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1.
J Infect Dis ; 225(5): 825-835, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32939551

RESUMO

Previous studies demonstrated that transforming growth factor (TGT) ß1 plays an immunosuppressive role in clinical tuberculosis. However, the contribution of TGF-ß1 gene polymorphisms to human tuberculosis susceptibility remains undetermined. In this study, we showed that single-nucleotide polymorphisms (SNPs) in TGF-ß1 gene were associated with increased susceptibility to tuberculosis in the discovery cohort (1533 case patients and 1445 controls) and the validation cohort (832 case patients and 1084 controls), and 2 SNPs located in the promoter region (rs2317130 and rs4803457) are in strong linkage disequilibrium. The SNP rs2317130 was associated with the severity of tuberculosis. Further investigation demonstrated that rs2317130 CC genotype is associated with higher TGF-ß1 and interleukin 17A production. The mechanistic study showed that rs2317130 C allele affected TGF-ß1 promoter activity by regulating binding activity to nuclear extracts. These findings provide insights into the pathogenic role of TGF-ß1 in human tuberculosis and reveal a function for the TGF-ß1 promoter SNPs in regulating immune responses during Mycobacterium tuberculosis infection.


Assuntos
Fator de Crescimento Transformador beta1 , Tuberculose , Humanos , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Polimorfismo de Nucleotídeo Único , Fator de Crescimento Transformador beta , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Tuberculose/genética
2.
Biochem Biophys Res Commun ; 598: 113-118, 2022 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-35158209

RESUMO

Mycobacterium tuberculosis (Mtb) is an extremely successful intracellular pathogen that cause a large number of death worldwide. It is interesting that this non-phytopathogen can synthesize cytokinin by "lonely guy" (LOG) protein. The cytokinin biosynthesis pathway in Mtb is not clear. Here we determined the crystal structure of LOG from Mtb (MtLOG) at a high resolution of 1.8 Å. MtLOG exists as dimer which belongs to type-I LOG and shows a typical α-ß Rossmann fold. Like other LOGs, MtLOG also contains a conserved "PGGXGTXXE" motif that contributes to the formation of an active site. For the first time, we found that the MtLOG binds to Mg2+ in the negative potential pocket. According to the docking result, we found that Arg78, Arg98 and Tyr162 should be the key amino acid involved in substrate binding. Our findings provide a structural basis for cytokinin study in Mtb and will play an important role in design and development of enzyme inhibitors.


Assuntos
Proteínas de Bactérias/química , Mycobacterium tuberculosis/química , Arginina , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Citocininas/metabolismo , Modelos Moleculares , Mycobacterium tuberculosis/genética , Conformação Proteica , Multimerização Proteica
3.
BMC Microbiol ; 22(1): 249, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253713

RESUMO

BACKGROUND: Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) remains a global health issue. The characterized virulent M. tb H37Rv, avirulent M. tb H37Ra and BCG strains are widely used as reference strains to investigate the mechanism of TB pathogenicity. Here, we attempted to determine metabolomic signatures associated with the Mycobacterial virulence in human macrophages through comparison of metabolite profile in THP-1-derived macrophages following exposure to the M. tb H37Rv, M. tb H37Ra and BCG strains. RESULTS: Our findings revealed remarkably changed metabolites in infected macrophages compared to uninfected macrophages. H37Rv infection specifically induced 247 differentially changed metabolites compared to H37Ra or BCG infection. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed H37Rv specifically induces tryptophan metabolism. Moreover, quantitative PCR (qPCR) results showed that indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2) which converts the tryptophan to a series of biologically second metabolites were up-regulated in H37Rv-infected macrophages compared to H37Ra- or BCG-infected macrophages, confirming the result of enhanced tryptophan metabolism induced by H37Rv infection. These findings indicated that targeting tryptophan (Trp) metabolism may be a potential therapeutic strategy for pulmonary TB. CONCLUSIONS: We identified a number of differentially changed metabolites that specifically induced in H37Rv infected macrophages. These signatures may be associated with the Mycobacterial virulence in human macrophages. The present findings provide a better understanding of the host response associated with the virulence of the Mtb strain.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Vacina BCG , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Macrófagos/microbiologia , Metabolômica , Triptofano/metabolismo , Triptofano Oxigenase/metabolismo , Tuberculose/microbiologia
4.
BMC Med Res Methodol ; 22(1): 89, 2022 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-35369859

RESUMO

BACKGROUND: Rapid Advice Guidelines (RAG) provide decision makers with guidance to respond to public health emergencies by developing evidence-based recommendations in a short period of time with a scientific and standardized approach. However, the experience from the development process of a RAG has so far not been systematically summarized. Therefore, our working group will take the experience of the development of the RAG for children with COVID-19 as an example to systematically explore the methodology, advantages, and challenges in the development of the RAG. We shall propose suggestions and reflections for future research, in order to provide a more detailed reference for future development of RAGs. RESULT: The development of the RAG by a group of 67 researchers from 11 countries took 50 days from the official commencement of the work (January 28, 2020) to submission (March 17, 2020). A total of 21 meetings were held with a total duration of 48 h (average 2.3 h per meeting) and an average of 16.5 participants attending. Only two of the ten recommendations were fully supported by direct evidence for COVID-19, three recommendations were supported by indirect evidence only, and the proportion of COVID-19 studies among the body of evidence in the remaining five recommendations ranged between 10 and 83%. Six of the ten recommendations used COVID-19 preprints as evidence support, and up to 50% of the studies with direct evidence on COVID-19 were preprints. CONCLUSIONS: In order to respond to public health emergencies, the development of RAG also requires a clear and transparent formulation process, usually using a large amount of indirect and non-peer-reviewed evidence to support the formation of recommendations. Strict following of the WHO RAG handbook does not only enhance the transparency and clarity of the guideline, but also can speed up the guideline development process, thereby saving time and labor costs.


Assuntos
COVID-19 , COVID-19/epidemiologia , Criança , Surtos de Doenças , Guias como Assunto , Humanos , Saúde Pública
5.
Eur J Pediatr ; 181(12): 4019-4037, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36109390

RESUMO

Children are the future of the world, but their health and future are facing great uncertainty because of the coronavirus disease 2019 (COVID-19) pandemic. In order to improve the management of children with COVID-19, an international, multidisciplinary panel of experts developed a rapid advice guideline at the beginning of the outbreak of COVID-19 in 2020. After publishing the first version of the rapid advice guideline, the panel has updated the guideline by including additional stakeholders in the panel and a comprehensive search of the latest evidence. All recommendations were supported by systematic reviews and graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Expert judgment was used to develop good practice statements supplementary to the graded evidence-based recommendations. The updated guideline comprises nine recommendations and one good practice statement. It focuses on the key recommendations pertinent to the following issues: identification of prognostic factors for death or pediatric intensive care unit admission; the use of remdesivir, systemic glucocorticoids and antipyretics, intravenous immunoglobulin (IVIG) for multisystem inflammatory syndrome in children, and high-flow oxygen by nasal cannula or non-invasive ventilation for acute hypoxemic respiratory failure; breastfeeding; vaccination; and the management of pediatric mental health. CONCLUSION: This updated evidence-based guideline intends to provide clinicians, pediatricians, patients and other stakeholders with evidence-based recommendations for the prevention and management of COVID-19 in children and adolescents. Larger studies with longer follow-up to determine the effectiveness and safety of systemic glucocorticoids, IVIG, noninvasive ventilation, and the vaccines for COVID-19 in children and adolescents are encouraged. WHAT IS KNOWN: • Several clinical practice guidelines for children with COVID-19 have been developed, but only few of them have been recently updated. • We developed an evidence-based guideline at the beginning of the COVID-19 outbreak and have now updated it based on the results of a comprehensive search of the latest evidence. WHAT IS NEW: • The updated guideline provides key recommendations pertinent to the following issues: identification of prognostic factors for death or pediatric intensive care unit admission; the use of remdesivir, systemic glucocorticoids and antipyretics, intravenous immunoglobulin for multisystem inflammatory syndrome in children, and high-flow oxygen by nasal cannula or non-invasive ventilation for acute hypoxemic respiratory failure; breastfeeding; vaccination; and the management of pediatric mental health.


Assuntos
Antipiréticos , COVID-19 , Insuficiência Respiratória , Adolescente , Criança , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Imunoglobulinas Intravenosas , Oxigênio
6.
Chin J Traumatol ; 25(6): 312-316, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35840469

RESUMO

Transparency Ecosystem for Research and Journals in Medicine (TERM) working group summarized the essential recommendations that should be considered to review and publish a high-quality guideline. These recommendations from editors and reviewers included 10 components of essential requirements: systematic review of existing relevant guidelines, guideline registration, guideline protocol, stakeholders, conflicts of interest, clinical questions, systematic reviews, recommendation consensus, guideline reporting and external review. TERM working group abbreviates them as PAGE (essential requirements for Publishing clinical prActice GuidelinEs), and recommends guideline authors, editors, and peer reviewers to use them for high-quality guidelines.


Assuntos
Guias de Prática Clínica como Assunto , Humanos
7.
J Neuroinflammation ; 18(1): 128, 2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34092247

RESUMO

BACKGROUND: Patients with prior illness are more vulnerable to heat stroke-induced injury, but the underlying mechanism is unknown. Recent studies suggested that NLRP3 inflammasome played an important role in the pathophysiology of heat stroke. METHODS: In this study, we used a classic animal heat stroke model. Prior infection was mimicked by using lipopolysaccharide (LPS) or lipoteichoic acid (LTA) injection before heat stroke (LPS/LTA 1 mg/kg). Mice survival analysis curve and core temperature (TC) elevation curve were produced. NLRP3 inflammasome activation was measured by using real-time PCR and Western blot. Mice hypothalamus was dissected and neuroinflammation level was measured. To further demonstrate the role of NLRP3 inflammasome, Nlrp3 knockout mice were used. In addition, IL-1ß neutralizing antibody was injected to test potential therapeutic effect on heat stroke. RESULTS: Prior infection simulated by LPS/LTA injection resulted in latent inflammation status presented by high levels of cytokines in peripheral serum. However, LPS/LTA failed to cause any change in animal survival rate or body temperature. In the absence of LPS/LTA, heat treatment induced heat stroke and animal death without significant systemic or neuroinflammation. Despite a decreased level of IL-1ß in hypothalamus, Nlrp3 knockout mice demonstrated no survival advantage under mere heat exposure. In animals with prior infection, their heat tolerance was severely impaired and NLRP3 inflammasome induced neuroinflammation was detected. The use of Nlrp3 knockout mice enhanced heat tolerance and alleviated heat stroke-induced death by reducing mice hypothalamus IL-1ß production with prior infection condition. Furthermore, IL-1ß neutralizing antibody injection significantly extended endotoxemic mice survival under heat stroke. CONCLUSIONS: Based on the above results, NLRP3/IL-1ß induced neuroinflammation might be an important mechanistic factor in heat stroke pathology, especially with prior infection. IL-1ß may serve as a biomarker for heat stroke severity and potential therapeutic method.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Golpe de Calor/complicações , Golpe de Calor/fisiopatologia , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doenças Neuroinflamatórias/complicações , Doenças Neuroinflamatórias/metabolismo , Animais , Anticorpos Neutralizantes/uso terapêutico , Modelos Animais de Doenças , Golpe de Calor/tratamento farmacológico , Golpe de Calor/patologia , Inflamassomos/metabolismo , Interleucina-1beta/imunologia , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/deficiência , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Transdução de Sinais , Ácidos Teicoicos , Termotolerância
8.
BMC Cancer ; 21(1): 567, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006241

RESUMO

BACKGROUND: Primary hepatic neuroendocrine tumors (PH-NETs) are extremely rare and unknown. Because of its rarity, its prognosis features and influencing factors are not well established. METHODS: Data of 140 patients with PH-NETs diagnosed in the SEER database from 1975 to 2016 were collected. The demographics and clinic-pathological features were described. By using propensity-score matching (PSM) analysis, three associated cohorts were selected to describe the malignancy of PH-NETs and univariate analysis was conducted. Then, multivariate Cox analyses were performed and a predicting nomograph was constructed. C-index, receiver operating characteristic (ROC) curve and calibration curves were used to evaluate the predictive value of nomogram. RESULTS: The overall survival outcomes of PH-NETs were superior to hepatocellular carcinoma (HCC) with a mean survival time 30.64 vs 25.11 months (p = 0.052), but inferior to gastrointestinal tract neuroendocrine tumors in situ (GI-NETs in situ) with a mean survival time 30.64 vs 41.62 months (p = 0.017). With reference to gastrointestinal neuroendocrine tumors with liver metastasis (GI-NETs-LM), GI-NETs-LM had better outcomes in short time (1-year survival rate: 64.75% vs 56.43%) but was worse in long time (5-year survival rate: 8. 63% vs 18.57%). Multivariate Cox analyses showed that tumor grade and surgery were two independent factors for prognosis of the patients (p < 0.00). Tumor grade and surgery were used to construct the predicting nomogram. The C-index was 0.79 (95%CI = 0.75-0.83). The area under curve (AUC) values in ROC were 0.868 in 1-year and 0.917 in 3-year survival and the calibration curves showed good consistency. CONCLUSIONS: The overall prognosis PH-NETs is generally favorable, better than HCC and GI-NETs-LM in long term. Preoperative biopsy and complete pathological diagnosis were recommended. Radical surgical intervention including transplantation was the first choice in PH-NETs therapy.


Assuntos
Neoplasias Hepáticas/mortalidade , Tumores Neuroendócrinos/mortalidade , Nomogramas , Adulto , Idoso , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Fígado/patologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/patologia , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , Medição de Risco/métodos , Programa de SEER/estatística & dados numéricos , Taxa de Sobrevida , Adulto Jovem
9.
Inorg Chem ; 60(10): 6999-7007, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33938223

RESUMO

A new perovskite oxide semiconductor, CaCu3Fe2Ta2O12, was synthesized through a high-pressure and high-temperature approach. The compound possesses an Im3̅ space group, where it crystallizes to an A-site-ordered but B-site partial ordered quadruple perovskite structure. Spin ordering occurs around 150 K owing to the antiferromagnetic coupling between Fe3+ spins and ferromagnetic coupling between Cu2+ spins. The room-temperature dielectric permittivity of CaCu3Fe2Ta2O12 was measured to be approximately 2500 at 1 kHz. More importantly, isothermal frequency-dielectric spectroscopy demonstrates the existence of two dielectric relaxations. Debye-like relaxation is attributed to charge carriers trapped among the oxygen vacancies at low temperatures and Maxwell-Wagner polarization relaxation at high temperatures. CaCu3Fe2Ta2O12 is a new magnetic semiconductor, where A-site ordering is intercorrelated with second-order Jahn-Teller distortion. These findings offer opportunities to design novel perovskite oxides with attractive magnetic and dielectric properties.

10.
BMC Infect Dis ; 21(1): 1015, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34583653

RESUMO

BACKGROUND: The morbidity of rifampicin/multidrug-resistant tuberculous meningitis (RR/MDR-TBM) has shown an increasing trend globally. Its mortality rate is significantly higher than that of non-rifampicin/multidrug-resistant tuberculous meningitis (NRR/MDR-TBM). This article aimed to explore risk factors related to RR/MDR-TBM, and compare therapeutic effects of linezolid (LZD)- and non-linezolid-containing regimen for RR/MDR-TB patients in Shenzhen city. Furthermore, we aimed to find a better therapy for pathogen-negative TBM with RR/MDR-TBM related risk factors. METHODS: We conducted a retrospective study enrolling 137 hospitalized cases with confirmed TBM from June 2014 to March 2020. All patients were divided into RR/MDR-TBM group (12 cases) and NRR/MDR-TBM group (125 cases) based on GeneXpert MTB/RIF and (or) phenotypic drug susceptibility test results using cerebral spinal fluid (CSF). The risk factors related to RR/MDR-TBM were investigated through comparing clinical and examination features between the two groups. The mortality rate of RR/MDR-TBM patients treated with different regimens was analyzed to compare their respective therapeutic effects. A difference of P < 0.05 was considered statistically significant. RESULTS: Most patients (111/137, 81%) were from southern or southwestern China, and a large proportion (72/137, 52.55%) belonged to migrant workers. 12 cases were RR/MDR-TBM (12/137, 8.8%) while 125 cases were NRR/MDR-TBM (125/137, 91.2%). The proportion of patients having prior TB treatment history in the RR/MDR-TBM group was significantly higher than that of the NRR/MDR-TBM group (6/12 vs. 12/125, 50% vs. 10.5%, P < 0.01). No significant difference was observed on other clinical and examination features between the two groups. Mortality was significantly lower in RR/MDR-TBM patients on linezolid-containing treatment regimen than those who were not (0/7 versus 3/5, 0% versus 60%, P = 0.045). CONCLUSIONS: The main related risk factor of RR/MDR-TBM is the history of anti-tuberculosis treatment. Linezolid-containing regimen appears to lower mortality rate of RR/MDR-TBM significantly in our study. We think Linezolid should be evaluated prospectively in the treatment of RR/MDR-TBM.


Assuntos
Mycobacterium tuberculosis , Tuberculose Meníngea , Tuberculose Resistente a Múltiplos Medicamentos , Antituberculosos/uso terapêutico , China/epidemiologia , Humanos , Linezolida/uso terapêutico , Estudos Retrospectivos , Rifampina/uso terapêutico , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
11.
J Allergy Clin Immunol ; 146(1): 119-127.e4, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32360286

RESUMO

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 was first reported in Wuhan, December 2019, and continuously poses a serious threat to public health, highlighting the urgent need of identifying biomarkers for disease severity and progression. OBJECTIVE: We sought to identify biomarkers for disease severity and progression of COVID-19. METHODS: Forty-eight cytokines in the plasma samples from 50 COVID-19 cases including 11 critically ill, 25 severe, and 14 moderate patients were measured and analyzed in combination with clinical data. RESULTS: Levels of 14 cytokines were found to be significantly elevated in COVID-19 cases and showed different expression profiles in patients with different disease severity. Moreover, expression levels of IFN-γ-induced protein 10, monocyte chemotactic protein-3, hepatocyte growth factor, monokine-induced gamma IFN, and macrophage inflammatory protein 1 alpha, which were shown to be highly associated with disease severity during disease progression, were remarkably higher in critically ill patients, followed by severe and then the moderate patients. Serial detection of the 5 cytokines in 16 cases showed that continuously high levels were associated with deteriorated progression of disease and fatal outcome. Furthermore, IFN-γ-induced protein 10 and monocyte chemotactic protein-3 were excellent predictors for the progression of COVID-19, and the combination of the 2 cytokines showed the biggest area under the curve of the receiver-operating characteristics calculations with a value of 0.99. CONCLUSIONS: In this study, we report biomarkers that are highly associated with disease severity and progression of COVID-19. These findings add to our understanding of the immunopathologic mechanisms of severe acute respiratory syndrome coronavirus 2 infection, and provide potential therapeutic targets and strategies.


Assuntos
Biomarcadores/sangue , Quimiocina CCL7/sangue , Quimiocina CXCL10/sangue , Infecções por Coronavirus/sangue , Pneumonia Viral/sangue , Adulto , Idoso , Betacoronavirus , COVID-19 , Estado Terminal , Citocinas/sangue , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Adulto Jovem
12.
Thorax ; 75(7): 576-583, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32201389

RESUMO

BACKGROUND: Biomarker-based tests for diagnosing TB currently rely on detecting Mycobacterium tuberculosis (Mtb) antigen-specific cellular responses. While this approach can detect Mtb infection, it is not efficient in diagnosing TB, especially for patients who lack aetiological evidence of the disease. METHODS: We prospectively enrolled three cohorts for our study for a total of 630 subjects, including 160 individuals to screen protein biomarkers of TB, 368 individuals to establish and test the predictive model and 102 individuals for biomarker validation. Whole blood cultures were stimulated with pooled Mtb-peptides or mitogen, and 640 proteins within the culture supernatant were analysed simultaneously using an antibody-based array. Sixteen candidate biomarkers of TB identified during screening were then developed into a custom multiplexed antibody array for biomarker validation. RESULTS: A two-round screening strategy identified eight-protein biomarkers of TB: I-TAC, I-309, MIG, Granulysin, FAP, MEP1B, Furin and LYVE-1. The sensitivity and specificity of the eight-protein biosignature in diagnosing TB were determined for the training (n=276), test (n=92) and prediction (n=102) cohorts. The training cohort had a 100% specificity (95% CI 98% to 100%) and 100% sensitivity (95% CI 96% to 100%) using a random forest algorithm approach by cross-validation. In the test cohort, the specificity and sensitivity were 83% (95% CI 71% to 91%) and 76% (95% CI 56% to 90%), respectively. In the prediction cohort, the specificity was 84% (95% CI 74% to 92%) and the sensitivity was 75% (95% CI 57% to 89%). CONCLUSIONS: An eight-protein biosignature to diagnose TB in a high-burden TB clinical setting was identified.


Assuntos
Citocinas/sangue , Programas de Rastreamento/métodos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Adulto , Biomarcadores/sangue , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Curva ROC , Tuberculose/sangue , Tuberculose/microbiologia
13.
Small ; 16(5): e1905328, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31922697

RESUMO

Exploring the origin of transition metal (TM) lattice-doped layered double hydroxides (LDHs) toward the oxygen evolution reaction (OER) plays a crucial role in engineering efficient electrocatalysts. Without understanding the physics behind the TM-induced catalytic enhancements, it would be challenging to design the next generation of electrocatalysts. Herein, single Ru atoms are introduced into a CoCr LDHs lattice to improve activity. In 0.1 m KOH, CoCrRu LDHs require only 290 mV overpotential to drive to 10 mA cm-2 and show a Tafel slope of 56.12 mV dec-1 . Electronic structure analyses based on density functional theory confirm that promoted OER activity originates from synergetic charge transfer among Ru, Cr, and Co elements. Specifically, Ru dopants can downshift d states of Co and enhance electron donation of Cr to oxygenates, which essentially breaks the scaling relation and achieves higher activity. This work provides insights into how single atomic Ru dopant tunes the electronic structures of its neighbor's active site Co and thus increases OER activities.

14.
BMC Pulm Med ; 20(1): 42, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066417

RESUMO

BACKGROUND: Because of its analgesic and light sedative properties, the highly selective alpha-2 adrenergic receptor agonist dexmedetomidine (DEX) has been suggested for the treatment of septic patients, but its effect on the duration of mechanical ventilation remains unclear. The present study was conducted to review the extant literature in DEX and determine its influence on ventilation time in adult septic patients. METHODS: Databases of PubMed, Cochrane, and EMBASE were applied till 20th January 2019 without language restriction. The searching strategy as following: sepsis OR septic AND mechanical ventilation AND dexmedetomidine. Two authors screened titles, abstracts, and even articles to meet the including criterion independently. In addition, references of related articles or reviews were also referred. Data was recorded in a table and analyzed using the software of Review Manager 5.0. RESULTS: Four studies with a total of 349 patients were included. Three trials with 267 patients revealed the effect of DEX on duration of mechanical ventilation, two trials with 264 patients on ventilator-free days and four trials with 334 patients on 28-day mortality. The analyzed results indicated that DEX was not associated with significantly different durations of mechanical ventilation (MD 0.65, 95% CI, - 0.13 to 1.42, P = 0.10). However, there were significant differences in ventilator-free days (MD 3.57, 95% CI, 0.26 to 6.89, P = 0.03) and 28-day mortality (RR 0.61, 95% CI, 0.49 to 0.94, P = 0.02) in the septic patients. CONCLUSION: Administration of DEX for sedation in septic patients was not associated with the duration of mechanical ventilation, but it increased the ventilator-free days and reduced 28-day mortality.


Assuntos
Dexmedetomidina/uso terapêutico , Hipnóticos e Sedativos/uso terapêutico , Respiração Artificial , Sepse/terapia , Humanos , Unidades de Terapia Intensiva , Ensaios Clínicos Controlados Aleatórios como Assunto , Sepse/mortalidade , Resultado do Tratamento , Desmame do Respirador
15.
J Am Chem Soc ; 141(12): 4990-4996, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30835451

RESUMO

The discovery of new inorganic functional materials is of fundamental importance in synthetic and materials science. In the past, the discovering new materials relied on a slow and serendipitous trial-and-error process, especially in the well-studied oxide systems. Here, we presented a strategy to shorten the period of discovery of new complex metal oxide materials by rapid phase identification and structure determination with 3D electron diffraction (ED) techniques, which do not require pure samples or single crystal growth. With such strategy, three new complex metal oxide materials (BiTi0.855Fe1.145O4.93, BiTi4FeO11 and BiTi2FeO7) were discovered in the simple ternary Bi2O3-Fe2O3-TiO2 system. To our best knowledge, it is the first time to discover three new complex metal oxide materials with new structure types in a single study of ternary metal oxide system. The structures of new materials were refined by combining powder X-ray diffraction (PXRD) with powder neutron diffraction (PND). The most striking feature in this system is that BiTi0.855Fe1.145O4.93 presents edge-shared five-coordinated iron/titanium polyhedra. In addition, another new phase BiTi4GaO11, which is isostructural with BiTi4FeO11, can be obtained when replacing Fe in BiTi4FeO11 with Ga. The band structure investigation of BiTi0.855Fe1.145O4.93, BiTi4FeO11, BiTi2FeO7 and BiTi4GaO11 shown that they were semiconductors with band gaps of 1.65, 2.0, 1.9, and 2.8 eV, respectively. Although this study focused on rapid developing of new inorganic functional materials, this method for developing new materials is available to all fields in chemistry and material chemistry where the limiting factors are impurity, submicrometer-sized crystals, etc.

16.
Inorg Chem ; 58(20): 14193-14203, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31584269

RESUMO

Topotactic reduction of the perovskite oxide TbBaCo2O5.5 with CaH2 leads to a new crystalline phase TbBaCo2O4.5, adopting a 2 × 2 × 1 superstructure compared to TbBaCo2O5.5. The structure consists of a corner-shared network of square pyramidal CoO5 and trigonal planar CoO3 units. Magnetic susceptibility and variable temperature neutron diffraction data reveal that TbBaCo2O4.5 adopts a G-type antiferromagnetically ordered structure (TN ∼ 322 K). The ordered moments are consistent with the presence of low-spin Co2+ (S = 1/2) in trigonal-planar coordination and high-spin Co2+ centers in square pyramidal coordination. TbBaCo2O4.5 shows lower conductivity than TbBaCo2O5.5, which is consistent with the p-type conduction behavior. The unique anion vacancy arrangements in TbBaCo2O4.5 further complement the role of A-cations in controlling the oxygen vacancy distribution in LnBaCo2O5+δ series and demonstrate more opportunity to tune the structural and physical properties based on cationic and anionic lattice coupling.

17.
BMC Infect Dis ; 19(1): 55, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30651075

RESUMO

BACKGROUND: Tuberculosis (TB) remains a major public health concern on a global scale, especially in developing nations. So far, no formal guidelines are available for the diagnosis and treatment of tuberculosis pleurisy. The diagnosis of TB is worsened by the immense difficulty in differential determination of tuberculosis pleural effusion (TPE) and malignant pleural effusion (MPE). The purpose of this investigation is to assess the differential diagnostic efficiencies of the pleural IFN-γ release assay (IGRA) and widely-used biochemical parameters in the distinction analysis of TPE and MPE. METHODS: A cohort of 222 patients with pleural effusion was examined, comprising of 143 TPE and 58 MPE patients. The patients were examined with IGRA, and the widely-used biomarkers in the pleural effusion and peripheral blood. RESULTS: Our results show that the TPE patients have significantly higher M. tuberculosis (Mtb) antigen-specific IFN-γ responses to ESAT-6 protein and peptide pool in the blood compared to MPE patients. TPE patients were also shown to have enriched Mtb antigen-specific IFN-γ responses in pleural effusion than in peripheral blood. Among the widely-used biomarkers, the adenosine deaminase (ADA) and carcinoembryonic antigen (CEA) in pleural effusion were better biomarkers with high sensitivity and specificity to discriminate TPE and MPE. In addition, pleural IGRA could not be affected by the pleural adhesion, and the applications of the pleural IGRA together with ADA and CEA provide a promising approach for the TPE and MPE differential identification. CONCLUSIONS: Our study proposes that the integration of pleural IGRA and ADA, CEA detection could add to more effective diagnosis stratagems in the discernment between TPE and MPE.


Assuntos
Biomarcadores/análise , Interferon gama/análise , Derrame Pleural Maligno/diagnóstico , Derrame Pleural/diagnóstico , Tuberculose Pleural/diagnóstico , Adenosina Desaminase/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Antígeno Carcinoembrionário/análise , Criança , Feminino , Humanos , Interferon gama/sangue , Masculino , Pessoa de Meia-Idade , Derrame Pleural/microbiologia , Sensibilidade e Especificidade
18.
Bioorg Med Chem ; 27(4): 644-654, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30642693

RESUMO

Dipeptidyl Peptidase-IV (DPP-4) is a validated therapeutic target for type 2 diabetes. Aiming to interact with both residues Try629 and Lys554 in S2' site, a series of novel uracil derivatives 1a-l and 2a-i incorporating benzoic acid moieties at the N3 position were designed and evaluated for their DPP-4 inhibitory activity. Structure-activity relationships (SAR) study led to the identification of the optimal compound 2b as a potent and selective DPP-4 inhibitor (IC50 = 1.7 nM). Docking study revealed the additional salt bridge formed between the carboxylic acid and primary amine of Lys554 has a key role in the enhancement of the activity. Furthermore, compound 2b exhibited no cytotoxicity in human hepatocyte LO2 cells up to 50 µM. Subsequent in vivo evaluations revealed that the ester of 2b robustly improves the glucose tolerance in normal mice. The overall results have shown that compound 2b has the potential to a safe and efficacious treatment for T2DM.


Assuntos
Benzoatos/uso terapêutico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Hipoglicemiantes/farmacologia , Uracila/análogos & derivados , Uracila/uso terapêutico , Animais , Benzoatos/síntese química , Benzoatos/toxicidade , Domínio Catalítico , Linhagem Celular , Dipeptidil Peptidase 4/química , Inibidores da Dipeptidil Peptidase IV/síntese química , Inibidores da Dipeptidil Peptidase IV/toxicidade , Desenho de Fármacos , Teste de Tolerância a Glucose , Humanos , Hipoglicemiantes/síntese química , Hipoglicemiantes/toxicidade , Masculino , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Uracila/toxicidade
19.
Inorg Chem ; 57(3): 1269-1276, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29363963

RESUMO

Solid solutions Ba1-xLnx(Bi0.20Pb0.80)O3-δ (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; 0.00 ≤ x ≲ 0.15) have been prepared under 850 °C. They all crystallize in space group P1 at room temperature. XPS data indicate that the valences are 5+ and 3+ for bismuth, 4+ and 2+ for lead, and 3+ or 4+ for lanthanide. Some of them are superconductors. The superconductive transition temperature Tczero decreases or remains constant with an increase of Ln in the sample when Ln = La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. However, Tczero first decreases, then increases, and finally decreases when Ln = Ce, Pr, which is due to the corresponding sample changes from hole-doped to electron-doped superconductors with an increase of Ce or Pr in the sample.

20.
Inorg Chem ; 56(6): 3475-3482, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28240880

RESUMO

Copper-doped (Tb0.861Mn0.121)MnO3-δ has been synthesized by the conventional solid state reaction method. X-ray, neutron, and electron diffraction data indicate that they crystallize in Pnma space group at room temperature. Two magnetic orderings are found for this series by neutron diffraction. One is the ICAM (incommensurate canted antiferromagnetic) ordering of Mn with a wave vector qMn = (∼0.283, 0, 0) with a ≈ 5.73 Å, b ≈ 5.31 Å, and c ≈ 7.41 Å, and the other is the CAM (canted antiferromagnetic) ordering of both Tb and Mn in the magnetic space group Pn'a21' with a ≈ 5.73 Å, b ≈ 5.31 Å, and c ≈ 7.41 Å. A dielectric peak around 40 K is found for the samples doped with Cu, which is higher than that for orthorhombic TbMnO3.

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