239 research outputs found
Untersuchungen zur Verringerung von direkten Bekämpfungsmaßnahmen bei einigen Obstarten im biologischen Anbau
In the search for methods of reducing direct pest control in organic fruit growing, several farmers in South Tirol and Austria who have experience in this field were visited. At the same time, various cultivars of apple, pear and peach were observed in the research orchard of the Institute for Fruit Production and Horticulture at the University of Agricultural Sciences in Vienna. Clear differences among varieties with regard to their susceptibility to important pests and diseases were readily observable. The necessity of testing cultivars in organically managed systems using a minimum of direct plant protection was emphasized by many farmers. The farmer's experience and our own observations demonstrated that soil management, fertilization, rootstocks, forming and pruning also influence plant health and need to be taken more precisely into account in organic farming. Other important issues still to be considered include the study of suitable complementary plants for fruit trees and the connection between soil and tree health
Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor
Metallaphotoredox catalysis is a powerful and versatile synthetic platform that enables cross-couplings under mild conditions without the need for noble metals. Its growing adoption in drug discovery has translated into an increased interest in sustainable and scalable reaction conditions. Here, we report a continuous-flow approach to metallaphotoredox catalysis using a heterogeneous catalyst that combines the function of a photo- and a nickel catalyst in a single material. The catalyst is embedded in a packed-bed reactor to combine reaction and (catalyst) separation in one step. The use of a packed bed simplifies the translation of optimized batch reaction conditions to continuous flow, as the only components present in the reaction mixture are the substrate and a base. The metallaphotoredox cross-coupling of sulfinates with aryl halides was used as a model system. The catalyst was shown to be stable, with a very low decrease of the yield (≈1% per day) during a continuous experiment over seven days, and to be effective for C–O arylations when carboxylic acids are used as nucleophile instead of sulfinates
'Preconditioning' with Low Dose Lipopolysaccharide Aggravates the Organ Injury/Dysfunction Caused by Hemorrhagic Shock in Rats
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedRS is supported by the Program Science without Borders, CAPES Foundation, Ministry of Education of Brazil, Brasilia/DF, Brazil; NSAP is, in part, supported by the Bart’s and The London Charity (753/1722). The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no 608765, from the William Harvey Research Foundation and University of Turin (Ricerca Locale ex-60%). This work contributes to the Organ Protection research theme of the Barts Centre for Trauma Sciences, supported by the Barts and The London Charity (Award 753/1722
Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications
Superparamagnetic iron oxide nanoparticles
can providemultiple benefits for biomedical applications
in aqueous environments such asmagnetic separation or
magnetic resonance imaging. To increase the colloidal
stability and allow subsequent reactions, the introduction
of hydrophilic functional groups onto the particles’
surface is essential. During this process, the original
coating is exchanged by preferably covalently bonded
ligands such as trialkoxysilanes. The duration of the
silane exchange reaction, which commonly takes more
than 24 h, is an important drawback for this approach. In
this paper, we present a novel method, which introduces
ultrasonication as an energy source to dramatically
accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove
the generic character, different functional groups were
introduced on the surface including polyethylene glycol
chains, carboxylic acid, amine, and thiol groups. Their
colloidal stability in various aqueous buffer solutions as
well as human plasma and serum was investigated to
allow implementation in biomedical and sensing
applications.status: publishe
Gas-phase composition and secondary organic aerosol formation from standard and particle filter-retrofitted gasoline direct injection vehicles investigated in a batch and flow reactor
Gasoline direct injection (GDI) vehicles have recently been identified as a
significant source of carbonaceous aerosol, of both primary and secondary
origin. Here we investigated primary emissions and secondary organic aerosol
(SOA) from four GDI vehicles, two of which were also retrofitted with a
prototype gasoline particulate filter (GPF). We studied two driving test
cycles under cold- and hot-engine conditions. Emissions were characterized by
proton transfer reaction time-of-flight mass spectrometry (gaseous
non-methane organic compounds, NMOCs), aerosol mass spectrometry (sub-micron
non-refractory particles) and light attenuation measurements (equivalent
black carbon (eBC) determination using Aethalometers) together with
supporting instrumentation. Atmospheric processing was simulated using the
PSI mobile smog chamber (SC) and the potential aerosol mass oxidation flow
reactor (OFR). Overall, primary and secondary particulate matter (PM) and
NMOC emissions were dominated by the engine cold start, i.e., before thermal
activation of the catalytic after-treatment system. Trends in the
SOA oxygen to carbon ratio (O : C) for OFR and SC were
related to different OH exposures, but divergences in the H : C remained
unexplained. SOA yields agreed within experimental variability between the
two systems, with a tendency for higher values in the OFR than in the SC (or,
vice versa, lower values in the SC). A few aromatic compounds dominated the
NMOC emissions, primarily benzene, toluene, xylene isomers/ethylbenzene and
C3-benzene. A significant fraction of the SOA was explained by those
compounds, based on comparison of effective SOA yield curves with those of
toluene, o-xylene and 1,2,4-trimethylbenzene determined in our OFR, as well
as others from literature. Remaining discrepancies, which were smaller in the
SC and larger in the OFR, were up to a factor of 2 and may have resulted from
diverse reasons including unaccounted precursors and matrix effects. GPF
retrofitting significantly reduced primary PM through removal of refractory
eBC and partially removed the minor POA fraction. At cold-started conditions
it did not affect hydrocarbon emission factors, relative chemical composition
of NMOCs or SOA formation, and likewise SOA yields and bulk composition
remained unaffected. GPF-induced effects at hot-engine conditions
deserve attention in further studies.</p
Comparison of the effects of three insulinotropic drugs on plasma insulin levels after a standard meal
WSTĘP. Porównanie działania repaglinidu, glipizydu i glibenklamidu
na wydzielanie insuliny i glukozy po posiłku próbnym zawierającym 500 kcal.
MATERIAŁ I METODY. Do krzyżowej, randomizowanej, podwójnie ślepej
próby zakwalifikowano 12 pacjentów z wczesną cukrzycą typu 2 (średnia wartość
HbA1c 6,1%) oraz 12 osób jako grupę kontrolną. Chorzy losowo otrzymali placebo,
2 mg repaglinidu, 5 mg glipizydu i 5 mg glibenklamidu. Leki podawano po wzorcowym
posiłku próbnym, zawierającym 500 kcal. Badania kolejnych leków wykonywano po
okresie wydalania poprzedniego z organizmu (7–12 dni).
WYNIKI. Wszystkie trzy leki miały jednakowy wpływ na całkowite
posiłkowe wydzielanie insuliny (pole pod krzywą [AUC, area under the curve]
-15-240 min). Zauważono jednak wyraźne różnice we wczesnym wydzielaniu insuliny
(AUC -15-30 min): u badanych bez cukrzycy zarówno repaglinid, jak i glipizyd zwiększały
wydzielanie insuliny odpowiednio o około 61 i 34% w porównaniu z placebo. Wśród
chorych na cukrzycę różnica ta wynosiła odpowiednio 37 i 47%. W obu grupach stwierdzono
istotną różnicę między glipizydem a glibenklamidem, natomiast repaglinid był skuteczniejszy
niż glibenklamid tylko wśród zdrowych pacjentów bez cukrzycy. Wszystkie leki skutecznie
obniżały całkowite stężenie glukozy AUC u chorych na cukrzycę i bez niej. Jednak
wśród badanych bez cukrzycy repaglinid okazał się znamiennie skuteczniejszy niż
glibenklamid. Różnicy takiej nie stwierdzono u chorych na cukrzycę, prawdopodobnie
ze względu na częstsze występowanie insulinooporności w tej grupie.
WNIOSKI. Repaglinid i glipizyd, ale nie glibenklamid, znacząco
poprawiły wczesne wydzielanie insuliny po standardowym posiłku, zarówno wśród
badanych bez cukrzycy, jak i wśród chorych na cukrzycę z zachowaną funkcją komórek
b trzustki.INTRODUCTION. To compare the effects of repaglinide,
glipizide, and glibenclamide on insulin secretion
and postprandial glucose after a single standard
500-kcal test meal.
MATERIAL AND METHODS. A total of 12 type 2 diabetic
patients with early diabetes (mean HbA1c of
6.1%) and 12 matched control subjects were enrolled
in this randomized, double-blind, crossover trial.
Subjects received placebo, 2 mg repaglinide, 5 mg
glipizide, and 5 mg glibenclamide in a random fashion
during the trial. Administration of each drug
was followed by a single standard 500-kcal test meal. A washout period of 7–12 days existed between the
four study visits.
RESULTS. All three drugs were equally effective on
the total prandial insulin secretion (area under the
curve [AUC] –15 to 240 min). However, clear differences
were noted in the early insulin secretion (AUC
–15 to 30 min); both repaglinide and glipizide increased
secretion in nondiabetic subjects by ~61 and
34%, respectively, compared with placebo. In the
diabetic patients, the difference versus placebo was
37 and 47%, respectively. The difference between
glipizide and glibenclamide reached significance in
both groups of subjects, whereas repaglinide was
more effective than glibenclamide only in the healthy
nondiabetic subject group. All three drugs were
effective in decreasing total glucose AUC in the nondiabetic
and diabetic population. In the nondiabetic
subjects, however, repaglinide was significantly
more effective than glibenclamide. The differences
disappeared in the diabetic subjects, probably as
a result of increased prevalence of insulin resistance
in this group.
CONCLUSIONS. Repaglinide and glipizide but not
glibenclamide significantly enhanced the early insulin
secretion in both nondiabetic and diabetic subjects
with preserved b-cell function after a single
standard meal
Intraligand charge transfer enables visible-light-mediated nickel-catalyzed cross-coupling reactions
We demonstrate that several visible-light mediated carbon–heteroatom cross-couplings can be carried out using a photoactive NiII precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups (Ni(Czbpy)Cl2). The activation of this precatalyst towards cross-couplings follows a hitherto undisclosed mechanism that is different from previously reported light-responsive nickel complexes that were reported to undergo metal-to-ligand charge transfer. Theoretic and spectroscopic investigations revealed that irradiation of Ni(Czbpy)Cl2 with visible-light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-couplings. The heterogeneous catalyst shows stable performance in a packed-bed flow reactor during a week of continuous operation
Trace Metals in Soot and PM2.5from Heavy-Fuel-Oil Combustion in a Marine Engine
Heavy fuel oil (HFO) particulate matter (PM) emitted by marine engines is known to contain toxic heavy metals, including vanadium (V) and nickel (Ni). The toxicity of such metals will depend on the their chemical state, size distribution, and mixing state. Using online soot-particle aerosol mass spectrometry (SP-AMS), we quantified the mass of five metals (V, Ni, Fe, Na, and Ba) in HFO-PM soot particles produced by a marine diesel research engine. The in-soot metal concentrations were compared to in-PM2.5measurements by inductively coupled plasma-optical emission spectroscopy (ICP-OES). We found that <3% of total PM2.5metals was associated with soot particles, which may still be sufficient to influence in-cylinder soot burnout rates. Since these metals were most likely present as oxides, whereas studies on lower-temperature boilers report a predominance of sulfates, this result implies that the toxicity of HFO PM depends on its combustion conditions. Finally, we observed a 4-to-25-fold enhancement in the ratio V:Ni in soot particles versus PM2.5, indicating an enrichment of V in soot due to its lower nucleation/condensation temperature. As this enrichment mechanism is not dependent on soot formation, V is expected to be generally enriched within smaller HFO-PM particles from marine engines, enhancing its toxicity
Insulin Detemir in the Treatment of Type 1 and Type 2 Diabetes
Insulin detemir is a soluble long-acting human insulin analogue at neutral pH with a unique mechanism of action. Following subcutaneous injection, insulin detemir binds to albumin via fatty acid chain, thereby providing slow absorption and a prolonged metabolic effect. Insulin detemir has a less variable pharmacokinetic profile than insulin suspension isophane or insulin ultralente. The use of insulin detemir can reduce the risk of hypoglycemia (especially nocturnal hypoglycemia) in type 1 and type 2 diabetic patients. However, overall glycemic control, as assessed by glycated hemoglobin, is only marginally and not significantly improved compared with usual insulin therapy. The weight gain commonly associated with insulin therapy is rather limited when insulin detemir is used. In our experience, this new insulin analogue is preferably administrated at bedtime but can be proposed twice a day (in the morning and either before the dinner or at bedtime). Detemir is a promising option for basal insulin therapy in type 1 or type 2 diabetic patients
The association between foot-care self efficacy beliefs and actual foot-care behaviour in people with peripheral neuropathy: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>People with diabetes and peripheral neuropathy often do not implement the foot-care behavioural strategies that are suggested by many health professionals. The concept of self-efficacy has been shown to be an effective predictor of behaviour in many areas of health. This study investigated the relationships between foot-care self-efficacy beliefs, self-reported foot-care behaviour and history of diabetes-related foot pathology in people with diabetes and loss of protective sensation in their feet.</p> <p>Methods</p> <p>Ninety-six participants were included in this cross-sectional study undertaken in a regional city of Australia. All participants had diabetes and clinically diagnosed loss of protective sensation in their feet. The participants completed a self-report pen-paper questionnaire regarding foot-care self efficacy beliefs (the "Foot Care Confidence Scale") and two aspects of actual foot-care behaviour-preventative behaviour and potentially damaging behaviour. Pearson correlation coefficients were then calculated to determine the association between foot-care self-efficacy beliefs and actual reported foot-care behaviour. Multiple analysis of variance was undertaken to compare mean self-efficacy and behaviour subscale scores for those with a history of foot pathology, and those that did not.</p> <p>Results</p> <p>A small positive correlation (r = 0.2, p = 0.05) was found between self-efficacy beliefs and preventative behaviour. There was no association between self-efficacy beliefs and potentially damaging behaviour. There was no difference in self-efficacy beliefs in people that had a history of foot pathology compared to those that did not.</p> <p>Conclusion</p> <p>There is little association between foot-care self-efficacy beliefs and actual foot-care behaviour. The usefulness of measuring foot-care self-efficacy beliefs to assess actual self foot-care behaviour using currently available instruments is limited in people with diabetes and loss of protective sensation.</p
- …
