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1.
J Am Chem Soc ; 146(15): 10357-10366, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38574191

RESUMO

Electrochemical reduction of carbon dioxide to organic chemicals provides a value-added route for mitigating greenhouse gas emissions. We report a family of carbon-supported Sn electrocatalysts with the tin size varying from single atom, ultrasmall clusters to nanocrystallites. High single-product Faradaic efficiency (FE) and low onset potential of CO2 conversion to acetate (FE = 90% @ -0.6 V), ethanol (FE = 92% @ -0.4 V), and formate (FE = 91% @ -0.6 V) were achieved over the catalysts of different active site dimensions. The CO2 conversion mechanism behind these highly selective, size-modulated p-block element catalysts was elucidated by structural characterization and computational modeling, together with kinetic isotope effect investigation.

2.
Ren Fail ; 46(1): 2308701, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38345059

RESUMO

OBJECTIVE: To explore independent influencing factors for clinical efficacy of roxadustat in hemodialysis patients. METHODS: Hemodialysis patients treated with roxadustat were enrolled. The plasma trough concentrations of roxadustat were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A multiple logistic regression model was established to determine the factors that affect clinical efficacy of roxadustat in patients undergoing hemodialysis. RESULTS: A total of 67 hemodialysis patients were enrolled in the study. The results showed that age, blood trough concentration of roxadustat, and baseline hemoglobin (Hb) level were independent factors of clinical efficacy of roxadustat (OR = 1.06, p = .025 for age; OR = 1.001, p = .037 for plasma concentration; and OR = 0.941, p = .003 for baseline Hb), with an AUC score of 0.859. CONCLUSIONS: Age, blood trough concentration of roxadustat, and baseline Hb level were independent influencing factors of the response to roxadustat in hemodialysis patients.


Assuntos
Insuficiência Renal Crônica , Espectrometria de Massas em Tandem , Humanos , Cromatografia Líquida , Resultado do Tratamento , Glicina/uso terapêutico , Diálise Renal
3.
J Am Chem Soc ; 145(8): 4736-4745, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36790398

RESUMO

While trinuclear [FexM3-x(µ3-O)] cluster-based metal-organic frameworks (MOFs) have found wide applications in gas storage and catalysis, it is still challenging to identify the structure of open metal sites obtained through proper activations and understand their influence on the adsorption and catalytic properties. Herein, we use in situ variable-temperature single-crystal X-ray diffraction to monitor the structural evolution of [FexM3-x(µ3-O)]-based MOFs (PCN-250, M = Ni2+, Co2+, Zn2+, Mg2+) upon thermal activation and provide the snapshots of metal sites at different temperatures. The exposure of open Fe3+ sites was observed along with the transformation of Fe3+ coordination geometries from octahedron to square pyramid. Furthermore, the effect of divalent metals in heterometallic PCN-250 was studied for the purpose of reducing the activation temperature and increasing the number of open metal sites. The metal site structures were corroborated by X-ray absorption and infrared spectroscopy. These results will not only guide the pretreatment of [FexM3-x(µ3-O)]-based MOFs but also corroborate spectral and computational studies on these materials.

4.
Toxicol Appl Pharmacol ; 470: 116549, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37164296

RESUMO

Helicobacter pylori (H. pylori) is an obligate microaerobion and does not survive in low oxygen. Sodium sulfite (SS) reacts and consume oxygen in solutions. The present study aimed to investigate the effects of SS on H. pylori. The effects of SS on oxygen concentrations in solutions and on H. pylori in vivo and in vitro were examined, and the mechanisms involved were explored. The results showed that SS decreased the oxygen concentration in water and artificial gastric juice. In Columbia blood agar and special peptone broth, SS concentration-dependently inhibited the proliferation of H. pylori ATCC43504 and Sydney strain-1 in Columbia blood agar or special peptone broth, and dose-dependently decreased the number of H. pylori in Mongolian gerbils and Kunming mouse infection models. The H. pylori was relapsed in 2 weeks withdrawal and the recurrence in the SS group was lower than that in the positive triple drug group. These effects were superior to positive triple drugs. After SS treatments, the cell membrane and cytoplasm structure of H. pylori were disrupted. SS-induced oxygen-free environment initially blocked aerobic respiration, triggered oxidative stress, disturbed energy production. In conclusion, SS consumes oxygen and creates an oxygen-free environment in which H. pylori does not survive. The present study provides a new strategy and perspective for the clinical treatment of H. pylori infectious disease.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Animais , Camundongos , Ágar , Peptonas , Modelos Animais de Doenças , Mucosa Gástrica , Gerbillinae
5.
BMC Infect Dis ; 23(1): 284, 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142976

RESUMO

OBJECTIVE: This study aimed to develop and validate a machine learning algorithm-based model for predicting invasive Klebsiella pneumoniae liver abscess syndrome(IKPLAS) in diabetes mellitus and compare the performance of different models. METHODS: The clinical signs and data on the admission of 213 diabetic patients with Klebsiella pneumoniae liver abscesses were collected as variables. The optimal feature variables were screened out, and then Artificial Neural Network, Support Vector Machine, Logistic Regression, Random Forest, K-Nearest Neighbor, Decision Tree, and XGBoost models were established. Finally, the model's prediction performance was evaluated by the ROC curve, sensitivity (recall), specificity, accuracy, precision, F1-score, Average Precision, calibration curve, and DCA curve. RESULTS: Four features of hemoglobin, platelet, D-dimer, and SOFA score were screened by the recursive elimination method, and seven prediction models were established based on these variables. The AUC (0.969), F1-Score(0.737), Sensitivity(0.875) and AP(0.890) of the SVM model were the highest among the seven models. The KNN model showed the highest specificity (1.000). Except that the XGB and DT models over-estimates the occurrence of IKPLAS risk, the other models' calibration curves are a good fit with the actual observed results. Decision Curve Analysis showed that when the risk threshold was between 0.4 and 0.8, the net rate of intervention of the SVM model was significantly higher than that of other models. In the feature importance ranking, the SOFA score impacted the model significantly. CONCLUSION: An effective prediction model of invasion Klebsiella pneumoniae liver abscess syndrome in diabetes mellitus could be established by a machine learning algorithm, which had potential application value.


Assuntos
Diabetes Mellitus , Abscesso Hepático , Humanos , Klebsiella pneumoniae , Estudos Retrospectivos , Aprendizado de Máquina , Síndrome
6.
Ren Fail ; 45(2): 2264935, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37846973

RESUMO

Objective: Peritoneal dialysis (PD) requires high patient conscientiousness. Therefore, we aimed to investigate the relationship between conscientiousness score and prognosis in PD patients.Methods: The ten-item Big Five Personality Inventory's Chinese version was used to assess the conscientiousness score. Basic clinical information, prior medical history, hematological examination results, the occurrence of the first peritonitis and catheter-related infection, the start of hemodialysis, and the time of renal transplantation were collected. The patients were split into two groups, high and low conscientiousness groups, based on the mean value of the conscientiousness score. The differences in prognostic indicators were compared between groups, and the association between conscientiousness score and prognostic indicators in PD patients was assessed.Results: Enrolled PD patients were divided into low conscientiousness group 103 and high conscientiousness group 98. There were significant differences in serum albumin (p = 0.021) and iPTH (p = 0.045) between the two groups. Multivariate Cox regression analysis identified conscientiousness score as an independent risk factor for the development of first peritonitis (HR = 0.558, 95% CI 0.400-0.779, p = 0.001) and first catheter-related infection (HR = 0.544, 95% CI 0.308-0.962, p = 0.036) in PD patients. Conscientiousness score (HR = 2.377, 95% CI 1.109-5.095, p = 0.026) was independently associated with renal transplantation.Conclusion: Conscientiousness personality is closely related to the prognosis of PD patients.


Assuntos
Infecções Relacionadas a Cateter , Falência Renal Crônica , Diálise Peritoneal , Peritonite , Humanos , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Estudos Retrospectivos , Diálise Peritoneal/efeitos adversos , Diálise Peritoneal/métodos , Diálise Renal/efeitos adversos , Prognóstico , Fatores de Risco , Peritonite/epidemiologia , Peritonite/etiologia , Falência Renal Crônica/terapia , Falência Renal Crônica/complicações
7.
Small ; 18(2): e2102477, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34585513

RESUMO

Next-generation desalination technologies are needed to meet the increasing demand for clean water. Capacitive deionization (CDI) is a thermodynamically efficient technique to treat non-potable water with relatively low salinity. The salt removal capacity and rate of CDI are highly dependent on the electrode materials, which are preferentially porous to store ions through electrosorption and/or redox reactions. Metal-organic frameworks (MOFs) with "infinite" combinations of transition metals and organic linkers simplify the production of carbonaceous materials often with redox-active components after pyrolysis. MOFs-derived materials show great tunability in both compositions and structures but require further refinement to improve CDI performance. This review article summarizes recent progress in derivatives of MOFs and MOF-like materials used as CDI electrodes, focusing on the structural and compositional material considerations as well as the processing parameters and electrode architectures of the device. Furthermore, the challenges and opportunities associated with this research area are also discussed.


Assuntos
Estruturas Metalorgânicas , Purificação da Água , Eletrodos , Íons , Salinidade , Purificação da Água/métodos
8.
Eur Radiol ; 31(7): 4824-4838, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33447861

RESUMO

OBJECTIVES: To develop radiomics-based nomograms for preoperative microvascular invasion (MVI) and recurrence-free survival (RFS) prediction in patients with solitary hepatocellular carcinoma (HCC) ≤ 5 cm. METHODS: Between March 2012 and September 2019, 356 patients with pathologically confirmed solitary HCC ≤ 5 cm who underwent preoperative gadoxetate disodium-enhanced MRI were retrospectively enrolled. MVI was graded as M0, M1, or M2 according to the number and distribution of invaded vessels. Radiomics features were extracted from DWI, arterial, portal venous, and hepatobiliary phase images in regions of the entire tumor, peritumoral area ≤ 10 mm, and randomly selected liver tissue. Multivariate analysis identified the independent predictors for MVI and RFS, with nomogram visualized the ultimately predictive models. RESULTS: Elevated alpha-fetoprotein, total bilirubin and radiomics values, peritumoral enhancement, and incomplete or absent capsule enhancement were independent risk factors for MVI. The AUCs of MVI nomogram reached 0.920 (95% CI: 0.861-0.979) using random forest and 0.879 (95% CI: 0.820-0.938) using logistic regression analysis in validation cohort (n = 106). With the 5-year RFS rate of 68.4%, the median RFS of MVI-positive (M2 and M1) and MVI-negative (M0) patients were 30.5 (11.9 and 40.9) and > 96.9 months (p < 0.001), respectively. Age, histologic MVI, alkaline phosphatase, and alanine aminotransferase independently predicted recurrence, yielding AUC of 0.654 (95% CI: 0.538-0.769, n = 99) in RFS validation cohort. Instead of histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest achieved comparable accuracy in MVI stratification and RFS prediction. CONCLUSIONS: Preoperative radiomics-based nomogram using random forest is a potential biomarker of MVI and RFS prediction for solitary HCC ≤ 5 cm. KEY POINTS: • The radiomics score was the predominant independent predictor of MVI which was the primary independent risk factor for postoperative recurrence. • The radiomics-based nomogram using either random forest or logistic regression analysis has obtained the best preoperative prediction of MVI in HCC patients so far. • As an excellent substitute for the invasive histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest (MVI-RF) achieved comparable accuracy in MVI stratification and outcome, reinforcing the radiologic understanding of HCC angioinvasion and progression.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Gadolínio DTPA , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Invasividade Neoplásica , Recidiva Local de Neoplasia/diagnóstico por imagem , Estudos Retrospectivos
9.
Skeletal Radiol ; 50(9): 1821-1828, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33599801

RESUMO

OBJECTIVE: To compare rib fracture detection and classification by radiologists using CT images with and without a deep learning model. MATERIALS AND METHODS: A total of 8529 chest CT images were collected from multiple hospitals for training the deep learning model. The test dataset included 300 chest CT images acquired using a single CT scanner. The rib fractures were marked in the bone window on each CT slice by experienced radiologists, and the ground truth included 861 rib fractures. We proposed a heterogeneous neural network for rib fracture detection and classification consisting of a cascaded feature pyramid network and a classification network. The deep learning-based model was evaluated based on the external testing data. The precision rate, recall rate, F1-score, and diagnostic time of two junior radiologists with and without the deep learning model were computed, and the Chi-square, one-way analysis of variance, and least significant difference tests were used to analyze the results. RESULTS: The use of the deep learning model increased detection recall and classification accuracy (0.922 and 0.863) compared with the radiologists alone (0.812 vs. 0.850). The radiologists achieved a higher precision rate, recall rate, and F1-score for fracture detection when using the deep learning model, at 0.943, 0.978, and 0.960, respectively. When using the deep learning model, the radiologist's reading time was decreased from 158.3 ± 35.7 s to 42.3 ± 6.8 s. CONCLUSION: Radiologists achieved the highest performance in diagnosing and classifying rib fractures on CT images when assisted by the deep learning model.


Assuntos
Fraturas das Costelas , Humanos , Redes Neurais de Computação , Radiologistas , Estudos Retrospectivos , Fraturas das Costelas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
10.
Ren Fail ; 43(1): 391-400, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33632070

RESUMO

BACKGROUND: Cardiomyocyte hypertrophy has been reported as one of the important mechanisms for cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). MiroRNA-21(miR-21) was determined to play an important role in myocardial hypertrophy. However, the role of microvesicles (MVs) containing miR-21 in CKD-related cardiomyocyte hypertrophy remains largely unexplored. METHODS: Renal tubular epithelial cells were stimulated by transforming growth factor (TGF-ß1), and the conditioned medium was extracted by differential centrifugation. Renal tubular epithelial cells were labeled with Dil-C18 dye and the recipient cardiomyocytes were observed by fluorescence microscope. MiR-21 level in MVs was detected by qRT-PCR, and the length and diameter of cardiomyocytes were measured by microscope. BCA protein kit and ANP kit were used to detect the content of cell protein and the level of ANP. MiR-21 inhibitor was transfected into cardiomyocytes to observe the effect of miR-21 on myocardial hypertrophy. RESULTS: TGF-ß1 could induce donor renal tubular epithelial cells to produce MVs and delivered into cardiomyocytes, followed by the diameter, protein concentration and ANP content of cardiomyocytes significantly increased. Meanwhile, MiR-21 levels were markedly increased in MVs isolated from donor renal tubular epithelial cells and recipient cardiomyocytes. Pre-transfection of miR-21 inhibitors could inhibit MV-induced cardiomyocyte hypertrophy. CONCLUSION: Tubular cells could secrete miR-21 by MVs and deliver it into recipient cardiomyocytes to induce cardiomyocyte hypertrophy. It might shed a new light on the mechanism and treatment of CKD-related cardiac dysfunction.


Assuntos
Células Epiteliais/metabolismo , Túbulos Renais/citologia , MicroRNAs/metabolismo , Miócitos Cardíacos/patologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Hipertrofia , Túbulos Renais/metabolismo , MicroRNAs/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Ratos , Transfecção
11.
Artigo em Inglês | MEDLINE | ID: mdl-32071054

RESUMO

Helicobacter pylori is an important risk factor for gastric ulcers. However, antibacterial therapies increase the resistance rate and decrease the eradication rate of H. pylori Inspired by the microaerophilic characteristics of H. pylori, we aimed at effectively establishing an oxygen-enriched environment to eradicate and prevent the recurrence of H. pylori The effect and the mechanism of an oxygen-enriched environment in eradicating H. pylori and preventing the recurrence were explored in vitro and in vivo During oral administration and after drug withdrawal, H. pylori counts were evaluated by Giemsa staining in animal cohorts. An oxygen-enriched environment in which H. pylori could not survive was successfully established by adding hydrogen peroxide into several solutions and rabbit gastric juice. Hydrogen peroxide effectively killed H. pylori in Columbia blood agar and special peptone broth. Minimum inhibition concentrations and minimum bactericidal concentrations of hydrogen peroxide were both relatively stable after promotion of resistance for 30 generations, indicating that hydrogen peroxide did not easily promote resistance in H. pylori In models of Mongolian gerbils and Kunming mice, hydrogen peroxide has been shown to significantly eradicate and effectively prevent the recurrence of H. pylori without toxicity and damage to the gastric mucosa. The mechanism of hydrogen peroxide causing H. pylori death was related to the disruption of bacterial cell membranes. The oxygen-enriched environment achieved by hydrogen peroxide eradicates and prevents the recurrence of H. pylori by damaging bacterial cell membranes. Hydrogen peroxide thus provides an attractive candidate for anti-H. pylori treatment.


Assuntos
Antibacterianos/farmacologia , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Oxigênio/farmacologia , Animais , Antiulcerosos/farmacologia , Membrana Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/fisiologia , Feminino , Mucosa Gástrica/efeitos dos fármacos , Gerbillinae , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Coelhos , Úlcera Gástrica/microbiologia , Úlcera Gástrica/prevenção & controle
12.
Dig Dis ; 38(3): 165-177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31630142

RESUMO

BACKGROUND AND AIM: The etiology and pathogenesis of Barrett's esophagus (BE) have been widely studied during recent decades. However, the association between BE and possible risk factors, including abdominal obesity (AO), metabolic syndrome (MetS), insulin resistance (IR), and the microbiome has not reached a consensus and lacks a systematic assessment. The purpose of our study is to evaluate, quantify, and summarize the association between these factors and BE risk. METHODS: A systematic search of Pubmed, Embase, and Cochrane Library databases was performed to identify relevant studies before September 2018. Studies were estimated with the OR, the weighted mean difference (WMD), and the 95% CI by using a random effects model. Subgroup analysis and publication bias were also performed. RESULTS: A total of 46 citations were included in the analysis, and 119,273 subjects were analyzed (AO 13, MetS 15, IR 9, and microbiome: 9). The pooled results showed that AO (p < 0.01, OR 1.30, 95% CI 1.11-1.52, I2 = 31.9%), MetS (p < 0.01, OR 1.68, 95% CI 1.40-2.01, I2 = 87.6%), and IR (p < 0.01, WMD 0.23, 95% CI 0.11-0.35, I2 = 55.8%) were all significantly associated with an increased risk of BE, but except for the microbiome (p > 0.05, OR 1.27, 95% CI 0.66-2.43, I2 = 46.7%). In addition, subgroup analyses were stratified by waist-to-hip ratio, waist circumference, body mass index, diagnosis criteria, strain type, geographical region, and study design, respectively. Moreover, we observed no evidence of publication bias in Egger's and Begg's tests. CONCLUSIONS: Our study reveals that AO, MetS, and IR are significantly associated with BE risk, except for the microbiome. The mechanism of BE induced by 3 risk factors should be further explored.


Assuntos
Esôfago de Barrett/diagnóstico , Esôfago de Barrett/microbiologia , Resistência à Insulina , Síndrome Metabólica/complicações , Microbiota , Obesidade/complicações , Adulto , Esôfago de Barrett/complicações , Índice de Massa Corporal , Feminino , Humanos , Fatores de Risco
13.
Chemphyschem ; 20(15): 1997-2009, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31177637

RESUMO

In order to determine a material's hydrogen storage potential, capacity measurements must be robust, reproducible, and accurate. Commonly, research reports focus on the gravimetric capacity, and often times the volumetric capacity is not reported. Determining volumetric capacities is not as straight-forward, especially for amorphous materials. This is the first study to compare measurement reproducibility across laboratories for excess and total volumetric hydrogen sorption capacities based on the packing volume. The use of consistent measurement protocols, common analysis, and figure of merits for reporting data in this study, enable the comparison of the results for two different materials. Importantly, the results show good agreement for excess gravimetric capacities amongst the laboratories. Irreproducibility for excess and total volumetric capacities is attributed to real differences in the measured packing volume of the material.

14.
Eur Radiol ; 29(5): 2293-2301, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30560361

RESUMO

OBJECTIVE: To explore the value of texture analysis based on diffusion-weighted imaging (DWI), blood oxygen level-dependent MRI (BOLD), and susceptibility-weighted imaging (SWI) in evaluating renal dysfunction. METHODS: Seventy-two patients (mean age 53.72 ± 13.46 years) underwent MRI consisting of DWI, BOLD, and SWI. According to their estimated glomerular filtration rate (eGFR), the patients were classified into either severe renal function impairment (sRI, eGFR < 30 mL/min/1.73 m2), non-severe renal function impairment (non-sRI, eGFR ≥ 30 mL/min/1.73 m2, and < 80 mL/min/1.73 m2), or control (CG, eGFR ≥ 80 mL/min/1.73 m2) groups. Thirteen texture features were extracted and then were analyzed to select the most valuable for discerning the three groups with each imaging method. A ROC curve was performed to compare the capacities of the features to differentiate non-sRI from sRI or CG. RESULTS: Six features proved to be the most valuable for assessing renal dysfunction: 0.25QuantileDWI, 0.5QuantileDWI, HomogeneityDWI, EntropyBOLD, SkewnessSWI, and CorrelationSWI. Three features derived from DWI (0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI) were smaller in sRI than in non-sRI; EntropyBOLD and CorrelationSWI were smaller in non-sRI than in CG (p < 0.05). 0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI showed similar capacities for differentiating sRI from non-sRI. Similarly, EntropyBOLD and CorrelationSWI showed equal capacities for differentiating non-sRI from CG. CONCLUSION: Texture analysis based on DWI, BOLD, and SWI can assist in assessing renal dysfunction, and texture features based on BOLD and SWI may be suitable for assessing renal dysfunction during early stages. KEY POINTS: • Texture analysis based on MRI techniques allowed for assessing renal dysfunction. • Texture features based on BOLD and SWI, but not DWI, may be suitable for assessing renal function impairment during early stages. • SWI exhibited a similar capacity to BOLD for assessing renal dysfunction.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Taxa de Filtração Glomerular , Rim/diagnóstico por imagem , Rim/fisiopatologia , Oxigênio/sangue , Adulto , Idoso , Feminino , Humanos , Rim/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Curva ROC , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos
15.
Am J Nephrol ; 48(1): 46-55, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30048964

RESUMO

BACKGROUND: Blood oxygen level-dependent (BOLD)-MRI is a novel and noninvasive tool that can assess renal oxygenation. The R2* value is a parameter of tissue deoxyhemoglobin concentration detected by BOLD-MRI. The purpose of the current study was to determine the relationships between renal R2* values and clinical parameters and to determine whether renal R2* values were associated with the risk for progression of chronic kidney disease (CKD). METHODS: Sixty patients with CKD were enrolled in this prospective observational study in China from March 2013 to August 2014. A region of interest-based BOLD-MRI was performed to obtain cortical and medullary R2* (CR2* and MR2*) values. Data on demographics and clinical characteristics were collected. The primary end point (CKD progression) was defined as an absolute 30% decline in the estimated glomerular filtration rates (eGFR; CKD-Epidemiology Collaboration equations) or initiation of dialysis during follow-up. RESULTS: The CR2* and MR2* values in patients with CKD were significantly higher compared with those of healthy controls. The CR2* levels were positively associated with 24-h urinary protein excretion, blood urea nitrogen, creatinine, and uric acid but negatively associated with baseline eGFR, 24-h creatinine clearance, eGFR slope, serum albumin, and the use of angiotensin II type 1 receptor blockade. The CR2* levels had the highest areas under the curve during follow-up compared with the MR2* levels and medullary cortical ratios. The Kaplan-Meier survival analysis showed that patients with CKD in the lowest tertile of the CR2* levels had the best prognosis compared with the other 2 tertiles. Moreover, baseline eGFR and CR2* tertiles were associated with the progression of CKD in Cox proportional hazard regression models. Only CR2* tertiles correlated negatively with the eGFR slope. CONCLUSION: We have demonstrated that the clinical feasibility of BOLD-MRI to evaluate renal oxygenation and cortex hypoxia aggravates with the decline of renal function, and cortex hypoxia was a prognostic marker in the progression of CKD.


Assuntos
Rim/patologia , Imageamento por Ressonância Magnética/métodos , Oxigênio/sangue , Diálise Renal/estatística & dados numéricos , Insuficiência Renal Crônica/mortalidade , Adulto , Idoso , Hipóxia Celular , China/epidemiologia , Progressão da Doença , Estudos de Viabilidade , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Estimativa de Kaplan-Meier , Rim/diagnóstico por imagem , Rim/metabolismo , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Consumo de Oxigênio , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/terapia , Reprodutibilidade dos Testes
16.
Clin Exp Nephrol ; 22(1): 173-178, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28791560

RESUMO

BACKGROUND: Ambulatory blood pressure (ABP) monitoring and carotid-femoral pulse wave velocity (cfPWV) provide important cardiovascular risk information for dialysis patients. This study aims to evaluate the risk factors of cfPWV and the associations between ambulatory blood pressure, especially night-time blood pressure and cfPWV. METHODS: We conducted a cross-sectional study in patients on maintenance hemodialysis. ABP and cfPWV were measured on a midweek interdialytic day. Associations were determined using Pearson's correlation analysis and multiple stepwise regression model. RESULTS: Systolic BPs and pulse pressures, but not diastolic BPs, were significantly and positively associated with cfPWV. In a stepwise regression model, age, diabetes mellitus and all-period systolic BP were independently associated with cfPWV. When day-time and night-time BPs were included in the analysis, respectively, only night-time systolic BP and age remained as independently associated with cfPWV. CONCLUSION: Ambulatory BPs are potent associates of cfPWV and night-time systolic BP, rather than day-time BPs, is an independently predictor of cfPWV. Our results support the view that controlling of nocturnal hypertension provides a unique cardiovascular protection effect.


Assuntos
Pressão Sanguínea , Análise de Onda de Pulso , Diálise Renal , Insuficiência Renal Crônica/fisiopatologia , Adulto , Fatores Etários , Idoso , Monitorização Ambulatorial da Pressão Arterial , Ritmo Circadiano , Estudos Transversais , Diástole , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/terapia , Fatores de Risco , Sístole , Rigidez Vascular
17.
Proc Natl Acad Sci U S A ; 112(34): 10629-34, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26261338

RESUMO

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A ⋅ cm(-3) at 0.9 V or 450 A ⋅ cm(-3) extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.

18.
Nano Lett ; 17(2): 953-962, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28072542

RESUMO

Sodium-ion batteries (SIBs) have been considered as one of the promising power source candidates for the stationary storage industries owing to the much lower cost of sodium than lithium. It is well-known that the electrode materials largely determine the energy density of the battery systems. However, recent discoveries on the electrode materials showed that most of them present distinct lithium and sodium storage performance, which is not yet well understood. In this work, we performed a comparative understanding on the structural changes of porous cobalt oxide during its electrochemical lithiation and sodiation process by in operando synchrotron small angel X-ray scattering, X-ray diffraction, and X-ray absorption spectroscopy. It was found that compared to the lithiation process, the porous cobalt oxide undergoes less pore structure changes, oxidation state, and local structure changes as well as crystal structure evolution during its sodiation process, which is attributed to the intrinsic low sodiation activity of cobalt oxide as evidenced by ab initio molecular dynamics simulations. Moreover, it was indicated that the sodiation activity of metal sulfides is higher than that of metal oxides, indicating a better candidate for SIBs. Such understanding is crucial for future design and improvement of high-performance electrode materials for SIBs.

19.
Nat Mater ; 15(9): 1023-30, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27348576

RESUMO

Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multi-scale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical vapour deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework and random submicrometre voids, and shows an average Young's modulus that is 2-3 orders of magnitude smaller than that of single-crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permits non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems.

20.
Mol Cell Biochem ; 431(1-2): 103-112, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28285359

RESUMO

Esophageal adenocarcinoma (EAC) is one of the most common malignancies in the world which is associated the increased prevalence of obesity. In the context of obesity, leptin can directly contribute to progression of EAC. Adiponectin inhibits leptin-induced oncogenic signaling in EAC cells. However, the exact molecular mechanisms linking obesity, adipokines, and EAC remain far from completely understood. In the present study, we tested the role of ubiquitin-like with PHD and ring finger domains 1 (UHRF1) in adiponectin-induced protective effects against leptin-induced EAC cell proliferation. We found that globular adiponectin (gAD) significantly inhibited leptin-induced increase of cell proliferation and decrease of apoptosis in OE 19 cells. Moreover, leptin-induced increase of UHRF1 expression was suppressed by gAD. Compared with normal controls, UHRF1 expression was markedly increased in EAC tissues and cell lines. Silence of UHRF1 increased the expression of cleaved caspase 3 and 9 and Bax, reduced the expression of Bcl-2, promoted apoptosis, and inhibited cell proliferation in OE 19 cells. Overexpression of UHRF1 significantly blocked gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of adiponectin receptor 1/2 (AdipoR1/2) could inhibit gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of AdipoR2, but not AdipoR1, suppressed gAD-induced decrease of UHRF1 expression in leptin-treated cells. The results indicated that gAD inhibited the prooncogenic effects of leptin via AdipoR2-mediated suppression of UHRF1. Our study provides novel insights into the role of UHRF1 in the development of EAC and the mechanism of antitumor effect of gAD.


Assuntos
Adenocarcinoma/metabolismo , Adiponectina/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/biossíntese , Proliferação de Células , Neoplasias Esofágicas/metabolismo , Leptina/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores de Adiponectina/metabolismo , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Neoplasias Esofágicas/patologia , Humanos , Ubiquitina-Proteína Ligases
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