38 research outputs found
Effect of addition of exogenous enzymes in hypocaloric diet in broiler chicken on performance, biochemical parameters and meat characteristics
In developing countries, broiler farmers often use imbalanced energy diets, hence our study aims to evaluate the combined effect of addition of commercial exogenous enzymes (CEE), in low energy level corn/soybean meal based-diet on performance, serum biochemical parameters, meat characteristics in male and female of broiler chickens. A total of 120 one day old Hubbard F15 broiler chickens were divided on 2 groups (60 animals/group) with 5 replicates/group. The control group received a standard diet, while CEE group received the same diet supplemented with enzymes (250 g/ton). Addition of enzymes reduced significantly feed (p<0.001) and water intakes (p<0.05); in meantime, feed conversion ratio tended to be lower (p=0.08). No changes were observed in pH, protein or moisture contents of meat in both sexes broiler between CEE and control groups. No perturbation was found in all serum biochemical parameters in both sexes between CEE and control groups, except total protein and albumin levels were significantly higher in male birds fed enzymes when compared to male birds of the control group (p<0.001; p<0.01) respectively. Addition of enzymes allowed a decrease of 950 g/bird in feed intake for the total rearing period, hence save 337 âŹ/1000 birds; thus, use of CEE in hypocaloric diet enhances broilers feed efficiency and procures an economic benefit to farmers
Direct Hybridization of Polymer Exchange Membrane Surface Fuel Cell with Small Aqueous Supercapacitors
International audienc
Effect of temperature in bands structure, effective mass and correlation with magneto-transport properties in a nanostructure far-infrared detector superlattice
We report here the effect of temperature in bands structure performed in the envelope function formalism, effective mass and magneto- transport properties of n-type HgTe (d(1)=8.6 nm) /CdTe (d(2)=3.2 nm) superlattices (SLs). When d(2) increase the gap E-g(Gamma) decrease to zero, at the transition semiconductor to semimetal conductivity, and become negative accusing a semimetallic conduction after the point T'(d(2)T', ET'). d(2)T' and ET' increases with temperature and removes the transition to higher d(2). Eg(Gamma) increases from 48 meV at 4.2 K to 105 meV at 300K. The Fermi level is constant (E-F(2D) approximate to 90 meV) until 77K and increases to 167 meV at 300K. Our Theoretical calculations have provided good agreement with the experimental data. The formalism used here predicts that the system is semiconductor for our ratio d(1)/d(2) = 2.69, when d(2) < 100 nm. In our case, d(2)=3.2 nm and E-g (Gamma,77K) = 60 meV so this sample is a two-dimensional far-infrared detector semiconductor (12 mu m<lambda(c)<28 mu m).Idbaha, A.; Nafidi, A.; Khallouq, K.; Charifi, H.; Chaib, H.; MarĂ, B.; Mollar GarcĂa, MA.... (2013). Effect of temperature in bands structure, effective mass and correlation with magneto-transport properties in a nanostructure far-infrared detector superlattice. Journal of Optoelectronics and Advanced Materials. 15(11-12):1275-1279. http://hdl.handle.net/10251/84267S127512791511-1
Isovalent Substitution and Heat Treatments Control of Tc, Chain Oxygen Disorder and Structural Phase Transition in High Tc Superconductors (Y1-xNdx)SrBaCu3O6+z
We report here on the preparation, X-ray diffraction with Rietveld refinement,
AC magnetic susceptibility measurements and effect of heat treatments in
(Y1−xNdx )SrBaCu3O6+z. Each sample was subject to two types of heat treatment:
oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. For
each x, the [AO] heat treatment increases the orthorhombicity ! = (b − a)/(b + a)
(for 0 "x 0.2) and the distance d[Cu(1) (Sr/Ba)] (decrease Tc) for
x 0.25. When x increase from 0 to 1,
! decreases to 0 with transition from orthorhombic to tetragonal structure. ![O] decreases
with Tc[O]. However, Tc[AO] decreases with ![AO] until x = 0.2, increases
for x = 0.4 and after it decreases by 9.8 K to 77.2 K for x = 1 [AO]. Remarkable
correlations were observed between Tc(x) and the volume of the unit cell V (x); and
between "Tc(x) = Tc[AO]−Tc[O] and "!(x). A combination of several factors such
as decrease in d[Cu(1) (Sr/Ba)]; increase in cationic and chain oxygen ordering; the
number psh(x) of holes by Cu(2) O2 superconducting plans and in-phase purity for
the [AO] samples may account for the observed data.Morghi, R.; Nafidi, A.; Aboulkassim, A.; Chaib, H.; Charafi, H.; Ait Taleb, T.; MarĂ Soucase, B.... (2012). Isovalent Substitution and Heat Treatments Control of Tc, Chain Oxygen Disorder and Structural Phase Transition in High Tc Superconductors (Y1-xNdx)SrBaCu3O6+z. Journal of Low Temperature Physics. 1-10. doi:10.1007/s10909-012-0834-xS110Y. Tokura, H. Takagi, S. Uchida, A superconducting copper oxide compound with electrons as the charge carriers. Nature 337, 345â347 (1989)R.J. Cava, Structural chemistry and the local charge picture of copper oxide superconductors. Science 247, 656â662 (1990)B. Raveau, C. Michel, M. Hervieu, D. Grout, Crystal Chemistry of High-T c Superconducting Copper Oxides (Springer, Berlin, 1991), Chap. 1-3T. Wada, N. Suzuki, A. Maeda, T. Yabe, K. Uchinokura, S. Uchida, S. Tanaka, Preparation and properties of superconducting La1+x Ba2âx Cu3O y (0â€xâ€0.5) ceramics sintered in N2 gas atmosphere. Phys. Rev. B 39(13), 9126â9138 (1989)M. Izumi, T. Yabe, T. Wada, A. Maeda, K. Uchinokura, S. Tanaka, H. Asano, Structural properties of the superconductor LaBa2Cu3ây O7âz in the solid solution system La1+x Ba2âx Cu3ây O7âz . Phys. Rev. B 40(10), 6771â6786 (1989)H.M. Rietveld, A profile refinement method for nuclear and magnetic structures. J. Appl. Crystallogr. 2, 65â71 (1969)A. Nafidi, B. Bouallal, A. El Kaaouachi, H. Chaib, Remarkable influence of heat treatment on the structural and superconducting properties of LnSrBaCu3O6+z . IEEE Trans. Appl. Supercond. 17(02), 2969â2972 (2007)I.D. Brown, D. Altermatt, Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallogr., B Struct. Crystallogr. Cryst. Chem. 41(4), 244â247 (1985)I. Zelnay, A. Nafidi, C. Greaves, R. Suryanarayanan, Seebeck effect and neutron diffraction of NdSrBaCu3O6+z , effect of argon annealing. Physica C 231, 207â212 (1994
SARS-CoV-2 infection triggers more potent antibody-dependent cellular cytotoxicity (ADCC) responses than mRNA-, vector-, and inactivated virus-based COVID-19 vaccines
Neutralizing antibodies (NAbs) are elicited after infection and vaccination and have been well studied. However, their antibody-dependent cellular cytotoxicity (ADCC) functionality is still poorly characterized. Here, we investigated ADCC activity in convalescent sera from infected patients with wild-type (WT) severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or omicron variant compared with three coronavirus disease 2019 (COVID-19) vaccine platforms and postvaccination breakthrough infection (BTI). We analyzed ADCC activity targeting SARS-CoV-2 spike (S) and nucleocapsid (N) proteins in convalescent sera following WT SARS-CoV-2-infection (n = 91), including symptomatic and asymptomatic infections, omicron-infection (n = 8), COVID-19 vaccination with messenger RNA- (mRNA)- (BNT162b2 or mRNA-1273, n = 77), adenovirus vector- (n = 41), and inactivated virus- (n = 46) based vaccines, as well as post-mRNA vaccination BTI caused by omicron (n = 28). Correlations between ADCC, binding, and NAb titers were reported. ADCC was elicited within the first month postinfection and -vaccination and remained detectable for â„3 months. WT-infected symptomatic patients had higher S-specific ADCC levels than asymptomatic and vaccinated individuals. Also, no difference in N-specific ADCC activity was seen between symptomatic and asymptomatic patients, but the levels were higher than the inactivated vaccine. Notably, omicron infection showed reduced overall ADCC activity compared to WT SARS-CoV-2 infection. Although post-mRNA vaccination BTI elicited high levels of binding and NAbs, ADCC activity was significantly reduced. Also, there was no difference in ADCC levels across the four vaccines, although NAbs and binding antibody titers were significantly higher in mRNA-vaccinated individuals. All evaluated vaccine platforms are inferior in inducing ADCC compared to natural infection with WT SARS-CoV-2. The inactivated virus-based vaccine can induce N-specific ADCC activity, but its relevance to clinical outcomes requires further investigation. Our data suggest that ADCC could be used to estimate the extra-neutralization level against COVID-19 and provides evidence that vaccination should focus on other Fc-effector functions besides NAbs. Also, the decreased susceptibility of the omicron variant to ADCC offers valuable guidance for forthcoming efforts to identify the specific targets of antibodies facilitating ADCC.We thank the virology research center at the National Institute of Health (VRC-NIH) for providing the plasmids used to generate SARS-CoV-2 pseudoviruses and for providing HEK293T cells. We also thank the UREP students who assisted in the blood samples collection and coordination: Tala Jamaleddin, Huda Abdul Hameed, Amira Elsharafi, Fatima AlHamaydeh, Bushra Abu Halawa, Hadiya Khalid, Nasrin Cusman, Maram Ali, Hamas Fouda, Salma Mohamud, and Reham Kamal. This study was supported by partial funds from grant #NPRP11S-1212-170092 awarded to Dr. Yassine. GKN would like to acknowledge that this work was made possible by WHO grant number COVID-19-22-43; QUCG-BRC-23/24-170, and grant number UREP29-026-3-004 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the authors' responsibility
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Early intermittent hyperlipidaemia alters tissue macrophages to fuel atherosclerosis.
Hyperlipidaemia is a major risk factor of atherosclerotic cardiovascular disease (ASCVD). Risk of cardiovascular events depends on cumulative lifetime exposure to low-density lipoprotein cholesterol (LDL-C) and, independently, on the time course of exposure to LDL-C, with early exposure being associated with a higher risk1. Furthermore, LDL-C fluctuations are associated with ASCVD outcomes2-4. However, the precise mechanisms behind this increased ASCVD risk are not understood. Here we find that early intermittent feeding of mice on a high-cholesterol Western-type diet (WD) accelerates atherosclerosis compared with late continuous exposure to the WD, despite similar cumulative circulating LDL-C levels. We find that early intermittent hyperlipidaemia alters the number and homeostatic phenotype of resident-like arterial macrophages. Macrophage genes with altered expression are enriched for genes linked to human ASCVD in genome-wide association studies. We show that LYVE1+ resident macrophages are atheroprotective, and identify biological pathways related to actin filament organization, of which alteration accelerates atherosclerosis. Using the Young Finns Study, we show that exposure to cholesterol early in life is significantly associated with the incidence and size of carotid atherosclerotic plaques in mid-adulthood. In summary, our results identify early intermittent exposure to cholesterol as a strong determinant of accelerated atherosclerosis, highlighting the importance of optimal control of hyperlipidaemia early in life, and providing insights into the underlying biological mechanisms. This knowledge will be essential to designing effective therapeutic strategies to combat ASCVD