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1.
Opt Lett ; 48(11): 2901-2904, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37262239

RESUMO

A low-complexity scheme is proposed to realize irregular uniform quadrature amplitude modulation (QAM) formats with Gray mapping, which are named amplitude-division irregular QAM (AD-Ir-QAM) formats. Compared to conventional probabilistic shaping (PS) with the Maxwell-Boltzmann (MB) distribution (PS-MB), irregular QAM formats show a smaller peak-to-average power (PAPR) and achieve a better performance in systems with the peak-power constraint. Compared with irregular QAM formats realized by PS (PS-Ir-QAM), AD-Ir-QAM formats realize a more flexible rate adaptation and have a lower implementation complexity. Experimental results obtained in an unamplified coherent optical system show that, at a generalized mutual information (GMI) of 4.5 bits/2D-symbol, AD-Ir-100QAM achieves gains of 2.1 and 0.5 dB in the power budget over PS-MB-100QAM and PS-Ir-100QAM, respectively.

2.
Front Pharmacol ; 14: 1109279, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37089948

RESUMO

Introduction: This researcher focused at the evodiamine and dehydroevodiamine tissue distribution and structure-pharmacokinetics (PK) relationship after intravenous injection in mice. Methods: Using a transmembrane transport experiment, the permeability of evodiamine and dehydroevodiamine on Caco-2 cells was evaluated. The tissue distribution and pharmacokinetics (PK) of evodiamine and dehydroevodiamine in mice were studied. To comprehend the connection between structure and tissue distribution, physicochemical property evaluations and molecular electrostatic potential (MEP) calculations were performed. Results: Dehydroevodiamine's Papp values in vitro were 10-5 cm/s, whereas evodiamine's were 10-6 cm/s. At a dose of 5 mg/kg, the brain concentration of dehydroevodiamine was 6.44 times more than that of evodiamine. By MEP or physicochemical measures, the permeability difference between evodiamine and dehydroevodiamine is unaffected. The dihedral angle of the stereo-structure appears to be the main cause of the difference in tissue distribution ability between evodiamine and dehydroevodiamine. Discussion: Dehydroevodiamine has a dihedral angle of 3.71° compared to 82.34° for evodiamine. Dehydroevodiamine can more easily pass through the phospholipid bilayer than evodiamine because it has a more planar stereo-structure. Dehydroevodiamine is therefore more likely to pass cross the blood-brain barrier and enter the brain in a tissue-specific manner.

3.
Microbiol Spectr ; 11(1): e0335022, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36633436

RESUMO

Rhizobia can infect legumes and induce the coordinated expression of symbiosis and defense genes for the establishment of mutualistic symbiosis. Numerous studies have elucidated the molecular interactions between rhizobia and host plants, which are associated with Nod factor, exopolysaccharide, and T3SS effector proteins. However, there have been relatively few reports about how the host plant recognizes the outer membrane proteins (OMPs) of rhizobia to mediate symbiotic nodulation. In our previous work, a gene (Mhopa22) encoding an OMP was identified in Mesorhizobium huakuii 7653R, whose homologous genes are widely distributed in Rhizobiales. In this study, a germin-like protein GLP1 interacting with Mhopa22 was identified in Astragalus sinicus. RNA interference of AsGLP1 resulted in a decrease in nodule number, whereas overexpression of AsGLP1 increased the number of nodules in the hairy roots of A. sinicus. Consistent symbiotic phenotypes were identified in Medicago truncatula with MtGLPx (refer to medtr7g111240.1, the isogeny of AsGLP1) overexpression or Tnt1 mutant (glpx-1) in symbiosis with Sinorhizobium meliloti 1021. The glpx-1 mutant displayed hyperinfection and the formation of more infection threads but a decrease in root nodules. RNA sequencing analysis showed that many differentially expressed genes were involved in hormone signaling and symbiosis. Taken together, AsGLP1 and its homology play an essential role in mediating the early symbiotic process through interacting with the OMPs of rhizobia. IMPORTANCE This study is the first report to characterize a legume host plant protein to sense and interact with an outer membrane protein (OMP) of rhizobia. It can be speculated that GLP1 plays an essential role to mediate early symbiotic process through interacting with OMPs of rhizobia. The results provide deeper understanding and novel insights into the molecular interactive mechanism of a legume symbiosis signaling pathway in recognition with rhizobial OMPs. Our findings may also provide a new perspective to improve the symbiotic compatibility and nodulation of legume.


Assuntos
Medicago truncatula , Rhizobium , Proteínas de Membrana/metabolismo , Simbiose , Rhizobium/metabolismo , Raízes de Plantas/metabolismo , Proteínas de Plantas/genética , Medicago truncatula/genética , Medicago truncatula/metabolismo
4.
Opt Express ; 30(18): 33124-33135, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36242359

RESUMO

An asymmetric point-to-multipoint (PTMP) coherent architecture combined with a frequency aliasing recovery (FAR) algorithm is proposed for cost-constraint short-reach access networks. In this architecture, the uplink transmitters are simplified significantly with the uplink dual-polarization four-level pulse amplitude modulation (DP-PAM4) and downlink DP quadrature phase shift keying (DP-QPSK) asymmetric transmission design. Digital to analog converters (DACs) and radio frequency (RF) drivers are reduced by half, and in-phase and quadrature modulators (IQMs) are replaced by Mach-Zehnder modulators (MZMs), saving four MZ interferometers (MZIs). Furthermore, based on the asymmetric architecture, the FAR algorithm can recover signals from frequency aliasing caused by frequency offset (FO), even when half of the signal spectrum is aliased. This algorithm enables the asymmetric architecture to narrow down guard bands between subcarriers or even overlap the subcarriers, saving the receiver bandwidth at the aggregation/hub side. The performance of the asymmetric uplink DP-PAM4 transmission with the FAR algorithm is evaluated in both simualations and experiments. The effects of laser linewidths and IQ skew on the performance of the FAR algorithm are also analyzed. Simulation results show the algorithm can recover 16 Gbaud and 32 Gbaud signal from 8 GHz and 16 GHz aliasing, respectively. In the experiments with 10 km fiber transmissions, the FAR algorithm can recover 10 Gbaud signals from 5 GHz frequency aliasing, saving about 20.83% of the total receiver bandwidth in a 2-subcarrier system.

5.
Opt Express ; 30(16): 29409-29420, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36299116

RESUMO

We propose and experimentally demonstrate a coherent digital-analog radio-over-fiber (DA-RoF) system and achieve the transmission of Tb/s common public radio interface (CPRI)-equivalent data rate for fronthaul. The proposed coherent DA-RoF system includes DA-RoF modulation, demodulation and DA-RoF compatible coherent digital signal processing (DSP) blocks. A theoretical analysis of the DA-RoF scheme together with parameter optimization is accomplished as well. In the experiment, a 25 Gbaud DA-RoF signal with 1 Tb/s CPRI-equivalent data rate is transmitted in the system, satisfying the error vector magnitude (EVM) requirement for 256-quadrature amplitude modulation (QAM) signal transmission. With the symbol rate reduced to 10 Gbaud, an EVM below 2.5% is achieved, which meets the requirement for 1024-QAM transmission. The experimental results show that the coherent DA-RoF system is a promising solution for future fronthaul.

6.
Opt Express ; 29(18): 28852-28863, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34615006

RESUMO

A subcarrier-pairing entropy loading (SubP-EL) scheme with fairly low complexity is proposed for digital subcarrier-multiplexing (SCM) systems with colored signal-to-noise ratio (SNR) distributions. With the constraint of the target entropy, SubP-EL iteratively optimizes the entropy of subcarriers in pair. After convergence, SubP-EL can approach the optimal performance which is evaluated in simulations and experiments by comparison with the brute-force search method. Meanwhile the complexity of SubP-EL is significantly reduced compared with the brute-force search. In particular, in an 8-subcarrier system with five different SNRs, the complexity of SubP-EL is reduced by approximately a factor of 764, 95 and 13 with the entropy granularities of 0.05 bits/2D-symbol, 0.1 bits/2D-symbol and 0.2 bits/2D-symbol, respectively. The performance of SubP-EL is evaluated in simulations and experiments. In the experiments with 345 km fiber transmissions, the average NGMI gain of SubP-EL over the system without entropy loading is 0.0286 for different optical filtering cases.

7.
Pathol Res Pract ; 226: 153604, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34500372

RESUMO

Extracellular vesicles (EVs) are the structures that all cells release into the environment. They are separated by a lipid bilayer and contain the cellular components that release them. To date, most studies have been performed on EVs derived from cell supernatants or different body fluids, while the number of studies on EV isolation directly from tissues is still limited. Studies of EV isolation directly from tissues may provide us with better information. This review summarizes the role of EV in the extracellular matrix, the protocol for isolation of EV in the tissue interstitium, and the application of the protocol in different tissues.


Assuntos
Vesículas Extracelulares , Animais , Humanos
8.
Opt Express ; 29(11): 17522-17533, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34154293

RESUMO

In recent years, in order to increase the capacity and scalability of intra-datacenter (DC) transmission, the optical frequency comb (OFC) source has been considered promising to replace discrete lasers, aiming to reduce the cost of wavelength division multiplexing (WDM) transmission within DC. In this paper, an OFC based coherent architecture is proposed. An OFC, in the receiver side, is split by a splitter with a uniform power ratio and separately used as local oscillators (LOs) to detect the demultiplexed signals. The signal spectrum is copied onto every tone of the LO-OFC, and a large frequency offset (FO) tolerance is achieved. In addition, the required ADC sampling rate is the same as a system without FO. Extensive simulations are conducted. In the simulated coherent WDM transmission system, a 3-tone-OFC is used to provide 3 carriers, and an 11-tone-OFC is split and used to provide LO-OFCs. For a 64GBd polarization multiplexing 16 quadrature amplitude modulation (PM-16QAM) WDM transmission, the tolerances of FO are up to about ±0.3THz and ±0.374THz for the 1st/3rd signal, and the 2nd signal, respectively, below the pre-forward error correction (FEC) bit error rate (BER) level of 1.25×10-2. Moreover, the maximum tolerance of FO linearly increases with the number of effective tones in LO-OFC. Further, extensive experiments with back-to-back connection are conducted to verify the performance. The tolerance of FO is up to >36 GHz for 36GBd PM-16QAM transmission with a 3-tone-LO-OFC below the BER level of 1.25×10-2. The proposed OFC based coherent architecture is a promising solution for intra-DC interconnections with a large FO.

9.
Opt Express ; 29(6): 8076-8086, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33820260

RESUMO

We propose an algorithm to track the rotation of state of polarization (RSOP) for short-distance coherent subcarrier-multiplexing systems. 3 pilot tones are used to estimate RSOP matrices on a block-by-block basis and recover phase noise as well. An ultra-fast RSOP tracking ability using the proposed algorithm is demonstrated by experiment. Specifically, the bit error rate increases from 2.3×10-3 to 5.6×10-3 when the RSOP speed increases from 0 rad/s to 50 Mrad/s. We also demonstrate the robustness of the algorithm against polarization mode dispersion and polarization dependent loss.

10.
Zhongguo Zhong Yao Za Zhi ; 46(1): 162-170, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-33645066

RESUMO

To study the time-toxicity relationship and mechanism of Gardeniae Fructus extract on the hepatoxicity in rats. Rats were randomly divided into C group(0 day), D5 group(5 days), D12 group(12 days), D19 group(19 days), and D26 group(7 days recovery after 19 days of administration). The rats in normal group received normal saline through intragastric administration, and the rats in other groups received 10 g·kg~(-1 )Gardeniae Fructus extract through intragastric administration. After the final administration, the livers were collected. Hematoxylin-eosin staining was used to observe the histopathological changes in the liver tissue. Total liver proteins were extracted for proteomic analysis, detected by the Nano-ESI liquid-mass spectrometry system and identified by Protein Disco-very software. SIEVE software was used for relative quantitative and qualitative analysis of proteins. The protein-protein interaction network was constructed based on STRING. Cytoscape software was used for cluster analysis of differential proteins. Kyoto encyclopedia of genes and genomes(KEGG) database was used to perform enrichment signal pathway analysis. Pearson correlation analysis was performed for the screened differential protein expression and liver pathology degree score. The results showed that the severity of liver injury in D5, D12 and D19 groups was significantly higher than that in group C. The degree of liver damage in D5 group was slightly higher than that in D12 and D19 groups, with no significant difference between group D26 and group C. Totally 147 key differential proteins have been screened out by proteomics and mainly formed 6 clusters, involving in drug metabolism pathways, retinol metabolism pathways, proteasomes, amino acid biosynthesis pathways, and glycolysis/gluconeogenesis pathways. The results of Pearson correlation analysis indicated that differential protein expressions had a certain temporal relationship with the change of liver pathological degree. The above results indicated that the severity of liver damage caused by Gardeniae Fructus extract did not increase with time and would recover after drug with drawal. The above pathways may be related to the mechanism of liver injury induced by Gardeniae Fructus extract.


Assuntos
Medicamentos de Ervas Chinesas , Gardenia , Animais , Medicamentos de Ervas Chinesas/toxicidade , Frutas , Fígado , Proteômica , Ratos , Transdução de Sinais
11.
Opt Express ; 28(9): 13401-13413, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32403815

RESUMO

A degenerated look-up table-based perturbative nonlinearity compensation (DLUT-PNC) algorithm is proposed to compensate for intra-channel fiber nonlinearity. It can flexibly optimize the implementation complexity for probabilistically shaped (PS) signals with different shaping rates. In addition, we propose a homomorphic DLUT-PNC (HDLUT-PNC) scheme to further reduce the complexity. In simulations with a transmission distance of 1200-km for 70-GBaud PS-16QAM signals, both the performances of the DLUT-PNC and HDLUT-PNC are investigated and compared. The HDLUT-PNC scheme significantly reduces the table's input size, number of look-up operations and number of complex multipliers compared to the DLUT-PNC. Moreover, we also numerically investigate 56-Gbaud PS-32QAM signals with a transmission distance of 800-km, and the results are similar. Finally, the performance is verified in experiments for PS-16QAM signals with a transmission distance of 432-km.

12.
J Biosci ; 452020.
Artigo em Inglês | MEDLINE | ID: mdl-32385218

RESUMO

In this study, the regulatory effect of the overexpression of polarity protein Lgl2 on the nuclear export of influenza A virus nucleoprotein in infected cells was investigated. A stable Tet-Off inducible MDCK cell line expressing a fusion protein comprising Lgl2 and an enhanced yellow fluorescent protein were used. TCID50 analysis and neuraminidase activity analysis revealed that replication of influenza A virus was inhibited in Lgl2 overexpressing cells. By immunofluorescence microscopical observation at different time point post virus infection, a retention of NP in cellular nucleus was found in Lgl2 overexpressing cells. Compared with normal MDCK cells, change in claudin-1 distribution between cell contacts caused by Lgl2 overexpression impaired the barrier function of tight junction. These results suggest that changes in cell polarity induced by Lgl2 overexpressing will affect virus NP transportation.


Assuntos
Transporte Ativo do Núcleo Celular/genética , Proteínas do Citoesqueleto/genética , Interações Hospedeiro-Patógeno/genética , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/genética , Proteínas do Nucleocapsídeo/genética , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/virologia , Polaridade Celular , Claudina-1/genética , Claudina-1/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Cães , Regulação da Expressão Gênica , Humanos , Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A Subtipo H3N2/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Células Madin Darby de Rim Canino , Proteínas do Nucleocapsídeo/biossíntese , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Transfecção , Transgenes , Replicação Viral
13.
Food Sci Nutr ; 7(2): 764-772, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30847155

RESUMO

Distribution of lipids morphology and evolution of lipids during soy sauce production were studied. It was found that oil bodies fused and migrated to the outside of soybean cells after steamed, and further fused to cystidiums. And the model of soybean lipids distribution in soy sauce production was presented. Acid value increased to 34.4 mg KOH/g after koji fermentation, and it gradually decreased in the following fermentation. Linoleic acid (C18:2) decreased from 59.35% to 47.75% after 30 days of moromi fermentation. The contents of fatty acids from neutral lipids and free fatty acids increased to 20.98 and 13.47 mg/g, respectively, after moromi fermentation. Fatty acid of phospholipids increased to 8.34 mg/g during koji fermentation and reduced in the prior phase of moromi fermentation. The lipids model and analysis provide new insights into improving aroma of soy sauce and extraction lipids from soy sauce residue.

14.
Clin Res Hepatol Gastroenterol ; 42(3): e56-e59, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29150356

RESUMO

BACKGROUND: Biliary cryptococci infection is rare, which is frequently diagnosed by exploratory laparotomy, preoperative diagnosis is difficult. CASE PRESENTATION: A 14-year-old girl presented with intermittent jaundice for 6 years. She had no pruritus, anorexia, nausea or vomiting, fever, abdominal pain, or clay stools. Laboratory tests showed obstructive jaundice, eosinophilia, and increased IgE levels. The patient was ultimately diagnosed as Cryptococcal infection by bone marrow culture. The patient responded to antifungal therapy. CONCLUSION: Unnecessary surgical intervention was avoided by an early and accurate diagnosis. Cryptococcosis infection of bile duct should be highly suspected, when the children with obstructive jaundice have eosinophilia and increased IgE levels.


Assuntos
Criptococose/diagnóstico , Icterícia Obstrutiva/diagnóstico , Adolescente , Criptococose/complicações , Feminino , Humanos , Icterícia Obstrutiva/microbiologia
15.
Braz. j. microbiol ; 48(2): 305-313, April.-June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-839385

RESUMO

Abstract The aerobic degradation of aromatic compounds by bacteria is performed by dioxygenases. To show some characteristic patterns of the dioxygenase genotype and its degradation specificities, twenty-nine gram-negative bacterial cultures were obtained from sediment contaminated with phenolic compounds in Wuhan, China. The isolates were phylogenetically diverse and belonged to 10 genera. All 29 gram-negative bacteria were able to utilize phenol, m-dihydroxybenzene and 2-hydroxybenzoic acid as the sole carbon sources, and members of the three primary genera Pseudomonas, Acinetobacter and Alcaligenes were able to grow in the presence of multiple monoaromatic compounds. PCR and DNA sequence analysis were used to detect dioxygenase genes coding for catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenase. The results showed that there are 4 genotypes; most strains are either PNP (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is positive) or PNN (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is negative). The strains with two dioxygenase genes can usually grow on many more aromatic compounds than strains with one dioxygenase gene. Degradation experiments using a mixed culture representing four bacterial genotypes resulted in the rapid degradation of phenol. Determinations of substrate utilization and phenol degradation revealed their affiliations through dioxygenase genotype data.


Assuntos
Fenol/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/metabolismo , Filogenia , Pseudomonas , Poluentes do Solo/metabolismo , Acinetobacter , DNA Bacteriano/genética , DNA Bacteriano/química , DNA Ribossômico/genética , DNA Ribossômico/química , Carbono/metabolismo , RNA Ribossômico 16S/genética , Biotransformação , Análise por Conglomerados , China , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Sedimentos Geológicos/microbiologia , Alcaligenes , Poluição Ambiental , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética
16.
Braz J Microbiol ; 48(2): 305-313, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28065387

RESUMO

The aerobic degradation of aromatic compounds by bacteria is performed by dioxygenases. To show some characteristic patterns of the dioxygenase genotype and its degradation specificities, twenty-nine gram-negative bacterial cultures were obtained from sediment contaminated with phenolic compounds in Wuhan, China. The isolates were phylogenetically diverse and belonged to 10 genera. All 29 gram-negative bacteria were able to utilize phenol, m-dihydroxybenzene and 2-hydroxybenzoic acid as the sole carbon sources, and members of the three primary genera Pseudomonas, Acinetobacter and Alcaligenes were able to grow in the presence of multiple monoaromatic compounds. PCR and DNA sequence analysis were used to detect dioxygenase genes coding for catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenase. The results showed that there are 4 genotypes; most strains are either PNP (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is positive) or PNN (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is negative). The strains with two dioxygenase genes can usually grow on many more aromatic compounds than strains with one dioxygenase gene. Degradation experiments using a mixed culture representing four bacterial genotypes resulted in the rapid degradation of phenol. Determinations of substrate utilization and phenol degradation revealed their affiliations through dioxygenase genotype data.


Assuntos
Dioxigenases/genética , Dioxigenases/metabolismo , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/metabolismo , Fenol/metabolismo , Acinetobacter , Alcaligenes , Biotransformação , Carbono/metabolismo , China , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Poluição Ambiental , Sedimentos Geológicos/microbiologia , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Filogenia , Reação em Cadeia da Polimerase , Pseudomonas , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Poluentes do Solo/metabolismo
17.
Environ Sci Technol ; 50(21): 11837-11843, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27689893

RESUMO

A new method using nonthermal plasma to add Cl active sites on activated carbon was proposed to improve the efficiency of activated carbon (AC) for removal of mercury from flue gas. The experiments were conducted via a lab-scale dielectric barrier discharge nonthermal plasma system and a vertical adsorption reactor. The results showed that the nonthermal plasma treatment with a small amount of Cl2 successfully added Cl active sites on AC and greatly increased the mercury removal efficiency of AC by chemisorption in a very short treatment time. The increase in Cl2 concentration for AC treatment promoted the efficiency of AC. The capacity of mercury adsorption positively correlated with the content of Cl2 for AC treatment, which depends on the number of Cl active sites on activated carbon. The treated AC maintained a high mercury removal efficiency within a temperature range of 30-210 °C. SO2 and H2O in flue gas inhibited the removal of mercury by AC, while HCl had a promotional effect. Scanning electron microscopy and X-ray photoelectron spectroscopy analysis indicated the chemisorption of mercury was attributed to the C-Cl groups generated on AC surfaces during Cl2 nonthermal plasma treatment. The C-Cl groups as active sites had strong adsorption energy for mercury, which converted elemental mercury to HgCl2.


Assuntos
Domínio Catalítico , Mercúrio , Adsorção , Carvão Vegetal , Espectroscopia Fotoeletrônica
18.
Wei Sheng Wu Xue Bao ; 56(12): 1901-11, 2016 Dec 04.
Artigo em Chinês | MEDLINE | ID: mdl-29741859

RESUMO

Objective: Lipid transfer protein superfamily is involved in lipid transport and metabolism. This study aimed to construct mutants of three lipid transfer protein encoding genes in Mesorhizobium huakuii 7653R, and to study the phenotypes and function of mutations during symbiosis with Astragalus sinicus. Methods: We used bioinformatics to predict structure characteristics and biological functions of lipid transfer proteins, and conducted semi-quantitative and fluorescent quantitative real-time PCR to analyze the expression levels of target genes in free-living and symbiotic conditions. Using pK19mob insertion mutagenesis to construct mutants, we carried out pot plant experiments to observe symbiotic phenotypes. Results: MCHK-5577, MCHK-2172 and MCHK-2779 genes encoding proteins belonged to START/RHO alpha_C/PITP/Bet_v1/CoxG/CalC (SRPBCC) superfamily, involved in lipid transport or metabolism, and were identical to M. loti at 95% level. Gene relative transcription level of the three genes all increased compared to free-living condition. We obtained three mutants. Compared with wild-type 7653R, above-ground biomass of plants and nodulenitrogenase activity induced by the three mutants significantly decreased. Conclusion: Results indicated that lipid transfer protein encoding genes of Mesorhizobium huakuii 7653R may play important roles in symbiotic nitrogen fixation, and the mutations significantly affected the symbiotic phenotypes. The present work provided a basis to study further symbiotic function mechanism associated with lipid transfer proteins from rhizobia.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Transporte/genética , Mesorhizobium/fisiologia , Simbiose , Astrágalo/microbiologia , Astrágalo/fisiologia , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Clonagem Molecular , Regulação Bacteriana da Expressão Gênica , Mesorhizobium/genética , Mutagênese , Mutação , Fixação de Nitrogênio , Filogenia
19.
Wei Sheng Wu Xue Bao ; 55(7): 843-50, 2015 Jul 04.
Artigo em Chinês | MEDLINE | ID: mdl-26710603

RESUMO

OBJECTIVE: Catalase-peroxidase KatG can protect bacteria from damage of reactive oxygen species. This study investigated the antioxidative function of catalase - peroxidase gene katG in Rhizobium leguminosarum 3841. METHODS: katG mutant strain of R. leguminosarum was constructed by homologous recombination. The wild type, katG mutant and complementary strain were challenged by oxidative stress and symbiotic ability. RESULTS: Under free - living conditions, the katG mutant exhibited no generation time extension. However, cells of the katG strain were deficient in consumption oj high concentrations of H2O2and were vulnerable after aquick exposure to H2O2. The real-time qRT-PCR results showec that katG was expressed independently of exogenous H2O2. In contrast, the katG mutant strain displayed higher expres, level of ohrB gene and lower expression level of grxC than the wild type. With regard to symbiotic capacities with Pisum sativum, the katG mutant was indistinguishable in root nodule nitrogenase activity and competition nodule ability from the wild type. However, katG gene was expressed significantly lower in bacteroids than that in free-living strains. Besides, the colonization of the pea rhizosphere by the katG mutant was impaired compared to that of the wild type. CONCLUSION: ThE deletion of katG had nosignificant effect in 3841 under the free-living and symbiosis condition but was essential ir antioxidation and colonization of the pea rhizosphere. Although katG could not be induced by H2O2, it still played acentra role in antioxidation and symbiotic nitrogen fixation by regulating the antioxidant genes such as ohrB and grxC.


Assuntos
Antioxidantes/metabolismo , Proteínas de Bactérias/metabolismo , Catalase/metabolismo , Rhizobium leguminosarum/enzimologia , Proteínas de Bactérias/genética , Catalase/genética , Peróxido de Hidrogênio/metabolismo , Fixação de Nitrogênio , /fisiologia , Rhizobium leguminosarum/genética , Rhizobium leguminosarum/fisiologia , Nódulos Radiculares de Plantas/microbiologia , Nódulos Radiculares de Plantas/fisiologia , Simbiose
20.
Curr Microbiol ; 71(3): 321-5, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26063444

RESUMO

A Gram-positive, motile, endospore-forming, rod-shaped bacterium, designated RP-207(T), was isolated from the nodules of Robinia pseudoacacia L. plants planted in Enshi District, Hubei, PR China. Phylogenetic analyses based on the 16S rRNA gene sequence showed that the novel strain was affiliated to the genus Paenibacillus, with its closest relatives being Paenibacillus xylanilyticus XIL14(T) (95.6%), Paenibacillus peoriae DSM8320(T) (95.3%) and Paenibacillus polymyxa DSM 36(T) (95.3%). The DNA G+C content was 47.0 mol%. DNA-DNA hybridization value between strain RP-207(T) and P. xylanilyticus XIL14(T) was 40.1%. The diamino acid found in the cell wall peptidoglycan was meso-diaminopimelic. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified amino-phospholipid and an unknown phospholipid. The predominant menaquinone was menaquinone-7 (MK-7), and the major fatty acid was anteiso-C15:0 and C16:0. On the basis of its physiological and biochemical characteristics and the level of DNA-DNA hybridization, strain RP-207(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus enshidis sp. nov. is proposed. The type strain is RP-207(T) (=CCTCC AB 2013275(T) = KCTC 33519(T)).


Assuntos
Paenibacillus/classificação , Paenibacillus/isolamento & purificação , Robinia/microbiologia , Nódulos Radiculares de Plantas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Locomoção , Microscopia Eletrônica de Varredura , Hibridização de Ácido Nucleico , Paenibacillus/genética , Paenibacillus/fisiologia , Peptidoglicano/análise , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos/citologia , Vitamina K 2/análise
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