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91.
Aspergillus species are ubiquitous environmental moulds, with spores inhaled daily by most humans. Immunocompromised hosts can develop an invasive infection resulting in high mortality. There is, therefore, a pressing need for host-centric therapeutics for this infection. To address it, we created a multi-scale computational model of the infection, focused on its interaction with the innate immune system and iron, a critical nutrient for the pathogen. The model, parameterized using published data, was found to recapitulate a wide range of biological features and was experimentally validated in vivo. Conidial swelling was identified as critical in fungal strains with high growth, whereas the siderophore secretion rate seems to be an essential prerequisite for the establishment of the infection in low-growth strains. In immunocompetent hosts, high growth, high swelling probability and impaired leucocyte activation lead to a high conidial germination rate. Similarly, in neutropenic hosts, high fungal growth was achieved through synergy between high growth rate, high swelling probability, slow leucocyte activation and high siderophore secretion. In summary, the model reveals a small set of parameters related to fungal growth, iron acquisition and leucocyte activation as critical determinants of the fate of the infection.  相似文献   
92.
Peptide DIIADDEPLT (Pep19) has been previously suggested to improve metabolic parameters, without adverse central nervous system effects, in a murine model of diet-induced obesity. Here, we aimed to further evaluate whether Pep19 oral administration has anti-obesogenic effects, in a well-established high-fat diet-induced obesity model. Male Swiss mice, fed either a standard diet (SD) or high-fat diet (HFD), were orally administrated for 30 consecutive days, once a day, with saline vehicle or Pep19 (1 mg/kg). Next, several metabolic, morphological, and behavioral parameters were evaluated. Oral administration of Pep19 attenuated HFD body-weight gain, reduced in approximately 40% the absolute mass of the endocrine pancreas, and improved the relationship between circulating insulin and peripheral insulin sensitivity. Pep19 treatment of HFD-fed mice attenuated liver inflammation, hepatic fat distribution and accumulation, and lowered plasma alanine aminotransferase activity. The inguinal fat depot from the SD group treated with Pep19 showed multilocular brown-fat-like cells and increased mRNA expression of uncoupling protein 1 (UCP1), suggesting browning on inguinal white adipose cells. Morphological analysis of brown adipose tissue (BAT) from HFD mice showed the presence of larger white-like unilocular cells, compared to BAT from SD, Pep19-treated SD or HFD mice. Pep19 treatment produced no alterations in mice behavior. Oral administration of Pep19 ameliorates some metabolic traits altered by diet-induced obesity in a Swiss mice model.  相似文献   
93.
Aluminum (Al) is one of the most abundant elements on Earth, and its high extraction rate and industrial use make human exposure very common. As Al may be a human toxicant, it is important to investigate the effects of Al exposure, mainly at low doses and for prolonged periods, by simulating human exposure. This work aimed to study the effects of low-dose exposure to chloride aluminum (AlCl3) on the oxidative biochemistry, proteomic profile, and morphology of the major salivary glands. Wistar male rats were exposed to 8.3 mg/kg/day of AlCl3 via intragastric gavage for 60 days. Then, the parotid and submandibular glands were subjected to biochemical assays, proteomic evaluation, and histological analysis. Al caused oxidative imbalance in both salivary glands. Dysregulation of protein expression, mainly of those related to cytoarchitecture, energy metabolism and glandular function, was detected in both salivary glands. Al also promoted histological alterations, such as acinar atrophy and an increase in parenchymal tissue. Prolonged exposure to Al, even at low doses, was able to modulate molecular alterations associated with morphological impairments in the salivary glands of rats. From this perspective, prolonged Al exposure may be a risk to exposed populations and their oral health.  相似文献   
94.
95.
Scientometrics - The theme related to the oil production in the Brazilian territory is not limited to the extraction means, distribution and use of this product, and involves political, cultural...  相似文献   
96.
Clean Technologies and Environmental Policy - Maleic anhydride may be obtained from different technological routes, being the selective oxidation of benzene and oxidation of butane the only ones...  相似文献   
97.
98.
A method for bromine, chlorine, and iodine determination in soybean and related products was developed by inductively coupled plasma mass spectrometry (ICP-MS) after digestion by microwave-induced combustion (MIC). Samples were pressed as pellets and combusted using pressurized oxygen (20 bar) and ammonium nitrate solution (50 μL of 6 mol L?1) as the igniter. Analytes were absorbed in alkaline solution (100 mmol L?1 NH4OH), and a reflux step of 5 min, microwave power of 1,400 W, was applied after combustion in order to improve analyte recoveries. For Cl determination by ICP-MS, a dynamic reaction cell was used with ammonia as the reaction gas. The accuracy was evaluated using certified reference materials (CRMs) and spiked samples. Using MIC, the agreement with CRM values and spike recoveries was higher than 95 % for all analytes for certified reference materials of a similar composition (National Institute of Standards and Technology (NIST), corn bran and NIST, whole milk). Limits of detection were 0.03, 1.2, and 0.002 μg g?1 for Br, Cl, and I, respectively. The residual carbon content in the digests obtained after MIC procedure was lower than 0.5 %. Blanks were always negligible and no memory effects were observed. Digestion by MIC allowed processing up to eight samples by each run in 25 min with high efficiency of digestion providing a suitable medium for further bromine, chlorine, and iodine determination by ICP-MS.  相似文献   
99.
The objective of this study was to evaluate the factors that may affect conception rates (CR) following artificial insemination (AI) or embryo transfer (ET) in lactating Holstein cows. Estrous cycling cows producing 33.1 ± 7.2 kg of milk/d received PGF2α injections and were assigned randomly to 1 of 2 groups (AI or ET). Cows detected in estrus (n = 387) between 48 and 96 h after the PGF2α injection received AI (n = 227) 12 h after detection of estrus or ET (n = 160) 6 to 8 d later (1 fresh embryo, grade 1 or 2, produced from nonlactating cows). Pregnancy was diagnosed at 28 and 42 d after estrus, and embryonic loss occurred when a cow was pregnant on d 28 but not pregnant on d 42. Ovulation, conception, and embryonic loss were analyzed by a logistic model to evaluate the effects of covariates [days in milk (DIM), milk yield, body temperature (BT) at d 7 and 14 post-AI, and serum concentration of progesterone (P4) at d 7 and 14 post-AI] on the probability of success. The first analysis included all cows that were detected in estrus. The CR of AI and ET were different on d 28 (AI, 32.6% vs. ET, 49.4%) and 42 (AI, 29.1% vs. ET, 38.8%) and were negatively influenced by high BT (d 7) and DIM. The second analysis included only cows with a corpus luteum on d 7. Ovulation rate was 84.8% and was only negatively affected by DIM. Conception rates of AI and ET were different on d 28 (AI, 37.9% vs. ET, 59.4%) and 42 (AI, 33.8% vs. ET, 46.6%) and were negatively influenced by high BT (d 7). The third analysis included only ovulating cows that were 7 d postestrus. Conception rates of AI and ET were different on d 28 (AI, 37.5% vs. ET, 63.2%) and 42 (AI, 31.7% vs. ET, 51.7%) and were negatively influenced by high BT (d 7). There was a positive effect of serum concentration of P4 and a negative effect of milk production on the probability of conception for the AI group but not for the ET group. The fourth analysis was embryonic loss (AI, 10.8% vs. ET, 21.5%). The transfer of fresh embryos is an important tool to increase the probability of conception of lactating Holstein cows because it can bypass the negative effects of milk production and low P4 on the early embryo. The superiority of ET vs. AI is more evident in high-producing cows. High BT measured on d 7 had a negative effect on CR and embryonic retention.  相似文献   
100.
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