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1.
Food Chem ; 371: 131206, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34619635

RESUMO

A DIA-based quantitative proteomic strategy was used to investigate the effects of different cooking procedures (steaming and boiling) on pork meat quality. Results showed that steamed meats had higher redness, cohesion, springiness, but lower lightness, yellowness, shear force, hardness, chewiness and cooking loss than boiled meats. In total of 1608 proteins were identified and 103 proteins exhibited significant difference (fold change > 1.5, P < 0.05). These DAPs mainly involved in protein structure, metabolic enzyme, protein turnover and oxidation stress. ALDOC, PVALB, PPP1R14C, AMPD1, CRYAB and SOD1 were validated as potential indicators of color variations in cooked meat. CFL1, COL1A1, COL3A1, RTN4, NRAP, NT5C3A, and SOD1 might be potential biomarker for texture changes of cooked meats. Moreover, these validated proteins exhibited significant (P < 0.05) correlation with cooking loss and could be serve as candidate predictors for cooking loss changes of meats in different cooking procedures.

2.
Cell Death Dis ; 12(10): 883, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34580275

RESUMO

Protein phosphatase 6 (PP6) is a member of the PP2A-like subfamily, which plays significant roles in numerous fundamental biological activities. We found that PPP6C plays important roles in male germ cells recently. Spermatogenesis is supported by the Sertoli cells in the seminiferous epithelium. In this study, we crossed Ppp6cF/F mice with AMH-Cre mice to gain mutant mice with specific depletion of the Ppp6c gene in the Sertoli cells. We discovered that the PPP6C cKO male mice were absolutely infertile and germ cells were largely lost during spermatogenesis. By combing phosphoproteome with bioinformatics analysis, we showed that the phosphorylation status of ß-catenin at S552 (a marker of adherens junctions) was significantly upregulated in mutant mice. Abnormal ß-catenin accumulation resulted in impaired testicular junction integrity, thus led to abnormal structure and functions of BTB. Taken together, our study reveals a novel function for PPP6C in male germ cell survival and differentiation by regulating the cell-cell communication through dephosphorylating ß-catenin at S552.

3.
Food Res Int ; 148: 110614, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507758

RESUMO

A two-dimensional low-field nuclear magnetic resonance (LF-NMR) T1-T2 relaxation technique was developed to contrast the water status evolution during different cooking procedures (steam and boiling cooking). Meat quality, water distribution, microstructure and protein properties were determined. The results showed that steamed meats had lower cooking loss and shear force, but higher redness, proton relaxation intensity (T1 and T2) and proton density than boiled meats. The differences in water distribution between the two cooking procedures appeared at approximately 40 °C, with acceleration at 60 °C, and the most remarkable difference was shown at 80 °C. Boiling resulted in more damage to muscle structure and greater protein denaturation than steam cooking. Meanwhile, α-helixes and ß-turns increased, but ß-sheets and random coils decreased in steamed meats compared with boiled meats. Changes in microstructural and protein properties were closely associated with water status evolution in cooked meat during cooking.


Assuntos
Carne de Porco , Carne Vermelha , Animais , Culinária , Espectroscopia de Ressonância Magnética , Suínos , Água
4.
Artigo em Inglês | MEDLINE | ID: mdl-34369900

RESUMO

ABSTRACT: Circular RNAs (circRNAs) are reported to play pivotal regulatory roles in atherosclerosis (AS) progression. In the present study, we explored the biological role of circRNA ubiquitin specific peptidase 36 (circ_USP36; hsa_circ_0003204) in oxidized low-density lipoprotein (ox-LDL)-induced dysfunction of endothelial cells (ECs). RNA and protein levels were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot assay, respectively. Cell proliferation was analyzed by 5-Ethynyl-2'-deoxyuridine (EdU) assay and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry was conducted to analyze cell cycle progression and cell apoptosis. The release of tumor necrosis factor α (TNF-α) in the supernatant was measured by enzyme linked immunosorbent assay (ELISA). Cell death was evaluated by lactate dehydrogenase (LDH) assay. Intermolecular interaction was verified by dual-luciferase reporter assay. Circ_USP36 expression was significantly up-regulated in the serum of AS patients and ox-LDL-stimulated HUVECs than that in their corresponding controls. ox-LDL exposure inhibited the proliferation ability and cell cycle progression and triggered the apoptosis and inflammation of HUVECs, and these effects were largely overturned by the knockdown of circ_USP36. microRNA-197-3p (miR-197-3p) was a target of circ_USP36, and circ_USP36 knockdown-mediated protective role in ox-LDL-induced HUVECs was largely counteracted by the silence of miR-197-3p. miR-197-3p interacted with the 3' untranslated region (3'UTR) of roundabout guidance receptor 1 (ROBO1). Circ_USP36 knockdown reduced ROBO1 expression partly by up-regulating miR-197-3p in HUVECs. ROBO1 overexpression reversed miR-197-3p accumulation-mediated effects in ox-LDL-induced HUVECs. In conclusion, circ_USP36 interference alleviated ox-LDL-induced dysfunction in HUVECs by targeting miR-197-3p/ROBO1 axis.

5.
J Environ Manage ; 298: 113543, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392095

RESUMO

Algae based wastewater treatment has been considered as the most promising win-win strategy for nutrients removal and biomass accumulation. However, the poor linking between traditional wastewater treatment and algal cultivation limits the achievement of this goal. In this study, a novel combination of Fenton oxidation and algal cultivation (CFOAC) system was investigated for the treatment of chicken farm flushing wastewater (CFFW). Fenton oxidation (FO) was adopted to reduce the excessive ammonia nitrogen, which might inhibit the algal growth. The results showed that single FO pretreatment removed 70.5 %, 96.7 %, 86.1 %, and 96.2 % of TN, TAN, TP, and COD, respectively. The highest biomass (235.8 mg/L/d) and lipid (77.3 mg/L/d) productivities were achieved on optimized CFOAC system after 7 days batch cultivation. Accordingly, the nutrients removal efficiencies increased to almost 100 %. Further fatty acid profile analysis showed that algae grown on optimal CFOAC system accumulated a high level of total lipids (32.8 %) with C16-C18 fatty acid as the most abundant compositions (accounting for over 60.6 %), which were propitious to biodiesel production. In addition, this CFOAC system was magnified from 1 L flask to 50 L horizontal pipe photobioreactor (HPPB) in semi-continuously culture under optimal conditions. The average biomass and lipid productivities were 995.7 mg/L/d and 320.6 mg/L/d, respectively, when cultured at 6 days hydraulic retention time with 1/3 substitution every two days. These findings proved that the novel CFOAC system is efficient in nutrients removal, algal cultivation, and biomass production for advanced treatment of CFFW.


Assuntos
Microalgas , Águas Residuárias , Animais , Biocombustíveis , Biomassa , Galinhas , Fazendas , Nitrogênio/análise , Nutrientes
6.
Opt Lett ; 46(15): 3729-3732, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34329267

RESUMO

The measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector side-channel attacks. Moreover, it can be easily implemented combining with the matured decoy-state methods under current technology. It, thus, seems a very promising candidate in practical implementation of quantum communications. However, it suffers from a severe finite-data-size effect in most existing MDI-QKD protocols, resulting in relatively low key rates. Recently, Jiang et al. [Phys. Rev. A103, 012402 (2021).PLRAAN1050-294710.1103/PhysRevA.103.012402] proposed a double-scanning method to drastically increase the key rate of MDI-QKD. Based on Jiang et al.'s theoretical work, here we for the first time, to the best of our knowledge, implement the double-scanning method into MDI-QKD and carry out corresponding experimental demonstration. With a moderate number of pulses of 1010, we can achieve 150 km secure transmission distance, which is impossible with all former methods. Therefore, our present work paves the way toward practical implementation of MDI-QKD.

7.
Opt Lett ; 46(15): 3757-3760, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34329274

RESUMO

Digital signature is a key technique in information security, especially for identity authentications. Compared to classical correspondence, quantum digital signatures (QDSs) provide a considerably higher level of security. At present, its performance is limited by key generation protocols, which are fundamentally limited in terms of channel capacity. Based on the idea of twin-field quantum key distribution, this Letter presents a twin-field QDS protocol and details a corresponding security analysis. In its distribution stage, a specific key generation protocol, the sending-or-not-sending twin-field protocol, has been adopted. Besides, we present a systematic model to evaluate the performance of a QDS protocol and compare the performance of our protocol to other typical QDS protocols. Numerical simulation results show that the new protocol exhibits outstanding security and practicality compared to other existing protocols. Therefore, our protocol paves the way toward real-world applications of QDSs.

8.
Gene ; 800: 145837, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34274469

RESUMO

Diarrhoea is a widespread disease in captive rhesus macaques (Macaca mulatta) and a small proportion of individuals may experience persistent diarrhoea. Persistent diarrhoea can lead to a compromised immune system, intestinal inflammation and malnutrition. We analyzed the blood transcriptomes of 10 persistent diarrhoeal and 12 healthy rhesus macaques to investigate the gene expression differences between the two groups. We identified 330 DEGs between persistent diarrhoeal and healthy rhesus macaques. The 211 up-regulated DEGs in the diarrhoeal group were mainly enriched in immune-related and interleukin-related categories. Among them, three interleukin (IL) 18 related DEGs (IL18, IL18R1, and IL18BP) played important roles in actively regulating pro-inflammatory responses. Interestingly, the up- and down-regulated DEGs were both enriched in the same immune-related categories. Thus, we applied a new method to examine the distribution of DEGs in all child categories. We found that interleukin and T cell related categories were mainly occupied by up-regulated DEGs, while immunoglobulin production and B cell related categories were enriched by down-regulated DEGs. We also compared rhesus macaque DEGs with the DEGs of inflammatory bowel disease (IBD) humans and IBD mouse models and found that 30-40% of macaque DEGs were shared with IBD humans and mouse models. In conclusion, our results showed that there were significant immune differences between persistent diarrhoeal rhesus macaques and healthy macaques, which was similar to the expression differences in IBD patients and mouse models.


Assuntos
Diarreia/veterinária , Doenças Inflamatórias Intestinais/genética , Doenças dos Macacos/genética , Animais , Estudos de Casos e Controles , Diarreia/genética , Diarreia/imunologia , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Doenças Inflamatórias Intestinais/etiologia , Interleucinas/genética , Macaca mulatta , Masculino , Camundongos , Doenças dos Macacos/imunologia
9.
Chemosphere ; 283: 131216, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34182623

RESUMO

The pickling sludge produced from rolling process contains a large amount of Fe, Ca, Al as well as other metals. If these metals can be extracted and used, it will promote the recycling of pickling sludge. Herein, we proposed a two-step extraction method to extract Fe ions out from the pickling sludge, and then the extracted Fe was oxidized by H2O2 and prepared into Fe-containing coagulant in the presence of Na2HPO4 as stabilizer. The three main factors that affect the color removal efficiency and COD removal efficiency are identified as P:Fe ratio, H2O2 adding amount, and curing time. Results show that the optimal preparation conditions are: P:Fe = 0.05, H2O2 amount = 115%, and the curing time = 6 d, at which the color and COD removal efficiency reached 96.25% and 65.91%, respectively. The assessment of toxicity of the PPFC indicated that the content of harmful substances meets the thresholds in Chinese national standard GB141591-2016. The findings in this study are expected to provide new implications in treating different kinds of Fe-containing sludge.


Assuntos
Ferro , Esgotos , Compostos Férricos , Peróxido de Hidrogênio , Eliminação de Resíduos Líquidos
10.
Structure ; 29(8): 823-833.e5, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34161756

RESUMO

There is a clinical need for direct-acting antivirals targeting SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, to complement current therapeutic strategies. The main protease (Mpro) is an attractive target for antiviral therapy. However, the vast majority of protease inhibitors described thus far are peptidomimetic and bind to the active-site cysteine via a covalent adduct, which is generally pharmacokinetically unfavorable. We have reported the optimization of an existing FDA-approved chemical scaffold, perampanel, to bind to and inhibit Mpro noncovalently with IC50s in the low-nanomolar range and EC50s in the low-micromolar range. Here, we present nine crystal structures of Mpro bound to a series of perampanel analogs, providing detailed structural insights into their mechanism of action and structure-activity relationship. These insights further reveal strategies for pursuing rational inhibitor design efforts in the context of considerable active-site flexibility and potential resistance mechanisms.


Assuntos
Antivirais/química , Proteases 3C de Coronavírus/química , Inibidores de Proteases/química , Piridonas/química , SARS-CoV-2/enzimologia , Antivirais/farmacologia , COVID-19/tratamento farmacológico , COVID-19/virologia , Domínio Catalítico , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/metabolismo , Desenho de Fármacos , Simulação de Dinâmica Molecular , Estrutura Molecular , Inibidores de Proteases/farmacologia , Conformação Proteica , Multimerização Proteica , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia
11.
Food Res Int ; 145: 110401, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34112404

RESUMO

As a kind of promising resource, animal bone has been widely processed into functional foods. However, there is little research about the effect of particle size on the physicochemical properties and digestibility of yak bone powder (YBP), as well as its anti-osteoporosis activity. In this study, the YBP with median particle sizes (MPS) ranging from 19.68 to 128.37 µm were prepared, and their digestibility and anti-osteoporosis activity were investigated. The results showed that smaller MPS significantly increased water holding capacity and protein solubility without changing composition. The MPS reduction greatly promoted protein digestion, producing more peptides<3 kDa and free amino acids while decreased Ca2+ and P5+ release during gastrointestinal digestion. The in vivo results revealed the positive effect of YBP on ovariectomy-induced osteoporosis in rats. The bone mineral density of ovariectomized (OVX) rats was obviously improved by regulating bone turnover markers (B-ALP, OCN, S-CTX, ES and TRAP), thus potentially shedding light on osteoporosis remission. However, different MPS exhibited a weak effect on osteoporosis in OVX rats. Therefore, YBP could be produced in relatively large particle size without sacrificing food sensory quality, the processing time of which could also be shortened for higher productivity and lower cost.


Assuntos
Osteoporose , Animais , Osso e Ossos , Bovinos , Modelos Animais de Doenças , Feminino , Humanos , Ovariectomia , Tamanho da Partícula , Pós , Ratos
12.
Food Chem ; 357: 129765, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33957473

RESUMO

The oxidation and volatile constituents of bacon (which made of white pig (Duroc × Landrace × Yorkshire) and black pig (Beijing Black × Yorkshire)) during refrigerated storage were analyzed by thiobarbituric acid reactive substances (TBARS), total thiol groups, gas chromatography-mass spectrometry (GC-MS) and gas chromatography coupling with ion mobility spectrometry (GC-IMS). The TBARS value of tested samples increased while the total thiol groups decreased during 60 days storage (P < 0.05). Volatile fingerprint results were obtained by GC-MS and GC-IMS detector, the classes and contents of volatile compounds detected in WP bacon were much abundant than BP bacon. Higher phenols and acids concentrations were observed in WP bacon, while alcohols, ketones, and nitrogen-containing compounds were more determined in BP bacon. Besides, WP bacon was more notably affected by storage rather than BP bacon, and the difference of raw material is the main reason for the flavor in WP and BP bacon comparing with the storage process.

13.
Carbohydr Polym ; 266: 118099, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34044918

RESUMO

Although chondroitin sulfate calcium complex (CSCa) was claimed to have the bioactivity for bone care in vitro, its anti-osteoporosis bioactivity was little reported in vivo. Here, the effects of CSCa on osteoporosis rats were investigated. Results showed that, compared with the osteoporosis rats, CSCa could improve the bone mineral density and microstructure of femur, and change the bone turnover markers level in serum. 16S rRNA sequencing and metabolomics analysis indicated CSCa intervention altered the composition of gut microbiota along with metabolite profiles in ovariectomized rat faeces. The correlation analysis showed some gut microbiota taxa were significantly correlated with osteoporosis phenotypes and the enriched metabolites. Taken together, dietary CSCa intervention has the potential to alleviate the osteoporosis and related symptoms probably involving gut microbiota or the metabolite profiles as demonstrated in rats. This study provides some scientific evidence for the potential effects of CSCa as the food supplement on the osteoporosis.

14.
Sheng Wu Gong Cheng Xue Bao ; 37(4): 1260-1276, 2021 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-33973440

RESUMO

The unicellular green alga Haematococcus pluvialis is the best source of natural astaxanthin (AST) in the world due to its high content under stress conditions. Although high light (HL) can effectively induce AST biosynthesis, the specific mechanisms of light signal perception and transduction are unclear. In the current study, we used transcriptomic data of normal (N), high white light (W), and high blue light (B) to study the mechanisms of light inducing AST accumulation from the point of photoreceptors. The original data of 4.0 G, 3.8 G, and 3.6 G for N, W, and B were obtained, respectively, by the Illumina Hi-seq 2000 sequencing technology. Totally, 51 954 unigenes (at least 200 bp in length) were generated, of which, 20 537 unigenes were annotated into at least one database (NR, NT, KO, SwissProt, Pfam, GO, or KOG). There were 1 255 DEGs in the W vs N, 1 494 DEGs in the B vs N, and 1 008 DEGs in the both W vs N and B vs N. KEGG enrichment analysis revealed that photosynthesis, oxidative phosphorylation, carotenoid biosynthesis, fatty acids biosynthesis, DNA replication, nitrogen metabolism, and carbon metabolism were the significantly enriched pathways. Moreover, a large number of genes encoding photoreceptors and predicted interacting proteins were predicted in Haematococcus transcriptome data. These genes showed significant differences at transcriptional expression levels. In addition, 15 related DEGs were selected and tested by qRT-PCR and the results were significantly correlated with the transcriptome data. The above results indicate that the signal transduction pathway of "light signal - photoreceptors - interaction proteins - (interaction proteins - transcription factor/transcriptional regulator) - gene expression - AST accumulation" might play important roles in the regulation process, and provide reference for further understanding the transcriptional regulation mechanisms of AST accumulation under HL stress.


Assuntos
Clorófitas , Clorófitas/genética , Perfilação da Expressão Gênica , Transdução de Sinais/genética , Transcriptoma/genética , Xantofilas
15.
Food Chem ; 356: 129619, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33813204

RESUMO

Consumers have an increasing concern in the provenance of the foods they consume. Methods for discriminating geographical origins and species of cattle bone product are essential to provide veracious information for consumers and avoid the adulteration and inferior problems. In this study, 50 element contents of a total of 143 cattle bone samples from eight producing regions in China, were determined by inductively coupled plasma mass spectrometry (ICP-MS). Element contents were used as chemical indicators to discriminate species and geographical origins of cattle bone samples by multivariate data analysis, including hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). The K-fold cross validation accuracy for species and geographical origin discrimination was 99.3% and 94.5%, respectively. This study reveals that multi-element analysis accompanied by LDA is an effective technique to ensure the information reliability of cattle bone samples, and this strategy may be a potential tool for standardizing market.


Assuntos
Minerais/química , Animais , Produtos Biológicos/química , Bovinos , China , Análise por Conglomerados , Análise Discriminante , Espectrometria de Massas , Análise Multivariada , Reprodutibilidade dos Testes
16.
Shock ; 56(4): 611-620, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33756501

RESUMO

ABSTRACT: Vascular hypo-reactivity plays a critical role inducing organ injury during hemorrhagic shock. 17ß-estradiol (E2) can induce vasodilation to increase blood flow in various vascular beds. This study observed whether E2 can restore vascular hypo-reactivity induced by hemorrhagic shock, and whether E2 effects are associated with RhoA-Rho kinase (ROCK)-myosin light chain kinase phosphatase (MLCP) pathway. The hemorrhagic shock model (40 ±â€Š2 mm Hg for 1 h, resuscitation for 4 h) was established in ovary intact sham operation (OVI), ovariectomized (OVX), and OVX plus E2 supplement female mice. Intestinal microvascular loop was used to assess blood flow in vivo, mRNA expression and vascular reactivity in vitro. Hemorrhagic shock significantly reduced norepinephrine microvascular reactivity. Decreased microvascular reactivity was exacerbated by OVX and reversed by E2 supplement. U-46619 (RhoA agonist) increased microvascular reactivity, and C3 transferase (an ADP ribosyl transferase that selectively induces RhoA ribosylation) or Y-27632 (ROCK inhibitor) inhibited sham mice microvascular reactivity. Similarly, U-46619 increased microvascular reactivity in OVI and OVX mice following hemorrhagic shock, which was abolished by Y-27632 or concomitant incubation of okadaic acid (OA) (MLCP inhibitor) and Y-27632. In OVX plus E2 supplement mice with hemorrhagic shock, Y-27632 inhibited microvascular reactivity, which was abolished by concomitant U-46619 application. Lastly, hemorrhagic shock remarkably decreased intestinal loop blood flow, RhoA and ROCK mRNA expressions in vascular tissues in OVX females, but not in OVI females, which were reversed by E2 supplement. These results indicate that estrogen improves microvascular reactivity during hemorrhagic shock, and RhoA-ROCK signaling pathway may mediate E2 effects.

17.
BMC Med Imaging ; 21(1): 40, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33673821

RESUMO

BACKGROUND: The objective of this study was to analyze the accuracy of gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) for predicting microvascular invasion (MVI) in patients with small hepatocellular carcinoma (sHCC) preoperatively. METHODS: A total of 60 sHCC patients performed with preoperative Gd-EOB-DTPA-MRI in the Harbin Medical University Cancer Hospital from October 2018 to October 2019 were involved in the study. Univariate and multivariate analyses were performed by chi-square test and logistic regression analysis. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of Gd-EOB-DTPA-MRI were performed by receiver operating characteristic (ROC) curves. RESULTS: Univariate analysis indicated that alanine aminotransferase (≥ 39.00U/L), poorly differentiated pathology, and imaging features including grim enhancement, capsule enhancement, arterial halo sign and hepatobiliary features (tumor highly uptake, halo sign, spicule sign and brush sign) were associated with the occurrence of MVI (p < 0.05). Multivariate analysis revealed that rim enhancement and hepatobiliary spicule sign were independent predictors of MVI (p < 0.05). The area under the ROC curve was 0.917 (95% confidence interval 0.838-0.996), and the sensitivity was 94.74%. CONCLUSIONS: The morphologies of hepatobiliary phase imaging, especially the spicule sign, showed high accuracy in diagnosing MVI of sHCC. Rim enhancement played a significant role in diagnosing MVI of sHCC.

18.
Poult Sci ; 100(5): 101074, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33774373

RESUMO

This study was undertaken to discern the transmission characteristics of mcr-1 and blaCTX-M-type in one multidrug-resistant Escherichia coli LWY24 from chicken in China. The genetic profiles of LWY24 isolate were determined by conjugation, S1-pulsed-field gel electrophoresis, southern blot hybridization, and whole genome sequencing analysis. Meanwhile, co-transfer of plasmids in LWY24 isolate was screened by dual conjugation assays. The LWY24 isolate was identified as ST93, and harbored 3 conjugative plasmids, pLWY24J-3 (blaCTX-M-55-bearing IncFⅡ), pLWY24J-mcr-1 (mcr-1-carrying IncI2), and pLWY24J-4 (non-resistance-conferring IncI1), and one nonconjugative plasmid pLWY24 (blaCTX-M-14-containing IncHI2/IncHI2A). Numerous resistance genes, insertion sequences (especially IS26), and transposons were found in the 4 plasmids, suggesting that horizontal transmission have occurred by plasmid mating, homologous recombination, and transpositions. Under the selection pressure of cefotaxime and colistin or cefotaxime alone, the mcr-1-bearing plasmid and the blaCTX-M-55-harboring plasmid could be co-transferred at a similar frequency, with 8.00 × 10-4 or 9.00 × 10-4 transconjugants per donor cell, respectively. The specific shufflon region in mcr-1-encoding plasmid could generate up to 6 diverse PilV structures, which may further accelerate the horizontal transfer of plasmid. In conclusion, the transmission characteristics of mcr-1 and blaCTX-M-type in LWY24 isolate could due to clonal spread of ST93, selective pressure of cefotaxime, IS26-mediate homologous recombination and transposition, and the specific shufflon region.


Assuntos
Galinhas , Proteínas de Escherichia coli , Animais , Antibacterianos/farmacologia , China , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Genômica
19.
ACS Cent Sci ; 7(3): 467-475, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33786375

RESUMO

Starting from our previous finding of 14 known drugs as inhibitors of the main protease (Mpro) of SARS-CoV-2, the virus responsible for COVID-19, we have redesigned the weak hit perampanel to yield multiple noncovalent, nonpeptidic inhibitors with ca. 20 nM IC50 values in a kinetic assay. Free-energy perturbation (FEP) calculations for Mpro-ligand complexes provided valuable guidance on beneficial modifications that rapidly delivered the potent analogues. The design efforts were confirmed and augmented by determination of high-resolution X-ray crystal structures for five analogues bound to Mpro. Results of cell-based antiviral assays further demonstrated the potential of the compounds for treatment of COVID-19. In addition to the possible therapeutic significance, the work clearly demonstrates the power of computational chemistry for drug discovery, especially FEP-guided lead optimization.

20.
Small ; 17(17): e2006587, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33719156

RESUMO

The chlorine evolution reaction (CER) is a critical and commercially valuable electrochemical reaction in industrial-scale utilization, including the Chlor-alkali industry, seawater electrolysis, and saline wastewater treatment. Aiming at boosting CER electrocatalysis, hybrid IrO2 /TiO2 nanosheet arrays (NSAs) with rational surface and interfacial tuning strategies are proposed in this study. The IrO2 /TiO2 NSAs exhibit superb CER electrocatalytic activity with a low overpotential (44 mV) at 10 mA cm-2 , low Tafel slope of 40 mV dec-1 , high CER selectivity (95.8%), and long-term durability, outperforming most of the existing counterparts. The boosting mechanism is proposed that the aerophobic/hydrophilic surface engineering and interfacial electronic structure tuning of IrO2 /TiO2 are beneficial for the Cl- mass-transfer, Cl2 release, and Volmer-Heyvrosky kinetics during the CER. Practical saline wastewater treatment by using the IrO2 /TiO2 NSAs electrode is further conducted, demonstrating it has a higher p-nitrophenol degradation ratio (95.10% in 60 min) than that of other electrodes. The rational surface and interfacial engineering of IrO2 /TiO2 NSAs can open up a new way to design highly efficient electrocatalysts for industrial application and environmental remediation.

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