6,872 research outputs found
Enhanced photogeneration of polaron pairs in neat semicrystalline donor-acceptor copolymer films via direct excitation of interchain aggregates
We investigate the photogeneration
of polaron pairs (PPs) in neat
films of the semicrystalline donor–acceptor semiconducting
copolymer PCPDTBT. Carefully selecting the solution-processing procedures,
we obtain films with different amounts of crystallinity and interchain
aggregation. We compare the photogeneration of PPs between the films
by monitoring their photoinduced absorption in ultrafast pump–probe
experiments, selectively exciting nonaggregated or aggregated polymer
chains. The direct photoexcitation of interchain π-aggregates
results in prompt (<100 fs) charge generation. Compared to the
case where nonaggregated chains are excited, we find an 8-fold increase
in the prompt PP to singlet-exciton ratio. We also show that highly
crystalline lamellar nanostructures not containing π-stacked
or any light-absorbing aggregates do not improve the efficiency of
PP photogeneration. Our results show that light absorption from interchain
aggregates is highly beneficial for charge photogeneration in semiconducting
polymers and should be taken into account when optimizing film morphologies
for photovoltaic devices
NAFLD and Atherosclerosis Are Prevented by a Natural Dietary Supplement Containing Curcumin, Silymarin, Guggul, Chlorogenic Acid and Inulin in Mice Fed a High-Fat Diet
Non-alcoholic fatty liver disease (NAFLD) confers an increased risk of cardiovascular diseases. NAFDL is associated with atherogenic dyslipidemia, inflammation and renin-angiotensin system (RAS) imbalance, which in turn lead to atherosclerotic lesions. In the present study, the impact of a natural dietary supplement (NDS) containing Curcuma longa, silymarin, guggul, chlorogenic acid and inulin on NAFLD and atherosclerosis was evaluated, and the mechanism of action was examined. C57BL/6 mice were fed an HFD for 16 weeks; half of the mice were simultaneously treated with a daily oral administration (os) of the NDS. NAFLD and atherogenic lesions in aorta and carotid artery (histological analysis), hepatic expression of genes involved in the NAFLD (PCR array), hepatic angiotensinogen (AGT) and AT1R mRNA expression (real-time PCR) and plasma angiotensin (ANG)-II levels (ELISA) were evaluated. In the NDS group, steatosis, aortic lesions or carotid artery thickening was not observed. PCR array showed upregulation of some genes involved in lipid metabolism and anti-inflammatory activity (Cpt2, Ifng) and downregulation of some genes involved in pro-inflammatory response and in free fatty acid up-take (Fabp5, Socs3). Hepatic AGT, AT1R mRNA and ANG II plasma levels were significantly lower with respect to the untreated-group. Furthermore, NDS inhibited the dyslipidemia observed in the untreated animals. Altogether, these results suggest that NDS prevents NAFLD and atherogenesis by modulating the expression of different genes involved in NAFLD and avoiding RAS imbalance
The CMS RPC gas gain monitoring system: an overview and preliminary results
The status of the CMS RPC Gas Gain Monitoring (GGM) system developed at the
Frascati Laboratory of INFN (Istituto Nazionale di Fisica Nucleare) is reported
on. The GGM system is a cosmic ray telescope based on small RPC detectors
operated with the same gas mixture used by the CMS RPC system. The GGM gain and
efficiency are continuously monitored on-line, thus providing a fast and
accurate determination of any shift in working point conditions. The
construction details and the first result of GGM commissioning are described.Comment: 8 pages, 9 figures, uses lnfprepCMS.sty, presented by L. Benussi at
RPC07, Mumbai, INDIA 200
Metabolic abnormalities associated with initiation of systemic treatment for psoriasis: evidence from the Italian Psocare Registry.
Objective To evaluate variations in laboratory parameters and diagnoses of selected clinical conditions up to16 weeks after starting a new systemic psoriasis treatment for Psocare Registry enrollees.Design Prospective cohort study.Setting Italian public referral centres for psoriasis treatment.Patients First-time recipients (n = 10,539) of continuous systemic psoriasis treatment for at least 16 weeks.Main outcome measure Mean variations in (weeks 8 and 16) and proportions of patients reaching a clinicallymeaningful increase in serum levels (week 16) of total and low-density lipoprotein cholesterol, triglycerides, aspartateamino transferase, alanine amino transferase and creatinine, as well as week-16 cumulative incidences of newdiagnoses of diabetes mellitus and arterial hypertension.Results Mean cholesterol and triglyceride levels significantly increased in patients treated with acitretin orcyclosporine. Mean triglyceride levels also increased in efalizumab- and etanercept-treated patients. Meantransaminase values increased in methotrexate-treated patients, and mean aspartate amino transferase levelsincreased in infliximab-treated patients. The average serum creatinine value increased in cyclosporine-treatedpatients. Acitretin and cyclosporine were associated with risk of hypercholesterolaemia (odds ratios 1.51 and 1.34)and acitretin with risk of hypertriglyceridaemia (odds ratio 1.43). Methotrexate and infliximab were associated withrisk of more than doubling the upper normal aspartate amino transferase (odds ratios 2.06 and 1.87) and alanineamino transferase (odds ratios 2.38 and 1.74) values. The relative risk of developing arterial hypertension anddiabetes was increased for patients receiving cyclosporine (odds ratios 3.31 and 2.88).Conclusion Systemic treatments for psoriasis resulted in heterogeneous effects on the parameters analysed.Received: 1 September 2011; Accepted: 12 January 201
Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 5
In this contribution, new data concerning bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera Diplophyllum and Ptychostomum, the fungal genera Arrhenia, Gymnosporangium, and Sporidesmium and the lichen genera Arthonia, Coenogonium, Flavoplaca, Gyalolechia, Parmotrema, Peltigera, Pterygiopsis, Squamarina, Tornabea, and Waynea
Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays
We report the first reconstruction in hadron collisions of the suppressed
decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the
CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by
the CDF II detector at the Tevatron collider. We reconstruct a signal for the
B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard
deviations, and measure the ratios of the suppressed to favored branching
fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) =
[42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm
2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) =
-0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for
B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for
Publicatio
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
- …
