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1.
Artigo em Inglês | MEDLINE | ID: mdl-33009696

RESUMO

The addition of π-allylmetal complexes to carbonyls is the most important route to homoallylic alcohols. This study reports the first photocatalytic generation of π-allyltitanium complexes via a radical strategy. This novel strategy enables the three-component allylation of carbonyls with 1,3-butadiene, providing rapid access to valuable homoallylic alcohols across over 60 examples. The exceptional regio- and diastereo-selectivity provided by dual photoredox/Ti catalysis is comparable to that of the Cr catalyzed Nozaki-Hiyama-Kishi (NHK) allylation reaction.

2.
Org Lett ; 22(20): 8127-8131, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33026812

RESUMO

We developed an approach for direct selective hydroxylation of heterobenzylic methylenes to secondary alcohols avoiding overoxidation to ketones by using a KOBu-t/DMSO/air system. Most reactions could reach completion in several minutes to give hydroxylated products in 41-76% yields. Using DMSO-d6, this protocol resulted in difunctionalization of heterobenzylic methylenes to afford α-deuterated secondary alcohols (>93% incorporation). By employing this method, active pharmaceutical ingredients carbinoxamine and doxylamine were synthesized in two steps in moderate yields.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33035162

RESUMO

Graph convolutional networks (GCNs), which generalize CNNs to more generic non-Euclidean structures, have achieved remarkable performance for skeleton-based action recognition. However, there still exist several issues in the previous GCN-based models. First, the topology of the graph is set heuristically and fixed over all the model layers and input data. This may not be suitable for the hierarchy of the GCN model and the diversity of the data in action recognition tasks. Second, the second-order information of the skeleton data, i.e., the length and orientation of the bones, is rarely investigated, which is naturally more informative and discriminative for the human action recognition. In this work, we propose a novel multi-stream attention-enhanced adaptive graph convolutional neural network (MS-AAGCN) for skeleton-based action recognition. The graph topology in our model can be either uniformly or individually learned based on the input data in an end-to-end manner. This data-driven approach increases the flexibility of the model for graph construction and brings more generality to adapt to various data samples. Besides, the proposed adaptive graph convolutional layer is further enhanced by a spatial-temporal-channel attention module, which helps the model pay more attention to important joints, frames and features. Moreover, the information of both the joints and bones, together with their motion information, are simultaneously modeled in a multi-stream framework, which shows notable improvement for the recognition accuracy. Extensive experiments on the two large-scale datasets, NTU-RGBD and Kinetics-Skeleton, demonstrate that the performance of our model exceeds the state-of-the-art with a significant margin.

4.
Cell Cycle ; : 1-11, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33064974

RESUMO

MiR-34a is associated with diabetic retinopathy (DR). This article aims to demystify the role of miR-34a in DR. We established a DR model by streptozocin injection. Rat retinal vascular endothelial cells (RVECs) were treated with high glucose (HG) to induce DR. The pathological changes of retinal tissues and blood-retinal vascular barrier permeability of DR rats were assessed by HE staining and Evans-Blue leak test. The expression of gene and protein was evaluated by quantitative real-time PCR or western blot. MTT assay and flow cytometry were performed to detect proliferation and apoptosis. The relationship between miR-34a and SIRT1 was evaluated using luciferase reporter assay. MiR-34a was up-regulated and SIRT1 was down-regulated in retinal tissues of DR rats and HG-induced RVECs. MiR-34a silencing improved DR by regulating apoptosis and VEGF expression in DR rats. Furthermore, miR-34a interacted with SIRT1 and suppressed SIRT1 expression. MiR-34a overexpression inhibited proliferation and promoted apoptosis of RVECs, which was effectively abolished by SIRT1 up-regulation. In summary, our data demonstrate that miR-34a promotes apoptosis of RVECs by targeting SIRT1 in DR rats. Our findings suggest that miR-34a/SIRT1 axis could be a valuable target for DR therapies.

5.
Genome Res ; 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060171

RESUMO

The advances of large-scale genomics studies have enabled compilation of cell type-specific, genome-wide DNA functional elements at high resolution. With the growing volume of functional annotation data and sequencing variants, existing variant annotation algorithms lack the efficiency and scalability to process big genomic data, particularly when annotating whole genome sequencing variants against a huge database with billions of genomic features. Here, we develop VarNote to rapidly annotate genome-scale variants in large and complex functional annotation resources. Equipped with a novel index system and a parallel random-sweep searching algorithm, VarNote shows substantial performance improvements (two to three orders of magnitude) over existing algorithms at different scales. It supports both region-based and allele-specific annotations, and introduces advanced functions for the flexible extraction of annotations. By integrating massive base-wise and context-dependent annotations in the VarNote framework, we introduce three efficient and accurate pipelines to prioritize the causal regulatory variants for common diseases, Mendelian disorders and cancers.

6.
J Immunol ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028619

RESUMO

A hallmark of secondary hemophagocytic lymphohistiocytosis (sHLH), a severe form of cytokine storm syndrome, is the emergence of overactivated macrophages that engulf healthy host blood cells (i.e., hemophagocytosis) and contribute to the dysregulated inflammation-driven pathology. In this study, we show that depleting SIRPα (SIRPα-/-) in mice during TLR9-driven inflammation exacerbates and accelerates the onset of fulminant sHLH, in which systemic hemophagocytosis, hypercytokinemia, consumptive cytopenias, hyperferritinemia, and other hemophagocytic lymphohistiocytosis hallmarks were apparent. In contrast, mice expressing SIRPα, including those deficient of the SIRPα ligand CD47 (CD47-/-), do not phenocopy SIRPα deficiency and fail to fully develop sHLH, albeit TLR9-inflamed wild-type and CD47-/- mice exhibited hemophagocytosis, anemia, and splenomegaly. Although IFN-γ is largely considered a driver of hemophagocytic lymphohistiocytosis pathology, IFN-γ neutralization did not preclude the precipitation of sHLH in TLR9-inflamed SIRPα-/- mice, whereas macrophage depletion attenuated sHLH in SIRPα-/- mice. Mechanistic studies confirmed that SIRPα not only restrains macrophages from acquiring a hemophagocytic phenotype but also tempers their proinflammatory cytokine and ferritin secretion by negatively regulating Erk1/2 and p38 activation downstream of TLR9 signaling. In addition to TLR9 agonists, TLR2, TLR3, or TLR4 agonists, as well as TNF-α, IL-6, or IL-17A, but not IFN-γ, similarly induced sHLH in SIRPα-/- mice but not SIRPα+ mice. Collectively, our study suggests that SIRPα plays a previously unappreciated role in sHLH/cytokine storm syndrome pathogenesis by preventing macrophages from becoming both hemophagocytic and hyperactivated under proinflammation.

7.
Food Chem ; 341(Pt 2): 128254, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33039741

RESUMO

Different chemical states of nitrogen are present in many freshwater and marine ecosystems, and nitrite ions are one of the most toxic water-soluble nitrogen species. Developing an effective and convenient sensing method to constantly detect the concentration of nitrite has become a wide concern. Here, a novel near-infrared fluorescent probe (AAC) was designed and synthesized via the "covalent assembly" principle, showing excellent selectivity and high sensitivity for nitrite. A new nitrite-quantitative method was established with the help of AAC, and the detection limit of nitrite using the new method was as low as 6.7 nM. AAC was successfully applied for the quantitative detection of nitrite in real-world environmental and food samples (including river water and Chinese sauerkraut), and the detection results were essentially identical to the results obtained from the traditional Griess assay. Moreover, AAC was successfully applied for tracking nitrite in Escherichia coli by fluorescence imaging. Since nitrite can have devastating effects, the method established with AAC allowed us to "see" effectively about the water quality, food quality, etc.

8.
J Colloid Interface Sci ; 583: 605-613, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-33039859

RESUMO

Adsorbents based on CuI for π-complexative separation of C2H4/C2H6 have attracted widespread interests. However, they are still confronting some challenges, for example, (i) a low separation efficiency, resulted from the ineffective reduction of CuII to CuI along with aggregation, and (ii) poor stability due to the oxidation of CuI to inactive CuII. In this study, active Cu and auxiliary Co species are simultaneously encapsulated within the nanopores of MIL-101 using a double-solvent (DS) method to obtain CuCoM-DS. The Cu species at the interior of MIL-101 are homogeneously dispersed and can be completely reduced to CuI without any structural damage to MIL-101. The resulting CuCoM-DS exhibits a superior performance in C2H4/C2H6 separation not only to the pristine MIL-101, but to the counterpart samples of single Cu and/or Cu/Co at the exterior of MIL-101. The best sample of 1.5CuCoM-DS adsorbent is capable to adsorb 50.5 mL·g-1 of C2H4, and the C2H4/C2H6 selectivity is 2.6 at 100 kPa. Both C2H4 uptake and C2H4/C2H6 selectivity are higher than those reference samples. Moreover, 1.5CuCoM-DS preserves over 90% of fresh C2H4 uptake after the exposure to atmospheric air for 12 days. This study provides new design ideas for confining bimetallic sites in MOFs for broad applications.

9.
Sci Total Environ ; 755(Pt 2): 142595, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33049534

RESUMO

The mineralization of soil organic matter is closely related to climate change. Labile organic matter and microbial community are vital intrinsic factors in controlling the mineralization of soil organic matter. Regulation of soil aggregate size on dissolved organic matter (DOM), the cellobiose hydrolyzing microbial community, and their roles in organic matter mineralization remains unclear. The mineralization of organic matter in large macroaggregates (LMA, >2 mm), small macroaggregates (SMA, 0.25-2 mm), and microaggregates (MI, <0.25 mm) from an Ultisol treated with long-term non-fertilizers (Ck), chemical fertilizers (NPK) and animal manure (AM) was observed in this study. The concentration and structure of DOM, activity of ß-glucosidase, and the abundance, diversity, and community composition of GH1 (glycoside hydrolase family 1) microbial ß-glucosidase encoding genes were investigated. The cumulative CO2-C emissions occurred in the order LMA < SMA < MI in each fertilization treatment and followed the sequence Ck < NPK < AM in each size of aggregate. The concentration of DOM in the soil aggregates increased as the aggregate size decreased, while the structural complexity of DOM followed the opposite trend. The activity of ß-glucosidase in the smaller aggregates was higher than that in the larger aggregates, and the abundance and diversity of the GH1 microbial ß-glucosidase genes generally echoed the same trend. The dominant microbial classes harboring GH1 ß-glucosidase genes in the soil aggregates were Actinobacteria, Alphaproteobacteria, Gammaproteobacteria, Flavobacteria, Eurotiomycetes, and Sordariomycetes. The relative abundance of Actinobacteria, Sordariomycetes, and Eurotiomycetes revealed significant differences among the aggregates. Redundancy analysis confirmed that microbial GH1 ß-glucosidase community in the soil aggregates was primarily regulated by DOM concentration and pH. Structural equation modelling revealed that soil aggregates mainly regulated the ß-glucosidase activity and DOM concentration and then the abundance and diversity of the GH1 microbial ß-glucosidase genes in controlling organic matter mineralization.

10.
Ann Palliat Med ; 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-33040544

RESUMO

Crizotinib is the first-line drug for non-small cell lung cancer (NSCLC) patients who display anaplastic lymphoma kinase (ALK) rearrangement. With 60% overall response rate, crizotinib significantly prolongs median progression-free survival (ranged 8-10 months) of ALK rearrangement NSCLC patients. However, there are some adverse events from crizotinib, including diarrhea, weakness and nausea. Here, we describe a 47 years old woman with ALK-rearranged NSCLC who developed interstitial pneumonia (IP) induced by crizotinib. A female patient was diagnosed as the left lower lobe adenocarcinoma stage IV (T4N2M1, pleural metastasis) via lung biopsy and was detected wild-type EGFR and 18% ALK gene rearrangement from paraffin section. However, after going through 7 cycles of chemotherapy, she rejected chemotherapy because side effect and still experienced progression of the disease. Subsequently, crizotinib was prescribed as a targeted therapy. After 32 days, visible reduction in size was observed on the pulmonary mass and metastases found in brain and liver, but the patient presented drug-induced level 4 interstitial pneumonia. In a nutshell, the curative effect of crizotinib is worthy of note, but clinicians should also weigh the advantages and disadvantages, prior its usage.

11.
FEMS Microbiol Lett ; 367(19)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33021644

RESUMO

This study reports the development and optimization of a real-time loop-mediated isothermal amplification (qLAMP) method for rapid detection of Acetobacter aceti strain in red wine samples. Our results showed that the primers and probes designed for 16S rRNA were effective for A. aceti detection. The quantification limit of real-time polymerase chain reaction (qPCR) and qLAMP in pure culture was 2.05 × 101 colony forming units (CFU) mL-1. qLAMP had a sensitivity of 6.88 × 101 CFU mL-1 in artificially contaminated Changyu dry red wine (CDRW) and Changyu red wine (CRW), and 6.88 × 102 CFU mL-1 in artificially contaminated Greatwall dry red wine (GDRW), which was 10 times higher than that of qPCR. In conclusion, this newly developed qLAMP is a reliable, rapid and accurate method for the detection and quantification of A. aceti species in red wine samples. Furthermore, our work provides a standard reference method for the quantitative detection of A. aceti and other acetic acid bacteria during the fermentation and storage of red wine samples.

12.
Physiol Plant ; 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32981119

RESUMO

To copy with highly heterogeneous light environment, plants can regulate photosynthesis locally and systemically, thus maximizing the photosynthesis of individual plants. Therefore, we speculated that local weak light may induce the improvement of photosynthesis in adjacent illuminated leaves in plants. In order to test this hypothesis, maize seedlings were partially shaded, and gas exchange, chlorophyll a fluorescence and biochemical analysis were carefully assessed. It was shown that local shading exacerbated the declines in the photosynthetic rates, chlorophyll contents, electron transport and carbon assimilation-related enzyme activities in shaded leaves as plants growth progressed. While, the decreases of these parameters in adjacent illuminated leaves of shaded plants were considerably alleviated compared to the corresponding leaves of control plants. Obviously, the photosynthesis in adjacent illuminated leaves in shaded plants was improved by local shading, and the improvement in adjacent lower leaves was larger than that in adjacent upper ones. As growth progressed, local shading induced higher abscisic acid contents in shaded leaves, but it alleviated the increase in the abscisic acid contents in adjacent leaves in shaded plants. Moreover, the difference in sugar content between shaded leaves and adjacent illuminated ones was gradually increased. Consequently, local weak light suppressed the photosynthesis in shaded leaves, while it markedly improved the photosynthesis of adjacent illuminated ones. Sugar gradient between shaded leaves and adjacent illuminated ones might play a key role in photosynthetic regulation of adjacent illuminated leaves. This article is protected by copyright. All rights reserved.

13.
Virol Sin ; 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32986229

RESUMO

Healthcare workers (HCWs) are at high risk of occupational exposure to the new pandemic human coronavirus, SARS-CoV-2, and are a source of nosocomial transmission in airborne infectious isolation rooms (AIIRs). Here, we performed comprehensive environmental contamination surveillance to evaluate the risk of viral transmission in AIIRs with 115 rooms in three buildings at the Shanghai Public Health Clinical Center, Shanghai, during the treatment of 334 patients infected with SARS-CoV-2. The results showed that the risk of airborne transmission of SARS-CoV-2 in AIIRs was low (1.62%, 25/1544) due to the directional airflow and strong environmental hygiene procedures. However, we detected viral RNA on the surface of foot-operated openers and bathroom sinks in AIIRs (viral load: 55.00-3154.50 copies/mL). This might be a source of contamination to connecting corridors and object surfaces through the footwear and gloves used by HCWs. The risk of infection was eliminated by the use of disposable footwear covers and the application of more effective environmental and personal hygiene measures. With the help of effective infection control procedures, none of 290 HCWs was infected when working in the AIIRs at this hospital. This study has provided information pertinent for infection control in AIIRs during the treatment of COVID-19 patients.

14.
Sci Total Environ ; 751: 141644, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32866830

RESUMO

Rapeseed (Brassica napus L.) is extremely sensitive to both boron (B) and phosphorus (P) deficiencies. Application of chemical fertilizers is generally considered to be an effective agronomic practice to improve crop productivity, and it also affects soil bacterial community. However, there are few studies of the effects of balanced B and P fertilizer applications on crop yield and bacterial communities. In the present study, field experiments with five P application rates (0, 45, 90, 135 and 180 kg P2O5 ha-1) and four B application rates (0, 4.5, 9 and 18 kg Na2B4O7·5H2O ha-1) were conducted in 2016-2017 and 2017-2018 to investigate their effects on seed yield and P use efficiency (PUE) of B. napus. The smallest seed yields were obtained when B or P fertilizers were not applied (P90B0 or P0B9). Balanced B and P applications benefitted yields. The P45B4.5 treatment produced greater seed yield and PUE than the P45B18 treatment, and the P180B18 treatment produced greater seed yield and PUE than the P180B4.5 treatment. Sequencing of 16S rRNA genes revealed that the P90B9 treatment had greater soil bacterial diversity, and a different bacterial community composition, compared with the P90B0 or P0B9 treatments. Overall, our results underline the importance of balanced B and P nutrition for maximal seed yield of B. napus and the effects of B and P fertilizers on the soil bacterial community of B. napus.

15.
Int J Nanomedicine ; 15: 6279-6294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32904047

RESUMO

Introduction: Because of the increased production and application of manufactured Nano-TiO2 in the past several years, it is important to investigate its potential hazards. TiO2 is classified by IARC as a possible human carcinogen; however, the potential mechanism of carcinogenesis has not been studied clearly. The present study aimed to investigate the mechanism of DNA damage in rat lung and extra-pulmonary organs caused by TiO2nanoparticles. Methods: In the present study, SD rats were exposed to Nano-TiO2 by intratracheal injection at a dose of 0, 0.2, or 1 g/kg body weight. The titanium levels in tissues were detected by ICP-MS. Western blot was used to detect the protein expression levels. The DNA damage and oxidative stress were detected by comet assay and ROS, MDA, SOD, and GSH-Px levels, respectively. Results: The titanium levels of the 1 g/kg group on day-3 and day-7 were significantly increased in liver and kidney as well as significantly decreased in lung compared to day-1. ROS and MDA levels were statistically increased, whereas SOD and GSH-Px levels were statistically decreased in tissues of rats in dose-dependent manners after Nano-TiO2 treatment. PI3K, p-AKT/AKT, and p-FOXO3a/FOXO3a in lung, liver, and kidney activated in dose-dependent manners. The levels of DNA damage in liver, kidney, and lung in each Nano-TiO2 treatment group were significantly increased and could not recover within 7 days. GADD45α, ChK2, and XRCC1 in liver, kidney, and lung of rats exposed to Nano-TiO2 statistically increased, which triggered DNA repair. Conclusion: This work demonstrated that Ti could deposit in lung and enter extra-pulmonary organs of rats and cause oxidative stress, then trigger DNA damage through activating the PI3K-AKT-FOXO3a pathway and then promoting GADD45α, ChK2, and XRCC1 to process the DNA repair.

16.
Clin Transl Sci ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32905646

RESUMO

Reduced expression of the uptake transporter, OCTN1 (SLC22A4), has been reported as a strong predictor of poor event-free and overall survival in multiple cohorts of patients with acute myeloid leukemia (AML) receiving the cytidine nucleoside analog, cytarabine (Ara-C). To further understand the mechanistic basis of interindividual variability in the functional expression of OCTN1 in AML, we hypothesized a mechanistic connection to DNA methylation-based epigenetic repression of SLC22A4. We found increased basal SLC22A4 methylation was associated with decreased Ara-C uptake in AML cell lines. Pre-treatment with hypomethylating agents, 5-azacytidine, or decitabine, restored SLC22A4 mRNA expression, increased cellular uptake of Ara-C, and was associated with increased cellular sensitivity to Ara-C compared with vehicle-treated cells. Additionally, lower SLC22A4 methylation status was associated with distinct clinical advantages in both adult and pediatric patients with AML. These findings suggest a regulatory mechanism is involved in the interindividual variability in response to Ara-C, and provides a basis for the integration of hypomethylating agents into Ara-C-based treatment regimens.

17.
Cancer Med ; 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32888392

RESUMO

OBJECTIVE: To compare the survival outcomes of local ablation (LA) and partial nephrectomy (PN) for T1N0M0 renal cell carcinoma (RCC). METHOD: We identified 38,155 T1N0M0 RCC patients treated with PN or LA in 2004-2016 from the retrospective Surveillance, Epidemiology, and End Results databases. Among them, there were 4656 LA and 33,499 PN. A Cox proportional hazards regression model, cause-specific Cox regression and Fine and Gray sub-distribution hazard ratio (sHR) with inverse probability of treatment weighting (IPTW) adjusting was utilized to compare the effects of LA vs PN on all-, RCC-, and non-RCC-caused mortality. RESULTS: Within the IPTW analysis, patients who underwent PN experienced a better overall survival (OS) (HR, 1.56; 95% CI, 1.40-1.74; P < .001) and cancer-specific survival (CSS) (HR, 2.21; 95% CI, 1.62-2.98; P < .001) than LA patients. In the subgroup of patients >85 years (HR, 1.14; 95% CI, 0.73-1.79, P = .577), chromophobe RCC (HR, 1.68; 95% CI, 0.94-3.00, P = .078), and tumor size <2 cm (HR, 1.21; 95% CI, 0.95-1.53, P = .126), the OS showed no significant difference between LA and PN. No significant difference in CSS between LA and PN was observed in the subgroup of chromophobe RCC (HR, 0.34; 95% CI, 0.03-3.97, P = .389), and tumor size <2 cm (HR, 1.83; 95% CI, 0.92-3.64, P = .084). For patients >85 years (sHR, 0.89; 95% CI, 0.52-1.27, P = .520) and tumor size <2 cm (sHR, 1.14; 95% CI, 0.94-1.38, P = .200), the non-RCC-specific mortality was not significantly different in PN and LA cohorts, however, for the chromophobe RCC, the LA showed a worse non-RCC mortality than PN (HR, 1.72; 95% CI, 1.06-2.79, P = .028). CONCLUSION: PN showed a better prognosis than LA in T1N0M0 RCC treatment, but LA and PN showed a comparable OS in elderly patients (>85), small RCC (<2 cm) and chromophobe RCC.

18.
Photodiagnosis Photodyn Ther ; : 101980, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32866632

RESUMO

The aim of this study was to demonstrate the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) as an alternative treatment in cutaneous squamous cell carcinoma (cSCC) patients who are not fit for surgery. Thirty-three invasive cSCC patients who, for some reasons, cannot undergo surgery were enrolled in this study. All patients received plum blossom needle (PBN) pretreated ALA-PDT combined with topical application of 5% imiquimod cream. Two patients dropped the study because of severe pain and two patients discontinue treatment due to lack of response. Of 29 patients, who completed the treatment, 5 patients had complete response after 2 to 9 sessions of PDT and these patients had no recurrence till 18 months after treatment. Twenty-four patients achieved partial response and are satisfied with treatment outcome in terms of decreased symptoms and improved quality of life. PBN pretreated PDT in combination with topical imiquimod may be a viable treatment option for non resectable cSCC lesions.

19.
Poult Sci ; 99(9): 4521-4529, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32867996

RESUMO

The objective of this study was to investigate the effects of replacing antibiotics with a combination of plant essential oils on the growth performances and gastrointestinal health of broilers. A total of 720 1-day-old male AA broilers were randomly divided into 3 treatments: the control treatment (CON), the Aureomycin supplementation treatment (AGP), and the combined plant oils supplementation treatment (POC), with a 42-D period feeding procedure. Growth performances, carcass performances, intestinal sections, and cecal microbiota were investigated. Results indicated that POC supplementation decreased the feed conversion ratio compared with CON and AGP treatments, though not significantly. No significant differences were found for feed intake, BW gain, and culling rate among the 3 treatments (P > 0.05). In addition, no significant differences were seen on carcass performance. For the aspects of intestinal section, POC supplementation did not make significant effects on intestinal wall thickness, villus heights, crypt depths, and the ratio of villus heights/crypt depths compared with CON and AGP treatments. Cecal microbiota results demonstrated that bacterial diversity and some representative probiotic bacteria were significantly increased in numbers (P < 0.05) after POC supplementation. In conclusion, the combination of essential oils promoted intestinal health through improving gut bacterial diversity and probiotic bacteria, as well as improving feed conversion ratio of broilers. These results indicated that the combination of essential oils may benefit the gastrointestinal health and be applied as an antibiotic alternative.

20.
Nat Commun ; 11(1): 4789, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963247

RESUMO

Hydroxide exchange membrane fuel cells offer possibility of adopting platinum-group-metal-free catalysts to negotiate sluggish oxygen reduction reaction. Unfortunately, the ultrafast hydrogen oxidation reaction (HOR) on platinum decreases at least two orders of magnitude by switching the electrolytes from acid to base, causing high platinum-group-metal loadings. Here we show that a nickel-molybdenum nanoalloy with tetragonal MoNi4 phase can catalyze the HOR efficiently in alkaline electrolytes. The catalyst exhibits a high apparent exchange current density of 3.41 milliamperes per square centimeter and operates very stable, which is 1.4 times higher than that of state-of-the-art Pt/C catalyst. With this catalyst, we further demonstrate the capability to tolerate carbon monoxide poisoning. Marked HOR activity was also observed on similarly designed WNi4 catalyst. We attribute this remarkable HOR reactivity to an alloy effect that enables optimum adsorption of hydrogen on nickel and hydroxyl on molybdenum (tungsten), which synergistically promotes the Volmer reaction.

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