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1.
Chirality ; 36(6): e23682, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38807280

RESUMO

Obtaining optically pure compounds in an eco-friendly and cost-efficient manner plays an important role in human health and pharmaceutical industry. Racemic separation using multistage stereoselective liquid-liquid extraction has become one of the most practical and effective approach to access homochiral enantiomers. Currently, chiral ionic liquids (CILs) with structural designability have become a promising chiral additive and enable them as adjustable candidates for racemic separation. Herein, a high-effective stereoselective liquid-liquid extraction process composed of imidazolium cations and amino acid-derived anions as the chiral additive was established for racemic 2-cyclohexylmandelic acid (CHMA) separation. We have systematically investigated the choice of organic solvent, concentration of CIL, extraction temperature, and the pH of aqueous phase. For three-stage stereoselective extraction, the maximum enantiomeric excess (e.e.) for CHMA was reached up to 40.6%. Furthermore, the mechanism of steric effect and stereoselective capacity between the CILs and racemic CHMA was discussed and simulated. We envision that the work will facilitate the development of CILs in multistage liquid-liquid extraction and promote the large-scale production of optically pure enantiomers.

2.
Mikrochim Acta ; 191(2): 101, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-38231363

RESUMO

Hyaluronidase (HAase) is an important endoglycosidase involved in numerous physiological and pathological processes, such as apoptosis, senescence, and cancer progression. Simple, convenient, and sensitive detection of HAase is important for clinical diagnosis. Herein, an easy-to-operate multicolor visual sensing strategy was developed for HAase determination. The proposed sensor was composed of an enzyme-responsive hydrogel and a nanochromogenic system (gold nanobipyramids (AuNBPs)). The enzyme-responsive hydrogel, formed by polyethyleneimine-hyaluronic acid (PEI-HA), was specifically hydrolyzed with HAase, leading to the release of platinum nanoparticles (PtNPs). Subsequently, PtNPs catalyzed the mixed system of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 to produce TMB2+ under acidic conditions. Then, TMB2+ effectively etched the AuNBPs and resulted in morphological changes in the AuNBPs, accompanied by a blueshift in the localized surface plasmon resonance peak and vibrant colors. Therefore, HAase can be semiquantitatively determined by directly observing the color change of AuNBPs with the naked eye. On the basis of this, the method has a linear detection range of HAase concentrations between 0.6 and 40 U/mL, with a detection limit of 0.3 U/mL. In addition, our designed multicolor biosensor successfully detected the concentration of HAase in human serum samples. The results showed no obvious difference between this method and enzyme-linked immunosorbent assay, indicating the good accuracy and usability of the suggested method.


Assuntos
Benzidinas , Hialuronoglucosaminidase , Nanopartículas Metálicas , Humanos , Hidrogéis , Peróxido de Hidrogênio , Platina
3.
Ren Fail ; 46(1): 2307959, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38289005

RESUMO

BACKGROUND: Sepsis-associated acute kidney injury (S-AKI) is a critical illness and is often associated with high morbidity and mortality rates. The soluble urokinase-type plasminogen activator receptor (suPAR) is an important immune mediator and is involved in kidney injury. However, its diagnostic value in S-AKI patients remains unclear. Therefore, we assessed the early predictive value of suPAR for S-AKI patients. METHODS: We prospectively enrolled adult patients, immediately after fulfilling the sepsis-3 criteria. Plasma suPAR levels at 0-, 12-, 24-, and 48-h post-sepsis diagnosis were measured. S-AKI development was the primary outcome. S-AKI risk factors were analyzed using logistic regression, and the value of plasma suPAR for early S-AKI diagnosis was assessed using receiver operating characteristic (ROC) curves. RESULTS: Of 179 sepsis patients, 63 (35.2%) developed AKI during hospitalization. At 12-, 24-, and 48-h post-sepsis diagnosis, plasma suPAR levels were significantly higher in patients with S-AKI than in patients without S-AKI (p < 0.05). The plasma suPAR had the highest area under the ROC curve of 0.700 (95% confidence interval (CI), 0.621-0.779) at 24-h post-sepsis diagnosis, at which the best discrimination ability for S-AKI was achieved with suPAR of ≥6.31 ng/mL (sensitivity 61.9% and specificity 71.6%). Logistic regression analysis showed that suPAR at 24-h post-sepsis diagnosis remained an independent S-AKI risk factor after adjusting for mechanical ventilation, blood urea nitrogen, and pH. CONCLUSIONS: The findings suggest that plasma suPAR may be a potential biomarker for early S-AKI diagnosis.


Assuntos
Injúria Renal Aguda , Sepse , Adulto , Humanos , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Sepse/complicações , Sepse/diagnóstico , Biomarcadores , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Estado Terminal , Curva ROC , Prognóstico
4.
J Am Chem Soc ; 144(51): 23614-23621, 2022 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-36530144

RESUMO

We have developed a new concept for reversible peptide stapling that involves macrocyclization between two amino groups and decyclization promoted via dual 1,4-elimination. Depending on the trigger moiety, this strategy could be employed to selectively deliver peptides to either intracellular or extracellular targets. As a proof of concept, a peptide inhibitor targeting a lysine-specific demethylase 1 (LSD1) was temporarily cyclized to enhance its stability and ability to cross the cell membrane. Once inside the cells, the biologically active linear peptide was released under reducing environment. Moreover, we have developed reversibly stapled peptides using antimicrobial peptides (RStAMPs) whose bioactive helical conformation can be temporarily destabilized by stapling the peptide backbone. The resulting helix-distorted RStAMPs are nontoxic and highly resistant to protease hydrolysis, while at the infection site, RStAMPs can be rapidly activated by the overproduced H2O2 through the dual 1,4-elimination. The latter restored the helical structure of the native peptide and its antimicrobial activity. This work illustrates a highly valuable macrocyclization strategy for the peptide community and should greatly benefit the field of peptide delivery.


Assuntos
Peróxido de Hidrogênio , Peptídeos , Peptídeos/farmacologia , Peptídeos/química , Conformação Molecular
5.
Analyst ; 147(7): 1492-1498, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35289815

RESUMO

Hydrogen sulfide (H2S) is an active physiological molecule, and its intracellular level has great significance to life functions. In this study, an effective and sensitive method was developed for H2S sensing with dark field microscopy (DFM). The proposed method employed AuNPs as the signal source, DFM as the readout system, and an intelligence algorithm as the image processing and output systems, respectively. The AuNP surface was modified with azido and alkynyl in advance, and then added into a tube cap. As the H2S evaporated from the solution and selectively reduced azido to amino, the click chemistry reaction was inhibited, which resulted in the AuNPs being well dispersed in the solution; otherwise, AuNP aggregation occurred. The scattering colour of single AuNPs could be easily distinguished from that of AuNP aggregations with DFM, and the number or ratio of single AuNPs could also be easily obtained by the custom algorithm. The results showed that the H2S content could be linearly analyzed in a range from 2-80 µM. Furthermore, the proposed sensing strategy has been applied for H2S detection in cell lysate. Compared with the traditional colorimetric method, the results showed no significant difference, indicating the good prospects of the algorithm and proposed H2S sensing method.


Assuntos
Sulfeto de Hidrogênio , Nanopartículas Metálicas , Algoritmos , Ouro/química , Nanopartículas Metálicas/química , Microscopia/métodos
6.
Can J Microbiol ; 68(3): 165-176, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34644507

RESUMO

Brucella abortus is a gram-negative intracellular parasite bacteria that causes serious health hazards in humans and animals. The type IV secretion system (T4SS), encoded by the virB promoter, has been identified as an important virulence factor for Brucella abortus, but its impact on Brucella abortus A19 remains unclear. In this study, the T4SS of Brucella abortus A19 was inactivated by deletion of the virB promoter, resulting in a mutant strain A19ΔvirB. Real-time PCR and western blotting analysis demonstrated that T4SS-related proteins were not expressed after virB promoter deletion. Moreover, the survival rate of A19 in high-salt and strong acidic environments decreased after virB promoter deletion. Compared to the parental strain A19, the A19ΔvirB mutant strain showed reduced growth rate in TSB, decreased invasion ability to macrophages and dendritic cells, and reduced virulence of the mutant strain in macrophages, dendritic cells, and mice. In addition, the A19ΔvirB mutant strain showed enhanced autophagy in macrophages and dendritic cells compared with A19, and the A19ΔvirB mutant strain was able to upregulate IL-6 and downregulate IL-10 in macrophages. These data help us to better understand the T4SS of the A19 vaccine strain and contribute to our efforts to improve Brucella vaccines.


Assuntos
Autofagia , Vacina contra Brucelose , Brucella abortus , Regiões Promotoras Genéticas , Sistemas de Secreção Tipo IV , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Brucella abortus/genética , Brucella abortus/patogenicidade , Camundongos , Sistemas de Secreção Tipo IV/genética , Sistemas de Secreção Tipo IV/metabolismo , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
7.
Nanotechnology ; 32(27)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33765671

RESUMO

Lithium-sulfur batteries (LSBs) have gained intense research enthusiasm due to their high energy density. Nevertheless, the 'shuttle effect' of soluble polysulfide (a discharge product) reduces their cycling stability and capacity, thus restricting their practical application. To tackle this challenging issue, we herein report a sulfonated covalent organic framework modified separator (SCOF-Celgard) that alleviates the shuttling of polysulfide anions and accelerates the migration of Li+ions. Specifically, the negatively charged sulfonate can inhibit the same charged polysulfide anion through electrostatic repulsion, thereby improving the cycle stability of the battery and preventing the Li-anode from being corroded. Meanwhile, the sulfonate groups may facilitate the positively charged lithium ions to pass through the separator. Consequently, the battery assembled with the SCOF-Celgard separator exhibits an 81.1% capacity retention after 120 cycles at 0.5 C, which is far superior to that (55.7%) of the battery with a Celgard separator. It has a low capacity degradation of 0.067% per cycle after 600 cycles at 1 C, and a high discharge capacity (576 mAh g-1) even at 2 C. Our work proves that the modification of a separator with a SCOF is a viable and effective route for enhancing the electrochemical performance of a LSB.

8.
BMC Infect Dis ; 21(1): 460, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016047

RESUMO

BACKGROUND: This case report describes the clinical process of a shepherd who suffered brucellosis-related endocarditis (BE) and spondylitis (BS) and was infected with Brucella melitensis biovar 3 (B. melitensis biovar 3). CASE PRESENTATION: A 55-year-old male patient was admitted to The First Affiliated Hospital of Shihezi University on October 11, 2018, due to over 3 months of intermittent fever, back pain, and heart trouble. The Rose Bengal Plate test was positive, the standard agglutination test titer for brucellosis was 1/800, and the blood culture was positive for B. melitensis biovar 3. Three instances of transthoracic echocardiography examination at days 1, 25, and 376 after admission to the hospital and magnetic resonance imaging (MRI) and computed tomography (CT) checks at days 5 and 38 revealed that the size of the vegetation on the posterior leaflet of the mitral valve increased from 0.7 × 1.4 cm to 1.2 × 1.5 cm and that the left atrium and ventricle were enlarged. The MRI and CT results showed hyperplasia of the second and third vertebra, a cold abscess formed on both sides of the psoas major muscles, and the vertebra hyperplasia became aggravated at a later time point. The patient's situation deteriorated, and heart failure was discovered on October 22, 2019. At the moment of submission of this manuscript, the patient remains in bed at home because of severe debility caused by brucellosis. CONCLUSIONS: This is the first reported case of endocarditis combined with spondylitis caused by B. melitensis biovar 3 in a shepherd. Brucellosis infection can cause work-power losses because of misdiagnosis or a lack of proper treatment. Early diagnosis and treatment are essential for a successful outcome.


Assuntos
Brucella melitensis , Brucelose/microbiologia , Endocardite Bacteriana/microbiologia , Espondilite/microbiologia , Testes de Aglutinação , Brucelose/diagnóstico , Brucelose/patologia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/microbiologia , Valva Mitral/patologia , Espondilite/diagnóstico
9.
Ecotoxicol Environ Saf ; 209: 111796, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33341697

RESUMO

Cerium Ce(III) is one of the major pollutants contained in wastewater generated during Ce(III) mining. However, the effect(s) of Ce(III) on the functional genera responsible for removing nitrogen biologically from wastewater has not been studied and reported. In this study, the effects of Ce(III) on aspects of partial-nitritation-(PN) process including ammonia oxidation rate (AOR), process kinetics, and microbial activities were investigated. It was found that the effect of dosing Ce(III) in the PN system correlated strongly with the AOR. Compared to the control, batch assays dosed with 5 mg/L Ce(III) showed elevated PN efficiency of about 121%, an indication that maximum biological response was feasible upon Ce(III) dose. It was also found that, PN performance was not adversely affected, given that Ce(III) dose was ≤20 mg/L. Process kinetics investigated also suggested that the maximum Ce(III) dose without any visible inhibition to the activities of ammonium oxidizing bacteria was 1.37 mg/L, but demonstrated otherwise when Ce(III) dose exceeded 5.63 mg/L. Compared to the control, microbes conducted efficient Ce(III) removal (averaged 98.66%) via biosorption using extracellular polymeric substances (EPS). Notably, significant deposits of Ce(III) was found within the EPS produced as revealed by SEM, EDX, CLSM and FTIR. 2-dimensional correlation infrared-(2DCOS-IR) revealed ester group (uronic acid) as a major organic functional group that promoted Ce(III) removal. Excitation-emission matrix-(EEM) spectrum and 2DCOS-IR suggested the dominance of Fulvic acid, hypothesized to have promoted the performance of the PN process under Ce(III) dosage.


Assuntos
Cério/toxicidade , Nitrificação/efeitos dos fármacos , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Compostos de Amônio , Bactérias , Reatores Biológicos/microbiologia , Mineração , Nitrogênio , Oxirredução , Esgotos , Águas Residuárias/microbiologia
10.
Arch Virol ; 165(11): 2453-2459, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32767108

RESUMO

Canine parvovirus type 2 (CPV-2) is currently circulating in domestic and wild animals, but our knowledge about CPV-2 infections in raccoon dogs is limited. In this study, VP2 gene sequences of CPV-2 were amplified from rectal swabs of 14 diarrhetic raccoon dogs (Nyctereutes procyonoides) in Hebei province, China, in 2016 and 2017. Phylogenetic analysis of the VP2 gene sequences revealed that most of these sequences (11 of 14) belonged to the same subclade as raccoon dog strain CPV-2/Raccoon_Dog/China/DP-1/16 isolated from Shandong province in 2016. A comparison of deduced amino acid sequences revealed presence of the substitutions S297A and S27T in 11 of those 14 sequences. I418T was observed in a minority of the sequences (4 of 14). In addition, A300D and T301I, P13S and I219V, and N419K were found in three of the sequences. This study shows that CPV-2 strains with different substitutions in their VP2 amino acid sequences were spreading among raccoon dogs in Hebei during 2016 and 2017 and suggests that further studies are needed to monitor the distribution of these strains in China.


Assuntos
Infecções por Parvoviridae/veterinária , Parvovirus Canino/classificação , Cães Guaxinins/virologia , Sequência de Aminoácidos , Animais , Proteínas do Capsídeo/genética , China/epidemiologia , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus Canino/isolamento & purificação
11.
Can J Microbiol ; 66(5): 351-358, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32040345

RESUMO

Iron is a fundamental element required by most organisms, including Brucella. Several researchers have suggested that the iron response regulator (irr) and rhizobial iron regulator (rirA) genes regulate iron acquisition by Brucella abortus, influencing heme synthesis by and virulence of this pathogen. However, little is known about another Brucella species, Brucella melitensis. In this research, we successfully constructed two mutants: M5-90Δirr and M5-90ΔrirA. The adhesion, invasion, and intracellular survivability of these two mutants were evaluated in RAW264.7 cells infected with 1 × 106 CFU of M5-90Δirr, M5-90ΔrirA, or M5-90. We also tested the sensitivity of cells to hydrogen peroxide and their ability to grow. In addition, the virulence of these two mutants was evaluated in BALB/c mice. The results showed that the ability of these two mutants to invade and adhere inside the murine macrophages RAW264.7 was attenuated but their ability to replicate intracellularly was strengthened, enhancing the resistance to hydrogen peroxide. The M5-90Δirr mutant showed stronger growth ability than the parental strain under iron-limiting conditions. No differences were observed in the number of bacteria in spleen between M5-90 and M5-90Δirr at 7 or 15 days postinfection. However, the number of M5-90ΔrirA in spleen reduced significantly at 15 days postinfection. The splenic index of the M5-90Δirr group is evidently lower than that of M5-90. This is the first report that irr and rirA genes of B. melitensis are associated not only with virulence but also with growth ability. Together, our data suggest that M5-90Δirr is a promising Brucella vaccine candidate.


Assuntos
Proteínas de Bactérias/genética , Brucella melitensis/genética , Brucella melitensis/patogenicidade , Regulação Bacteriana da Expressão Gênica/fisiologia , Ferro/metabolismo , Fatores de Transcrição/genética , Animais , Anti-Infecciosos Locais/toxicidade , Western Blotting , Vacina contra Brucelose/imunologia , Brucelose/prevenção & controle , Contagem de Colônia Microbiana , Feminino , Peróxido de Hidrogênio/toxicidade , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Baço/microbiologia , Virulência/genética
12.
Emerg Infect Dis ; 25(8): 1539-1542, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31310219

RESUMO

We isolated Japanese encephalitis virus (JEV) from brain samples of 2 seals with lethal encephalitis at Weihai Aquarium, Weihai, China, in 2017. We confirmed our findings by immunohistochemical staining and electron microscopy. Phylogenetic analysis showed this virus was genotype I. Our findings suggest that JEV might disseminate though infected zoo animals.


Assuntos
Doenças dos Animais/epidemiologia , Doenças dos Animais/virologia , Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa/veterinária , Focas Verdadeiras/virologia , Doenças dos Animais/história , Animais , China/epidemiologia , Vírus da Encefalite Japonesa (Espécie)/classificação , Vírus da Encefalite Japonesa (Espécie)/genética , Vírus da Encefalite Japonesa (Espécie)/ultraestrutura , Feminino , Genes Virais , História do Século XXI , Masculino , Filogenia
13.
Inorg Chem ; 58(24): 16574-16580, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31774657

RESUMO

MOF-253 (Al(OH)(dcbpy), dcbpy = 2,2'-bipyridine-5,5'-dicarboxylic acid) obtained via a microwave-assisted synthesis was used for the construction of a supported Ru complex containing dcbpy (MOF-253-Ru(dcbpy)2) by coordinating its open N,N'-chelating sites with Ru(II) in Ru(dcbpy)2Cl2. The as-obtained MOF-253-Ru(dcbpy)2 acts as a bifunctional photocatalyst for simultaneous CO2 reduction to produce formic acid and CO, as well as semidehydrogenation of 1,2,3,4-tetrahydroisoquinoline (THIQ) to obtain 3,4-dihydroisoquinoline (DHIQ). The performance over the surface-supported MOF-253-Ru(dcbpy)2 is superior to that over Ru-doped MOF-253 (Ru-MOF-253) obtained via a mix-and-match strategy, indicating that the use of open coordination sites in the MOFs for direct construction of a surface-supported complex is a superior strategy to obtain an MOF-supported homogeneous complex. This study shows the possibility of using an MOF as a platform for the construction of multifunctional heterogeneous photocatalytic systems. The coupling of photocatalytic CO2 reduction with the highly selective dehydrogenation of organics provides an economical and green strategy in photocatalytic CO2 reduction and production of valuable organics simultaneously.

14.
Nano Lett ; 18(10): 6271-6278, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30216078

RESUMO

Metal halide perovskite thin films have achieved remarkable performance in optoelectronic devices but suffer from spatial heterogeneity in their electronic properties. To achieve higher device performance and reliability needed for widespread commercial deployment, spatial heterogeneity of optoelectronic properties in the perovskite thin film needs to be understood and controlled. Clear identification of the causes underlying this heterogeneity, most importantly the spatial heterogeneity in charge trapping behavior, has remained elusive. Here, a multimodal imaging approach consisting of photoluminescence, optical transmission, and atomic force microscopy is utilized to separate electronic heterogeneity from morphology variations in perovskite thin films. By comparing the degree of heterogeneity in highly oriented and randomly oriented polycrystalline perovskite thin film samples, we reveal that disorders in the crystallographic orientation of the grains play a dominant role in determining charge trapping and electronic heterogeneity. This work also demonstrates a polycrystalline thin film with uniform charge trapping behavior by minimizing crystallographic orientation disorder. These results suggest that single crystals may not be required for perovskite thin film based optoelectronic devices to reach their full potential.

15.
Water Sci Technol ; 80(12): 2250-2259, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32245917

RESUMO

Aerofloats, such as aniline aerofloat ((C6H5NH)2PSSH), are extensively employed for collection activities in wastewater particularly in cases where minerals are in flotation. Although this aniline aerofloat has efficient collection properties, they are ordinarily biologically persistent chemicals in which case their residual, as well as their byproducts, pose great environmental risks to water and soils. In this study, the removal efficiency of aniline aerofloat (AAF) by a combined vacuum ultraviolet (VUV) and ozone (O3) process (VUV/O3) was evaluated. Furthermore, the impacts of pH, O3, the concentration of AAF and coexisting ions (SiO3 2-, CO3 2-, Cl- (Na+), SO4 2-, Ca2+) were systematically studied. The experiments revealed that, with an initial AAF of 15 mg/L, AAF removal >88% was feasible with a reaction time of 60 min, pH of 8 and O3 of 6 g/h. The order of influence of the selected coexisting ions on the degradation of AAF by VUV/O3 was Ca2+ > CO3 2- > SiO3 2- > Cl- (Na+) >SO4 2-. Compared with VUV and O3 in terms of pollutant degradation rate, VUV/O3 showed a remarkable performance, followed by O3 and VUV. Additionally, the degradation kinetics of AAF by the VUV/O3 process agreed well with first-order elimination kinetics.


Assuntos
Poluentes Ambientais , Ozônio , Poluentes Químicos da Água , Compostos de Anilina , Oxirredução , Raios Ultravioleta , Vácuo , Águas Residuárias
16.
J Am Chem Soc ; 140(5): 1674-1685, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29320850

RESUMO

A series of f-block chromates, CsM(CrO4)2 (M = La, Pr, Nd, Sm, Eu; Am), were prepared revealing notable differences between the AmIII derivatives and their lanthanide analogs. While all compounds form similar layered structures, the americium compound exhibits polymorphism and adopts both a structure isomorphous with the early lanthanides as well as one that possesses lower symmetry. Both polymorphs are dark red and possess band gaps that are smaller than the LnIII compounds. In order to probe the origin of these differences, the electronic structure of α-CsSm(CrO4)2, α-CsEu(CrO4)2, and α-CsAm(CrO4)2 were studied using both a molecular cluster approach featuring hybrid density functional theory and QTAIM analysis and by the periodic LDA+GA and LDA+DMFT methods. Notably, the covalent contributions to bonding by the f orbitals were found to be more than twice as large in the AmIII chromate than in the SmIII and EuIII compounds, and even larger in magnitude than the Am-5f spin-orbit splitting in this system. Our analysis indicates also that the Am-O covalency in α-CsAm(CrO4)2 is driven by the degeneracy of the 5f and 2p orbitals, and not by orbital overlap.

17.
Inorg Chem ; 57(14): 8276-8286, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-29965734

RESUMO

Using the open N,N'-chelating sites of MOF-253 (Al(OH)(dcbpy), dcbpy = 2,2'-bipyridine-5,5'-dicarboxylic acid) to coordinate with Re(I), a linker anchored Re complex MOF-253-Re(CO)3Cl active for photocatalytic CO2 reduction was obtained. Unlike the homogeneous bipyridine containing Re complexes which produce CO during photocatalytic CO2 reduction, formate was obtained as the main CO2 reduction product over the as-obtained MOF-253-Re(CO)3Cl. The linker anchored MOF-253-Re(CO)3Cl showed superior photocatalytic performance compared to its homogeneous counterpart since the usual formation of the bimolecular Re intermediate leading to the deactivation of the homogeneous Re complex was significantly inhibited in the MOF supported Re complex. To enhance its light absorption, a linker anchored Ru sensitizer was simultaneously constructed in MOF-253-Re(CO)3Cl (Ru-MOF-253-Re). The total TON (TON is defined as mole of the evolved H2, CO, and HCOO- over per amount of Rhenium) for CO2 reduction (28.8 in 4 h) over the as-obtained Ru-MOF-253-Re system is comparable or even superior to most already reported Re carbonyl complexes featuring bpy ligands and the Ru-Re bimetallic supramolecular systems constructed via the covalent bond under similar reaction conditions. The enhanced photocatalytic CO2 reduction over the Ru-MOF-253-Re can be ascribed to the improved visible light absorption and the existence of an efficient photoinduced charge transfer from Ru sensitizer to Re catalytic center, as evidenced from the transient absorption studies. The use of MOF-253 as a metalloligand and support to assemble the Ru-Re system as well as a mediator to promote the charge transfer from Ru sensitizer to Re catalytic center resembles the construction of Ru-Re supramolecular structures using covalent bonds, but is more facile in preparation and provides more flexibility. This study demonstrates the possibility of using MOFs with open coordination sites as a platform for the construction of a stable multifunctional hybrid system for artificial photosynthesis.

18.
Arch Virol ; 163(8): 2133-2138, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29675651

RESUMO

The aim of this study was to establish a multiplex PCR (mPCR) method that can simultaneously detect canine parvovirus (CPV-2), canine coronavirus (CCoV) and canine adenovirus (CAV), thereby eliminating the need to detect these pathogens individually. Based on conserved regions in the genomes of these three viruses, the VP2 gene of CPV-2, the endoribonuclease nsp15 gene of CCoV, and the 52K gene of CAV were selected for primer design. The specificity of the mPCR results showed no amplification of canine distemper virus (CDV), canine parainfluenza virus (CPIV), or pseudorabies virus (PRV), indicating that the method had good specificity. A sensitivity test showed that the detection limit of the mPCR method was 1 × 104 viral copies. A total of 63 rectal swabs from dogs with diarrheal symptoms were evaluated using mPCR and routine PCR. The ratio of positive samples to total samples for CPV-2, CCoV, and CAV was 55.6% (35/63) for mPCR and 55.6% (35/63) for routine PCR. Thirty-five positive samples were detected by both methods, for a coincidence ratio of 100%. This mPCR method can simultaneously detect CCoV (CCoV-II), CAV (CAV-1, CAV-2) and CPV-2 (CPV-2a, CPV-2b, CPV-2c), which are associated with viral enteritis, thereby providing an efficient, inexpensive, specific, and accurate new tool for clinical diagnosis and laboratory epidemiological investigations.


Assuntos
Adenovirus Caninos/isolamento & purificação , Coronavirus Canino/isolamento & purificação , Diarreia/veterinária , Doenças do Cão/virologia , Parvovirus Canino/isolamento & purificação , Adenovirus Caninos/classificação , Adenovirus Caninos/genética , Adenovirus Caninos/fisiologia , Animais , Coronavirus Canino/classificação , Coronavirus Canino/genética , Coronavirus Canino/fisiologia , Diarreia/diagnóstico , Diarreia/virologia , Doenças do Cão/diagnóstico , Cães , Parvovirus Canino/classificação , Parvovirus Canino/genética , Parvovirus Canino/fisiologia , Sensibilidade e Especificidade
19.
Arch Virol ; 163(10): 2877-2881, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29987379

RESUMO

Getah virus (GETV), a mosquito-borne virus that mainly infects horses and pigs, has emerged and spread in China. We developed a highly specific and reproducible TaqMan probe-based quantitative reverse transcription PCR (RT-qPCR) assay targeting the non-structural protein 1 of GETV, whose detection limit is 25.5 copies/µL, which is 100-fold higher than that of conventional RT-PCR. RT-qPCR was used to detect GETV RNA in mosquito and animal clinical samples, showing that the accuracy of RT-qPCR was higher than that of conventional RT-PCR. The newly developed RT-qPCR assay may be a useful alternative tool for rapid, simple and specific diagnosis of GETV infection.


Assuntos
Alphavirus/genética , Culex/virologia , Sondas de DNA/genética , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas não Estruturais Virais/genética , Alphavirus/isolamento & purificação , Animais , Sequência de Bases , China , Cavalos , Sus scrofa
20.
Phys Rev Lett ; 118(12): 126401, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28388205

RESUMO

We derive an exact operatorial reformulation of the rotational invariant slave boson method, and we apply it to describe the orbital differentiation in strongly correlated electron systems starting from first principles. The approach enables us to treat strong electron correlations, spin-orbit coupling, and crystal field splittings on the same footing by exploiting the gauge invariance of the mean-field equations. We apply our theory to the archetypical nuclear fuel UO_{2} and show that the ground state of this system displays a pronounced orbital differentiation within the 5f manifold, with Mott-localized Γ_{8} and extended Γ_{7} electrons.

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