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1.
Small ; 20(27): e2305779, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38764279

RESUMO

Photocatalytic water splitting for clean hydrogen production has been a very attractive research field for decades. However, the insightful understanding of the actual active sites and their impact on catalytic performance is still ambiguous. Herein, a Pr-doped TiO2-supported Cu single atom (SA) photocatalyst is successfully synthesized (noted as Cu/Pr-TiO2). It is found that Pr dopants passivate the formation of oxygen vacancies, promoting the density of photogenerated electrons on the CuSAs, and optimizing the electronic structure and H* adsorption behavior on the CuSA active sites. The photocatalytic hydrogen evolution rate of the obtained Cu/Pr-TiO2 catalyst reaches 32.88 mmol g-1 h-1, 2.3 times higher than the Cu/TiO2. Innovatively, the excellent catalytic activity and performance is attributed to the active sites change from O atoms to CuSAs after Pr doping is found. This work provides new insight for understanding the accurate roles of single atoms in photocatalytic water splitting.

2.
Ann Rheum Dis ; 83(4): 475-487, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38129117

RESUMO

OBJECTIVES: This phase 2b, randomised, double-blind, placebo-controlled trial evaluated the efficacy and safety of telitacicept, a novel fusion protein that neutralises signals of B lymphocyte stimulator and a proliferation-inducing ligand, in active systemic lupus erythematosus (SLE). METHODS: Adult patients with active SLE (n=249) were recruited from 29 hospitals in China and randomised 1:1:1:1 to receive subcutaneous telitacicept at 80 mg (n=62), 160 mg (n=63), 240 mg (n=62) or placebo (n=62) once weekly in addition to standard therapy. The primary endpoint was the proportion of patients achieving an SLE Responder Index 4 (SRI-4) response at week 48. Missing data were imputed using the last observation carried forward method. RESULTS: At week 48, the proportion of patients achieving an SRI-4 response was 75.8% in the 240 mg telitacicept group, 68.3% in the 160 mg group, 71.0% in the 80 mg group and 33.9% in the placebo group (all p<0.001). Significant treatment responses were observed in secondary endpoints, including a ≥4-point reduction on the Systemic Lupus Erythematosus Disease Activity Index, a lack of Physician's Global Assessment score worsening and a glucocorticoid dose reduction in the 240 mg group. Telitacicept was well tolerated, and the incidence of adverse events and serious adverse events was similar between the telitacicept and placebo groups. CONCLUSIONS: This phase 2b clinical trial met the primary endpoint. All telitacicept groups showed a significantly higher proportion of patients achieving an SRI-4 response than the placebo group at week 48, and all doses were well tolerated. These results support further investigations of telitacicept in clinical trials involving more diverse populations and larger sample sizes. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT02885610).


Assuntos
Lúpus Eritematoso Sistêmico , Proteínas Recombinantes de Fusão , Adulto , Humanos , Método Duplo-Cego , Glucocorticoides/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Índice de Gravidade de Doença , Resultado do Tratamento
3.
BMC Microbiol ; 24(1): 149, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678219

RESUMO

BACKGROUND: Recognition of seasonal trends in bacterial infection and drug resistance rates may enhance diagnosis, direct therapeutic strategies, and inform preventive measures. Limited data exist on the seasonal variability of Acinetobacter baumannii. We investigated the seasonality of A. baumannii, the correlation between temperature and meropenem resistance, and the impact of temperature on this bacterium. RESULTS: Meropenem resistance rates increased with lower temperatures, peaking in winter/colder months. Nonresistant strain detection exhibited temperature-dependent seasonality, rising in summer/warmer months and declining in winter/colder months. In contrast, resistant strains showed no seasonality. Variations in meropenem-resistant and nonresistant bacterial resilience to temperature changes were observed. Nonresistant strains displayed growth advantages at temperatures ≥ 25 °C, whereas meropenem-resistant A. baumannii with ß-lactamase OXA-23 exhibited greater resistance to low-temperature (4 °C) stress. Furthermore, at 4 °C, A. baumannii upregulated carbapenem resistance-related genes (adeJ, oxa-51, and oxa-23) and increased meropenem stress tolerance. CONCLUSIONS: Meropenem resistance rates in A. baumannii display seasonality and are negatively correlated with local temperature, with rates peaking in winter, possibly linked to the differential adaptation of resistant and nonresistant isolates to temperature fluctuations. Furthermore, due to significant resistance rate variations between quarters, compiling monthly or quarterly reports might enhance comprehension of antibiotic resistance trends. Consequently, this could assist in formulating strategies to control and prevent resistance within healthcare facilities.


Assuntos
Acinetobacter baumannii , Antibacterianos , Meropeném , Testes de Sensibilidade Microbiana , Estações do Ano , Temperatura , beta-Lactamases , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Meropeném/farmacologia , Antibacterianos/farmacologia , beta-Lactamases/genética , Adaptação Fisiológica/genética , Farmacorresistência Bacteriana/genética , Humanos , Infecções por Acinetobacter/microbiologia , Proteínas de Bactérias/genética
4.
BMC Infect Dis ; 24(1): 145, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291356

RESUMO

BACKGROUND: Niemann-Pick Disease type C is a fatal autosomal recessive lipid storage disorder caused by NPC1 or NPC2 gene mutations and characterized by progressive, disabling neurological deterioration and hepatosplenomegaly. Herein, we identified a novel compound heterozygous mutations of the NPC1 gene in a Chinese pedigree. CASE PRESENTATION: This paper describes an 11-year-old boy with aggravated walking instability and slurring of speech who presented as Niemann-Pick Disease type C. He had the maternally inherited c.3452 C > T (p. Ala1151Val) mutation and the paternally inherited c.3557G > A (p. Arg1186His) mutation using next-generation sequencing. The c.3452 C > T (p. Ala1151Val) mutation has not previously been reported. CONCLUSIONS: This study predicted that the c.3452 C > T (p. Ala1151Val) mutation is pathogenic. This data enriches the NPC1 gene variation spectrum and provides a basis for familial genetic counseling and prenatal diagnosis.


Assuntos
Doença de Niemann-Pick Tipo C , Criança , Humanos , Masculino , Proteínas de Transporte/genética , Mutação , Proteína C1 de Niemann-Pick/genética , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/genética , Diagnóstico Pré-Natal
5.
Crit Rev Microbiol ; : 1-9, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37452617

RESUMO

Clostridioides difficile is a Gram-positive, spore-forming, rod-shaped, obligate anaerobe that is the leading cause of antibiotic-associated diarrhea. Type IV pili (T4P) are elongated appendages on the surface of C. difficile that are polymerized from many pilin proteins. T4P play an important role in C. difficile adherence and particularly in its persistence in the host intestine. Recent studies have shown that T4P promote C. difficile aggregation, surface motility, and biofilm formation, which may enhance its pathogenicity. Additionally, the second messenger cyclic diguanylate increases pilA1 transcript abundance, indirectly promoting T4P-mediated aggregation, surface motility, and biofilm formation of C. difficile. This review summarizes recent advances in C. difficile T4P research and the physiological activities of T4P in the context of C. difficile pathogenesis.

6.
Org Biomol Chem ; 21(40): 8094-8097, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37789756

RESUMO

A novel organocatalytic one-pot cascade ether oxidation iminium-ion activation strategy for the synthesis of naphtho[2,1-b]furan-1-carbaldehyde and benzofuran-3-carbaldehyde from high atomic utilization transformation of aryl allyl ethers has been developed. Its synthetic application will provide a new ether oxidation iminium-ion activation cascade tool for the efficient synthesis of complex molecules.

7.
Small ; 18(42): e2204056, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36101903

RESUMO

The further applications of liquid metals (LMs) are limited by their common shortcoming of silver-white physical appearance, which deviates from the impose stringent requirements for color and aesthetics. Herein, a concept is proposed for constructing fluorescent core-shell structures based on the components and properties of LMs, and metal halides. The metal halides endow LMs with polychromatic and stable fluorescence characteristics. As a proof-of-concept, LMs-Al obtained by mixing of LMs with aluminum (Al) is reported. The surface of LMs-Al is transformed directly from Al to a multi-phase metal halide of K3 AlCl6 with double perovskites structure, via redox reactions with KCl + HCl solution in a natural environment. The formation of core-shell structure from the K3 AlCl6 and LMs is achieved, and the shell with different phases can emit a cyan light by the superimposition of the polychromatic spectrum. Furthermore, the LMs can be directly converted into a fluorescent shell without affecting their original features. In particular, the luminescence properties of shells can be regulated by the components in LMs. This study provides a new direction for research in spontaneous interfacial modification and fluorescent functionalization of LMs and promises potential applications, such as lighting and displays, anti-counterfeiting measures, sensing, and chameleon robots.


Assuntos
Alumínio , Prata , Prata/química , Fluorescência , Luminescência
8.
J Org Chem ; 87(9): 5464-5471, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35389661

RESUMO

3-Alkyl-3-hydroxyoxindoles, a subclass of oxindole products, have antioxidant, neuroprotective, anticancer, and anti-HIV activities. In this study, a green and economical protocol for the synthesis of 3-alkyl-3-hydroxyoxindoles is developed for the first time via α-alkylation-α-hydroxylation of oxindole with benzyl alcohols without using any transition-metal catalysts in yields of 29-93%.


Assuntos
Álcoois , Alquilação , Hidroxilação , Estrutura Molecular , Oxindóis
9.
Anaerobe ; 75: 102585, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35545183

RESUMO

Clostridioides difficile is a Gram-positive, obligate anaerobic, spore-producing intestinal opportunistic pathogen. CDI outbreaks in Europe and the Americas in recent years are a major health concern. Intestinal short-chain fatty acids (SCFAs) are an important energy source for colonic epithelial cells, and the roles of SCFAs in reducing intestinal inflammation, inhibiting intestinal tumors, and regulating gut microbial homeostasis are being actively researched. Furthermore, SCFAs attenuate CDI or directly inhibit C. difficile growth through different pathways in vivo and in vitro. This review assesses the role of SCFAs in CDI and discusses the potential use of these molecules as therapeutic targets for CDI.


Assuntos
Clostridioides difficile , Infecções por Clostridium , Microbioma Gastrointestinal , Infecções por Clostridium/tratamento farmacológico , Células Epiteliais/metabolismo , Ácidos Graxos Voláteis/metabolismo , Humanos
10.
Anticancer Drugs ; 32(10): 1105-1110, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34232943

RESUMO

Recombinant human interferon-α1b (IFN-α1b) is the first genetic engineered drug of China and is approved for cancer treatment by Chinese Food and Drug Administration. Although recombinant IFN-α1b is biologically and therapeutically active, its long-term efficacy against advanced melanoma is unknown. Ninety patients who were diagnosed with stage IV melanoma and received recombinant IFN-α1b therapy in our department were included in this study. The safety and efficacy of IFN-α1b were analyzed. IFN-α1b was overall well tolerated, with only 7.8% of the patients showing grade 3 toxicity and none with grade 4 toxicity or treatment-related death. The most common adverse effect was fever (78.9%). Furthermore, increasing the drug dosage showed no increase in the incidence of adverse events. The median overall survival (mOS) of the cohort was 14.1 months (95% confidence interval, 11.3-16.9 months). There was no significant difference of the mOS between samples of various primary sites. In the 42 patients who had not received prior adjuvant interferon therapy, the objective response rate, disease control rate and clinical benefit rate were 7.1, 28.5 and 21.4%, respectively. Our findings suggest that systemic IFN-α1b treatment is a relatively safe therapy and could prolong the survival of patients with unresectable metastatic melanoma.


Assuntos
Interferon-alfa/uso terapêutico , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Feminino , Humanos , Interferon-alfa/administração & dosagem , Interferon-alfa/efeitos adversos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Estudos Retrospectivos , Neoplasias Cutâneas/patologia , Análise de Sobrevida , Adulto Jovem
11.
Anaerobe ; 67: 102295, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33246096

RESUMO

OBJECTIVE: Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions. A 1-year follow-up study was performed to determine the incidence, kinetics and influencing factors of C. difficile intestinal colonization. METHODS: Twenty-nine healthy infants (14 girls and 15 boys) living at home with their parents in Handan City were followed by survey from birth to 1 year of age, specifically from October 2014 through December 2015. C. difficile isolates were typed by PCR ribotyping and analyzed for the presence of toxin genes. RESULTS: During the follow-up study period in the first year of life, 20 of the 29 total enrolled infants acquired C. difficile. A total of 437 fecal samples were obtained, and 111 (25.4%) samples contained C. difficile, including 79 (71.2%) toxigenic strains. The toxigenic isolates comprised six PCR ribotypes, and two PCR ribotypes were identified as nontoxigenic strains. CONCLUSION: Our study showed that C. difficile colonization increase with age during the 12-month period, and the dominant toxigenic types of C. difficile isolates in infants were those involved in long-term colonization. Feeding patterns may affect the dynamic progress of C. difficile colonization.


Assuntos
Portador Sadio/epidemiologia , Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecções por Clostridium/epidemiologia , Biodiversidade , China/epidemiologia , Clostridioides difficile/isolamento & purificação , DNA Bacteriano , Fezes/microbiologia , Comportamento Alimentar , Feminino , Seguimentos , Genótipo , Humanos , Incidência , Lactente , Recém-Nascido , Intestinos/microbiologia , Masculino , Reação em Cadeia da Polimerase , RNA Ribossômico 16S , Ribotipagem
12.
BMC Infect Dis ; 19(1): 771, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481053

RESUMO

BACKGROUND: Although worldwide measles elimination achieved great progress for decades, outbreaks were still reported in certain countries. This study describes the epidemiologic features of a substantial measles outbreak in an office building in Beijing and explores control strategies in a crowded city. METHODS: We performed descriptive analyses of data on demographic characteristic, laboratory testing and epidemiological information. RESULTS: From February 25 to March 28, 2016, 43 outbreak-related measles cases occurred in an office building in Beijing. The total crude attack rate was 1.20% in the building. The age range of patients was 23 to 45 years old, of whom 30 (69.8%) were migrants and 5 (11.6%) were vaccinated but without documentation. The attack rate of the department and the company of the source case was 22.73 and 11.86%, respectively. The attack rate in the building was 1.78%, except for the commercial center on the lower floors, which was 0.34%. Of the 43 measles cases, only 19 cases (53.5%) were reported by hospitals through the National Notifiable Disease Reporting System (NNDRS), and the rest were found through active surveillance. Outbreak response immunization was conducted for 6216 persons. CONCLUSIONS: Office buildings in crowded metropolis are prone to large-scale measles outbreaks, and require a rapid outbreak response. Early Outbreak response immunization and active surveillance are important strategies to control outbreaks such as the one reported herein.


Assuntos
Aglomeração , Surtos de Doenças , Sarampo/epidemiologia , Adulto , Pequim/epidemiologia , China/epidemiologia , Surtos de Doenças/prevenção & controle , Feminino , Hospitais , Humanos , Incidência , Masculino , Sarampo/prevenção & controle , Pessoa de Meia-Idade , Urbanização , Vacinação/normas , Vacinação/estatística & dados numéricos , Adulto Jovem
13.
Clin Invest Med ; 42(3): E40-E46, 2019 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-31563159

RESUMO

PURPOSE: To evaluate the diagnostic efficiency of computed tomography (CT) values at the 40~140 keV monochromatic level for the differential diagnosis of solitary pulmonary nodules (SPNs). METHODS: Energy spectrum CT data of 44 patients with SPNs were analyzed retrospectively; 24 patients with malignant SPNs served as the malignant group and 20 patients with benign SPNs served as the benign group. The basic material concentration and the enhancement degree differences in double-phase enhanced scans were compared between the two groups. The sensitivity and specificity were calculated to determine diagnosis, and were compared with the pathology results. RESULTS: The CT values at the 40~90 keV monochromatic level and the iodine concentrations of malignant group were higher than those of benign group in the arterial phase (all P < 0.05). The enhancement degree of the malignant group was higher than that for the benign group in the arterial phase (36.36 ± 33.18 HU vs 16.93 ± 24.17 HU t = 2.243, P = 0.030); however, the enhancement degrees of the two groups were similar in the venous phase (21.99 ± 15.87 HU vs 17.62 ± 24.15 HU t = 0.694, P = 0.493). The area under the curve of the enhancement degree in the arterial phase was 0.792. CONCLUSIONS: Monochromatic imaging and base material concentration of energy spectrum CT can help differentiate between benign and malignant SPNs.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Nódulo Pulmonar Solitário/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
14.
Anaerobe ; 56: 116-123, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30849459

RESUMO

Clostridioides difficile is a colonizer of the human gut; asymptomatic colonization has been reported to be more common in infants and is highly variable across regions even with no symptoms of diarrhea or death. Antibiotic treatment strategies might increase the antibiotic resistance of C. difficile. We performed a one-point study involving 1098 healthy infants (0-36 months) to address the deficiency of reports on C. difficile colonization in Chinese community infants. The C. difficile colonization rate was 22.8% (250/1098), and more than half of the strains (55.2%) were toxigenic isolates. Among the 138 toxigenic isolates, 111 were of the A+B+CDT- genotype, 26 strains were A-B+CDT-, and one strain was A+B+CDT+. Fifteen different PCR ribotypes were found among the 250 isolates, and PCR-ribotype HB03 appeared to be dominant type, accounting for 19.6% (49/250). High levels of resistance to antimicrobial agents were observed. Our study showed that age and hospitalization before stool collection were positively correlated with the C. difficile colonization rate, whereas the delivery term was negatively related to the colonization rate. Particular attention should be paid to the increasing resistance of C. difficile to rifamycin.


Assuntos
Portador Sadio/epidemiologia , Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/epidemiologia , Povo Asiático , Toxinas Bacterianas/genética , Portador Sadio/microbiologia , China/epidemiologia , Infecções por Clostridium/microbiologia , Genótipo , Voluntários Saudáveis , Humanos , Lactente , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Prevalência , Ribotipagem
15.
Int J Mol Sci ; 20(20)2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31614732

RESUMO

The rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the ability for the biosynthesis of long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA) from C18 PUFA precursors, and all the catalytic enzymes including two fatty acyl desaturase 2 (Δ4 Fads2 and Δ6/Δ5 Fads2) and two elongases (Elovl4 and Elovl5) have been identified, providing a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in fish. Stimulatory protein 1 (Sp1) has been speculated to be a vital transcription factor in determining the promoter activity of Fads-like genes in fish, however its regulatory effects on gene expression and LC-PUFA biosynthesis have not been demonstrated. Bioinformatic analysis predicted potential Sp1 binding sites in the promoters of the rabbitfish Δ6/Δ5 fads2 and elovl5, but not in Δ4 fads2 promoter. Here we cloned full-length cDNA of the rabbitfish sp1 gene, which encoded a putative protein of 701 amino acids, and was expressed in all tissues studied with highest levels in gill and eyes. The dual luciferase reporter assay in HepG2 line cells demonstrated the importance of the Sp1 binding site for the promoter activities of both Δ6/Δ5 fads2 and elovl5. Moreover, the electrophoretic mobility shift assay confirmed the direct interaction of Sp1 with the two promoters. Insertion of the Sp1 binding site of Δ6/Δ5 fads2 promoter into the corresponding region of the Δ4 fads2 promoter significantly increased activity of the latter. In the Siganus canaliculatus hepatocyte line (SCHL) cells, mRNA levels of Δ6/Δ5 fads2 and elovl5 were positively correlated with the expression of sp1 when sp1 was overexpressed or knocked-down by RNAi or antagonist (mithramycin) treatment. Moreover, overexpression of sp1 also led to a higher conversion of 18:2n-6 to 18:3n-6, 18:2n-6 to 20:2n-6, and 18:3n-3 to 20:3n-3, which related to the functions of Δ6/Δ5 Fads2 and Elovl5, respectively. These results indicated that Sp1 is involved in the transcriptional regulation of LC-PUFA biosynthesis by directly targeting Δ6/Δ5 fads2 and elovl5 in rabbitfish, which is the first report of Sp1 involvement in the regulation of LC-PUFA biosynthesis in vertebrates.


Assuntos
Ácidos Graxos Dessaturases/genética , Elongases de Ácidos Graxos/genética , Ácidos Graxos Ômega-3/biossíntese , Proteínas de Peixes/genética , Fator de Transcrição Sp1/metabolismo , Animais , Ácidos Graxos Dessaturases/metabolismo , Elongases de Ácidos Graxos/metabolismo , Proteínas de Peixes/metabolismo , Células Hep G2 , Humanos , Fígado/enzimologia , Fígado/metabolismo , Perciformes/genética , Perciformes/metabolismo , Fator de Transcrição Sp1/genética , Regulação para Cima
16.
J Clin Microbiol ; 56(5)2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29467194

RESUMO

Clostridium difficile multilocus sequence type 37 (ST37), which mainly corresponds to ribotype 017, has been a dominant genotype circulating in China. In this study, we report the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to analyze and characterize 204 C. difficile clinical isolates, including 49 ST37 and 155 non-ST37 isolates collected in China and other countries. The distributions of two major protein peaks (m/z 3,242 and 3,286) were significantly different between ST37 and non-ST37 prototype strains and clinical isolates. This difference was reproducible when analysis was performed on different colonies in different runs. This finding was repeated and confirmed by both bioMérieux Vitek MS and Bruker Microflex LT systems on isolates recovered from a variety of geographic regions worldwide. The combination of the two peaks was present in 47 of 49 ST37 isolates, resulting in a sensitivity of 95.9%. In contrast, the peak combination was absent in 153 of 155 non-ST37 isolates, resulting in a specificity of 98.7%. Our results suggest that MALDI-TOF MS is a rapid and reliable tool to identify C. difficile genotype ST37. Work is in progress to characterize the two molecules having peaks at m/z 3,242 and 3,286, which appear to be specific to C. difficile genotype ST37.


Assuntos
Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecções por Clostridium/microbiologia , Tipagem Molecular/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Proteínas de Bactérias/análise , Clostridioides difficile/isolamento & purificação , Análise por Conglomerados , Genótipo , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Phys Chem Chem Phys ; 19(10): 6973-6980, 2017 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-28181601

RESUMO

Metal oxide semiconductors with special structures and morphologies have attracted considerable attention because of their promising applications in gas sensors. In this paper, Ag-LaFeO3 fibers, spheres and cages have been prepared. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), Brunauer-Emmett-Teller (BET) nitrogen adsorption and transmission electron microscopy (TEM) observations, the structure and morphology of the products were characterized. It has been revealed that the as-prepared materials have uniform morphologies and consist of numerous nanocrystals. Sensors based on the Ag-LaFeO3 fibers, spheres and cages all exhibited high responses and good selectivities to formaldehyde gas. Owing to their hollow and porous structure, large surface area and greater number of surface active sites, the Ag-LaFeO3 cages have the lowest operating temperature. The results suggest that the as-prepared Ag-LaFeO3 fibers, spheres and cages, especially the cages, are promising candidates for high performance formaldehyde sensors.

18.
Wei Sheng Yan Jiu ; 46(5): 793-796, 2017 Sep.
Artigo em Zh | MEDLINE | ID: mdl-29903310

RESUMO

OBJECTIVE: To compare the equivalence on detection total coliforms and E. Coli between a new technique with portable sterile culture system and enzyme substrate technique by 51 holes in water. METHODS: Collected drinking water and source water, then detected total coliforms and E. Coli using the twomethod in three laboratories respectively. Analyzed the experimentalresult according to the ISO 17994∶ 2014 which was dedicated to analyze the equivance of water quality between different microbial detection method. RESULTS: The confidence upper limit of the expanded uncertainty of the mean of total coliforms from three laboratories were within the range from 0. 0494 to 0. 0903, andthe range of confidence lower limit were from minus 0. 0713 to minus 0. 0490. The confidence upper limit of the expanded uncertainty of the mean of E. Coli from three laboratories were within the range from 0. 0307 to 0. 0882, while the range of confidence lower limit were from minus 0. 0928 to minus 0. 0381. They were all within the acceptable range which the confidence upper limit was from 0 to 0. 10000, and the confidence lower limit was from minus 0. 10000 to 0. CONCLUSION: The aforementioned method in detecting total coliforms and E. Coli possess the equivalence compared with the classical method, so the portable sterile culture system can be an alternative of method detecting total coliforms and E. Coli in water.


Assuntos
Contagem de Colônia Microbiana/métodos , Água Potável/análise , Enterobacteriaceae/isolamento & purificação , Escherichia coli/isolamento & purificação , Microbiologia da Água , Abastecimento de Água/normas , Técnicas Bacteriológicas/normas , Meios de Cultura , Água Potável/microbiologia , Humanos , Especificidade da Espécie
19.
Anal Chem ; 88(22): 10816-10820, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27797499

RESUMO

γ-Glutamyltranspetidase (GGT) is a cell-membrane-bound enzyme which selectively catalyzes cleavage of the γ-glutamyl bond of glutathione (GSH). It has been identified to be overexpressed in a number of malignant tumor cells. Therefore, fluorescent probes for fast and selective detection of GGT activities are greatly needed. However, the majority of currently available GGT fluorescent probes based on direct conjugation of a γ-glutamyl group to a specific fluorophore generally has slow enzymatic kinetics due to bulky fluorophore too close to the enzyme's active site. Moreover, the uncaged fluorophore with a free amine group might undergo oxidation or other enzymatic transformation and resulted in a complicated time-dependent fluorescence response. Herein, we reported design of a novel fluorescent GGT probe NM-GSH (2), which incorporated a fast intramolecular transcyclization cascade for rapid detection of GGT activities after enzymatic cleavage of the γ-glutamyl group. This design strategy allows introduction of bulky 1,8-naphthalimide fluorophore with improved enzymatic kinetics and lowered detection limit. The transcyclized product 4 gives more than 200-fold fluorescence increment. The probe NM-GSH showed both good selectivity and fast detection of GGT activities with the detection limit as low as 0.21 mU/mL. In addition, the fluorescent product 4 contains no free amine group and is more stable for detection. Most importantly, cell imaging studies showed that the transcyclized product 4 was enriched in lysosomes for selectively lighting up GGT-overexpressed ovarian cancer cells (OVCAR5) but not normal cells (HUVEC), indicating NM-GSH's potentials as an imaging agent in cancer diagnosis and treatment.


Assuntos
Fluorescência , Corantes Fluorescentes/química , gama-Glutamiltransferase/análise , gama-Glutamiltransferase/metabolismo , Linhagem Celular Tumoral , Ciclização , Corantes Fluorescentes/síntese química , Células Endoteliais da Veia Umbilical Humana/enzimologia , Humanos , Microscopia Confocal , Estrutura Molecular
20.
Am J Respir Cell Mol Biol ; 50(2): 398-408, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24053175

RESUMO

Airway hyperresponsiveness (AHR) in asthma is predominantly caused by increased sensitivity of bronchial smooth muscle cells (BSMCs) to stimuli. The sarcoplasmic reticulum (SR)-Ca(2+) release channel, known as ryanodine receptor (RyR), mediates the contractive response of BSMCs to stimuli. FK506-binding protein 12.6 kD (FKBP12.6) stabilizes the RyR2 channel in a closed state. However, the interaction of FKBP12.6 with RyR2 in AHR remains unknown. This study examined the interaction of FKBP12.6 with RyR2 in BSMCs in AHR of asthma. The interaction of FKBP12.6 with RyR2 and FKBP12.6 expression was determined in a rat asthma model and in BSMCs treated with inflammatory cytokines. The calcium responses to contractile agonists were determined in BSMCs with overexpression and knockdown of FKBP12.6. Asthmatic serum, IL-5, IL-13, and TNF-α enhance the calcium response of BSMCs to contractile agonists and cause dissociation of FKBP12.6 from RyR2 and a decrease in FKBP12.6 gene expression in BSMCs in culture and in ovalbumin (OVA)-sensitized and -challenged rats. Knockdown of FKBP12.6 in BSMCs causes a decrease in the association of RyR2 with FKBP12.6 and an increase in the calcium response of BSMCs. Overexpression of FKBP12.6 increases the association of FKBP12.6 with RyR2, decreases the calcium response of BSMCs, and normalizes airway responsiveness in OVA-sensitized and -challenged rats. Dissociation of FKBP12.6 from RyR2 in BSMCs is responsible for the increased calcium response contributing to AHR in asthma. Manipulating the interaction of FKBP12.6 with RyR2 might be a novel and useful treatment for asthma.


Assuntos
Asma/metabolismo , Cálcio/metabolismo , Miócitos de Músculo Liso/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Proteínas de Ligação a Tacrolimo/metabolismo , Animais , Modelos Animais de Doenças , Interleucina-13/metabolismo , Transporte de Íons/fisiologia , Ratos , Ratos Sprague-Dawley , Transtornos Respiratórios/genética , Transtornos Respiratórios/metabolismo , Transtornos Respiratórios/fisiopatologia , Retículo Sarcoplasmático/metabolismo
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