values of zeta potential estimated
from the trans-membrane streaming potential measurements. Typical
“anti-polyelectrolyte” effect was observed for the polySPE
grafted membranes. Flux through the membrane was reduced by adding
chaotropic chloride and perchlorate salts to the solution which extended
the polySPE chains grafted on the membrane pore wall. Perchlorate
salt exhibited much stronger effect on polySPE chain conformation
than chloride salt and for a membrane with a degree of grafting of
2.7 μg/cm<sup>2</sup>, even 2 mM KClO<sub>4</sub> could extend
the thickness of the polymer layer to more than two times (∼43
nm) of that in pure water (∼20 nm). On the contrary, small
amounts of kosmotropic ions (10 mM SO<sub>4</sub><sup>2‑</sup>) further “salted out” the polySPE chains and led to
a slightly increased flux. PolySPE grafted PET membranes with different
degree of grafting were then used as membrane adsorber for protein
binding. Human IgG was used as model protein and the binding capacity
was evaluated under both static (no convective flow through the membrane)
and dynamic conditions (flow-through conditions). Static adsorption
experiments showed that IgG could be loaded to the membrane at medium
salt concentration and 85–95% of bound protein could be eluted
at either low (zero) or very high salt concentrations. Dynamic flow-through
experiments then revealed the influences of salt concentration and
salt type on IgG binding. Effects of two chaotropic salts, NaCl and
NaClO<sub>4</sub>, were evaluated. Slight but not negligible binding
of IgG from pure water was suppressed by adding NaCl. IgG binding
was then increased in the NaCl concentration range of 100–500
mM and reached a maximum binding capacity value at about 500 mM. Further
increase of NaCl concentration led to a decreased binding again. KClO<sub>4</sub> showed similar effects onto IgG binding, but this salt functions
in a much lower and much narrower concentration range. All results
with respect to grafted layer swelling and protein binding followed
the empirical Hofmeister series
The Effects of Saline Water Drip Irrigation on Tomato Yield, Quality, and Blossom-End Rot Incidence --- A 3a Case Study in the South of China
<div><p>Saline water resources are abundant in the coastal areas of south China. Most of these resources still have not been effectively utilized. A 3-year study on the effects of saline water irrigation on tomato yield, quality and blossom-end rot (BER) was conducted at different lower limits of soil matric potential (-10 kPa, -20 kPa, -30 kPa, -40 kPa and -50 kPa). Saline water differing in electrical conductivity (EC) (3 dS/m, 4 dS/m, 4.5 dS/m, 5 dS/m and 5.5 dS/m) was supplied to the plant after the seedling establishment. In all three years, irrigation water with 5.5 dS/m salinity reduced the maximum leaf area index (LAI<sub>m</sub>) and chlorophyll content the most significantly when compared with other salinity treatments. However, compared with the control treatment (CK), a slight increase in LAI<sub>m</sub> and chlorophyll content was observed with 3~4 dS/m salinity. Saline water improved tomato quality, including fruit density, soluble solid, total acid, vitamin C and the sugar-acid ratio. There was a positive relationship between the overall tomato quality and salinity of irrigation water, as analyzed by principal component analysis (PCA). The tomato yield decreased with increased salinity. The 5.5 dS/m treatment reduced the tomato yield (Y<sub>t</sub>) by 22.4~31.1%, 12.6~28.0% and 11.7~27.3%, respectively in 2012, 2013 and 2014, compared with CK. Moreover, a significant (P≤0.01) coupling effect of salinity and soil matric potential on Y<sub>t</sub> was detected. Saline water caused Y<sub>t</sub> to increase more markedly when the lower limit of soil matric potential was controlled at a relatively lower level. The critical salinity level that produced significant increases in the BER<sub>i</sub> was 3 dS/m~4 dS/m. Following the increase in BER<sub>i</sub> under saline water irrigation, marketable tomato yield (Y<sub>m</sub>) decreased by 8.9%~33.8% in 2012, 5.1%~30.4% in 2013 and 10.1%~32.3% in 2014 compared with CK. In terms of maintaining the Y<sub>t</sub> and Y<sub>m</sub>, the salinity of irrigation water should be controlled under 4 dS/m, and the lower limit of soil matric potential should be greater than -20 kPa.</p></div
Efficient Palladium/1,10-Phenanthroline-Catalyzed Reductive Carbonylation of Mono- and Dinitroarenes to Urethanes in Phosphonium Salt Ionic Liquids
The highly reactive and selective reductive carbonylation of mono- and dinitroarenes to the corresponding mono- and diurethanes was carried out in the presence of a PdCl2/Phen catalytic system, using PSIL110[C14H29(C6H13)3P+PF6−] as the ionic liquid under mild reaction conditions. No cocatalyst is required
Data_Sheet_1_Parsing the contributions of negative affect vs. aversive motivation to cognitive control: an experimental investigation.docx
IntroductionPunishment is a powerful drive that fosters aversive motivation and increases negative affect. Previous studies have reported that this drive has the propensity to improve cognitive control, as shown by improved conflict processing when it is used. However, whether aversive motivation per se or negative affect eventually drives this change remains unclear because in previous work, the specific contribution of these two components could not be isolated.MethodsTo address this question, we conducted two experiments where we administered the confound minimized Stroop task to a large group of participants each time (N = 50 and N = 47 for Experiment 1 and 2, respectively) and manipulated punishment and feedback contingency using a factorial design. These two experiments were similar except that in the second one, we also measured awareness of feedback contingency at the subjective level. We reasoned that cognitive control would improve the most when punishment would be used, and the contingency between this motivational drive and performance would be reinforced, selectively.ResultsBoth experiments consistently showed that negative affect increased at the subjective level when punishment was used and the feedback was contingent on task performance, with these two effects being additive. In Experiment 1, we found that when the feedback was contingent on task performance and punishment was activated, conflict processing did not improve. In Experiment 2, we found that conflict processing improved when punishment was contingent on task performance, and participants were aware of this contingency.DiscussionThese results suggest that aversive motivation can improve conflict processing when participants are aware of the link created between punishment and performance.</p
The incidence of blossom-end rot (BER<sub>i</sub>) of tomato irrigated with saline waters of different electrical conductivity (EC) values across the 3 years.
<p>(At the same EC of irrigation water, the values of tomato BER incidence are the means from the five soil matric potential treatments. In the same year, means followed by the same letter do not differ significantly at the 5% level according to a LSD test. Each value is the mean ± SD).</p
Dates of transplanting, treatment, first harvest, and harvest duration.
<p>Dates of transplanting, treatment, first harvest, and harvest duration.</p
The maximum leaf area index (LAI<sub>m</sub>) produced by tomato plants subjected to soil and water salinity treatments across the 3 years.
<p>Note: The values of LAI<sub>m</sub> in three years are means of 3 replications. In the same column and in the same year, means followed by the same letter (a, b) do not differ significantly at the 5% level by LSD.</p><p>The maximum leaf area index (LAI<sub>m</sub>) produced by tomato plants subjected to soil and water salinity treatments across the 3 years.</p
Efficient Method for the Synthesis of Chiral Pyrrolidine Derivatives via Ring-Closing Enyne Metathesis Reaction
A series of new pyrrolidine derivatives were prepared directly in very good yields, from the substrates containing a basic or nucleophilic N
atom via ring-closing enyne metathesis reaction under mild reaction conditions. Moreover, the reaction occurs smoothly without the presence
of ethylene gas
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