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81.
BACKGROUND: Brucellosis is a neglected tropical zoonosis allegedly reemerging in Middle Eastern countries. Infected ruminants are the primary source of human infection; consequently, estimates of the frequency of ruminant brucellosis are useful elements for building effective control strategies. Unfortunately, these estimates are lacking in most Middle East countries including Egypt. Our objectives are to estimate the frequency of ruminant brucellosis and to describe its spatial distribution in Kafr El Sheikh Governorate, Nile Delta, Egypt. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional study in which 791 sheep, 383 goats, 188 cattle milk tanks and 173 buffalo milk tanks were randomly selected in 40 villages and tested for the presence of antibodies against Brucella spp. The seroprevalence among different species was estimated and visualized using choropleth maps. A spatial scanning method was used to identify areas with significantly higher proportions of seropositive flocks and milk tanks. We estimated that 12.2% of sheep and 11.3% of goats in the study area were seropositive against Brucella spp. and that 12.2% and 12% of cattle and buffalo milk tanks had antibodies against Brucella spp. The southern part of the governorate had the highest seroprevalence with significant spatial clustering of seropositive flocks in the proximity of its capital and around the main animal markets. CONCLUSIONS/ SIGNIFICANCE: Our study revealed that brucellosis is endemic at high levels in all ruminant species in the study area and questions the efficacy of the control measures in place. The high intensity of infection transmission among ruminants combined with high livestock and human density and widespread marketing of unpasteurized milk and dairy products may explain why Egypt has one of the highest rates of human brucellosis worldwide. An effective integrated human-animal brucellosis control strategy is urgently needed. If resources are not sufficient for nationwide implementation, high-risk areas could be prioritized.  相似文献   
82.
In this study, 40 000 tissue culture-derived banana plants (vitroplants) at different growth stages, i.e. acclimatization, nursery and open field of banana (Musa spp.) cultivar ‘Grand Naine’ were screened for somaclonal variations using morphological investigations and molecular characterization. The total detected variants were grouped into 25 off-types (two of them died) in addition to the normal plant. Random Amplified Polymorphic DNA (RAPD) was carried out to study the differences among the normal cultivar ‘Grand Naine’ and its 23 variants using 17 arbitrary primers. Cluster analysis results revealed that ‘winged petiole’ and ‘deformed lamina’ were more related to the normal plant. However, ‘Giant plant’ and ‘weak plant’ related to each other and clustered with normal plant. According to principal coordinate analysis, most of the variants were aggregated nearly, whereas ‘variegated plant’ was separated apart from the other variants. This may reflect the genetic difference between ‘variegated plant’ and the other variants. The results obtained from both molecular and morphological analyses were in contiguous with better resolution when using the PCOORDA analysis than cluster analysis. Thus, it can be said that molecular markers can be used to eliminate the undesirable somaclonal variants from the lab without additional culture of the vitroplants in the field in order to save time and efforts.  相似文献   
83.
Hexavalent chromium (CrVI) is a heavy metal widely used in more than 50 industries. Nephrotoxicity is a major adverse effect of chromium poisoning. The present study investigated the potential renoprotective effect of lactoferrin (Lf) against potassium dichromate (PDC)-induced acute kidney injury (AKI) in rats. Beside, because previous studies suggest that interlukin-18 (IL-18) and insulin-like growth factor-1 (IGF-1) play important roles in promoting kidney damage, the present work aimed to evaluate the involvement of these two cytokines in PDC model of AKI and in the potential renoprotective effect of lactoferrin. Adult male albino Wistar rats were pretreated with Lf (200mg/kg/day, p.o.) or (300mg/kg/day, p.o.); the doses that are usually used in the experiment studies, for 14 days followed by a single dose of PDC (15mg/kg, s.c.). PDC caused significant increase in serum urea, creatinine, and total protein levels. This was accompanied with decreased renal glutathione content, and increased renal malondialdehyde, IL-18, IL-4, nuclear factor kappa B (NFκB), IGF-1, and the phosphorylated form of forkhead box protein O1 (FoxO1) levels. Moreover, normal expression IFN-γ mRNA and enhanced expression of TNF-α mRNA was demonstrated in renal tissues. Histopathological investigations provoked deleterious changes in the renal tissues. Tubular epithelial hyperplasia and apoptosis were demonstrated immunohistochemically by positive proliferating cell nuclear antigen (PCNA), Bax, and Caspase-3 expression, respectively. Pretreatment of rats with Lf in both doses significantly corrected all previously mentioned PDC-induced changes with no significant difference between both doses. In conclusion, the findings of the present study demonstrated the involvement of oxidative stress, inflammatory reactions, tubular hyperplasia and apoptosis in PDC-induced AKI. It suggested a role of IL-18 through stimulation of IL-4-induced inflammatory pathway, and IGF-1 through triggering FoxO1-induced cell proliferation. Moreover, the study revealed that Lf protected the kidney against Cr-induced AKI in rats and significantly showed antioxidant, anti-inflammatory, and anti-proliferative properties with down-regulation of IL-18 and IGF-1.  相似文献   
84.
The loop following helix α2 in glutathione transferase P1-1 has two conserved residues, Cys48 and Tyr50, important for glutathione (GSH) binding and catalytic activity. Chemical modification of Cys48 thwarts the catalytic activity of the enzyme, and mutation of Tyr50 generally decreases the kcat value and the affinity for GSH in a differential manner. Cys48 and Tyr50 were targeted by site-specific mutations and chemical modifications in order to investigate how the α2 loop modulates GSH binding and catalysis. Mutation of Cys48 into Ala increased KMGSH 24-fold and decreased the binding energy of GSH by 1.5 kcal/mol. Furthermore, the protein stability against thermal inactivation and chemical denaturation decreased. The crystal structure of the Cys-free variant was determined, and its similarity to the wild-type structure suggests that the mutation of Cys48 increases the flexibility of the α2 loop rather than dislocating the GSH-interacting residues. On the other hand, replacement of Tyr50 with Cys, producing mutant Y50C, increased the Gibbs free energy of the catalyzed reaction by 4.8 kcal/mol, lowered the affinity for S-hexyl glutathione by 2.2 kcal/mol, and decreased the thermal stability. The targeted alkylation of Cys50 in Y50C increased the affinity for GSH and protein stability. Characterization of the most active alkylated variants, S-n-butyl-, S-n-pentyl-, and S-cyclobutylmethyl-Y50C, indicated that the affinity for GSH is restored by stabilizing the α2 loop through positioning of the key residue into the lock structure of the neighboring subunit. In addition, kcat can be further modulated by varying the structure of the key residue side chain, which impinges on the rate-limiting step of catalysis.  相似文献   
85.

Purpose

The expansion of the electric vehicle (EV) market will bring changes in the type of environmental impact generated by the transport sector. This will be partially associated to the introduction of new technologies for energy storage and powertrains, including electric motors technology, which can play a critical role for the EV. To assure its optimal performance, key components and innovative materials are integrated in current motor designs. Such is the case of permanent magnets (PM), commonly made of rare-earth elements, which have a history of ecological concerns related to its mining. The goal of the paper is to study novel traction e-motors and to assess the influence of its components, in the environmental performance of the motor and the electric vehicle.

Methods

In this study, a life cycle assessment (LCA) is performed, including the manufacturing, use, and end of life stages of a traction electric motor for EV applications. A comparison is presented, where the rare-earth magnets are replaced by ferrite magnets, under several efficiency scenarios. Average European conditions are considered for framing the modeling. A functional unit of 1 km driven by the vehicle is used.

Results and discussion

Twelve impact categories were selected to present the potential environmental impact of the motors. Energy consumption during the use stage was identified as a hotspot responsible for an important share of the impact. The amount of energy consumed is highly dependent on the efficiencies of the powertrain, which is why improving efficiency should be regarded as crucial for decreasing the environmental damage produced by the motor. The use of rare-earth magnets during manufacturing does not represent a significant share of the impact, as they only take 2 % of the total mass. Other components, including laminations, housing and windings were instead recognized as more significant than the mangets, mainly for climate change, toxicity of humans, soil and water bodies, as well as metal depletion. The use of alternative materials for rare-earth magnets can contribute in the reduction of the potential impact, as long as the overall efficiency of the motor remains the same or increases.

Conclusions

Based on the study results, it can be concluded that the environmental performance of traction motor is closely tight to its efficiency. Selection of materials during design should focus more on preserving or improving the efficiency of the motor, than on materials with low environmental impact during production.
  相似文献   
86.
Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compound ketoisophorone (2,2,6-trimethyl-2-cyclohexene-1,4-dione) (1) by Marchantia polymorpha and Nicotiana tabacum cell suspension cultures produce the chiral products (6R)-levodione (2), (4R,5S)-4-hydroxy-3,3,5-trimethylcyclohexanone (3), and (4R,6R)-actinol (4) as well as the minor components (4R)-hydroxyisophorone (5) and (4S)-phorenol (6).  相似文献   
87.
The resinous material accumulated on aerial parts of Madia species is shown to consist mainly of diterpenes, containing a series of flavonoid aglycones. A6- and/or 8-O-substitution is characteristic for many of these flavonoids. Three known rare diterpenes were found and the structure elucidation of a diterpene with a new carbon skeleton, named madiaol, is reported.  相似文献   
88.
Ferry X  Brehin S  Kamel R  Landry Y 《Peptides》2002,23(8):1507-1515
Signaling pathways leading to exocytosis and arachidonate release from serosal mast cells by basic secretagogues, including cationic peptides, arise from the involvement of betagamma subunits from G(i2) and G(i3) GTP-binding proteins. The original concept that basic secretagogues directly interact with G proteins implicated the entry of secretagogues into mast cells. This has been demonstrated only for the neuropeptide substance P. Basic secretagogues might share a common mechanism of penetration with the newly described cell-penetrating peptides. The involvement of some membrane transporter or non-selective membrane receptor to basic secretagogues cannot be excluded.  相似文献   
89.
90.
Liver?X?Receptor (LXR) agonists have been reported as a potential treatment for atherosclerosis, Alzheimer’s disease and hepatitis C virus (HCV) infection. We have designed and synthesized a series of potent compounds based on a 1,2,4-triazole scaffold as novel LXR modulators. In cell-based cotransfection assays these compounds generally functioned as LXR agonists and we observed compounds with selectivity towards LXRα (7-fold) and LXRβ (7-fold) in terms of potency. Assessment of the effects of selected compounds on LXR target gene expression in HepG2 cells revealed that compounds 6a-b and 8a-b behaved as inverse agonists on FASN expression even though they were agonists in the LXRα and LXRβ cotransfection assays. Interestingly, these compounds had no effect on the expression of SREBP-1c confirming a unique LXR modulator pharmacology. Molecular docking studies and evaluation of ADME properties in-silico show that active compounds possess favorable binding modes and ADME profiles. Thus, these compounds may be useful for in vivo characterization of LXR modulators with unique profiles and determination of their potential clinical utility.  相似文献   
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