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1.
Artigo em Inglês | MEDLINE | ID: mdl-38839057

RESUMO

Phase transitions play an important role in tuning the physical properties of two-dimensional (2D) materials as well as developing their high-performance device applications. Here, we reported the observation of a phase transition in few-layered MoTe2 flakes by the irradiation of gallium (Ga+) ions using a focused ion beam (FIB) system. The semiconducting 2H phase of MoTe2 can be controllably converted to the metallic 1T'-like phase via Te defect engineering during irradiations. By taking advantage of the nanometer-sized Ga+ ion probe proved by FIB, in-plane 1T'-2H homojunctions of MoTe2 at submicrometer scale can be fabricated. Furthermore, we demonstrate the improvement of device performance (on-state current over 2 orders of magnitude higher) in MoTe2 transistors using the patterned 1T'-like phase regions as contact electrodes. Our study provides a new strategy to drive the phase transitions in MoTe2, tune their properties, and develop high-performance devices, which also extends the applications of FIB technology in 2D materials and their devices.

2.
Nat Commun ; 15(1): 4219, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760340

RESUMO

The limited durability of metal-nitrogen-carbon electrocatalysts severely restricts their applicability for the oxygen reduction reaction in proton exchange membrane fuel cells. In this study, we employ the chemical vapor modification method to alter the configuration of active sites from FeN4 to the stable monosymmetric FeN2+N'2, along with enhancing the degree of graphitization in the carbon substrate. This improvement effectively addresses the challenges associated with Fe active center leaching caused by N-group protonation and free radicals attack due to the 2-electron oxygen reduction reaction. The electrocatalyst with neoteric active site exhibited excellent durability. During accelerated aging test, the electrocatalyst exhibited negligible decline in its half-wave potential even after undergoing 200,000 potential cycles. Furthermore, when subjected to operational conditions representative of fuel cell systems, the electrocatalyst displayed remarkable durability, sustaining stable performance for a duration exceeding 248 h. The significant improvement in durability provides highly valuable insights for the practical application of metal-nitrogen-carbon electrocatalysts.

3.
Abdom Radiol (NY) ; 49(5): 1557-1568, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38441631

RESUMO

OBJECTIVE: To developed a magnetic resonance imaging (MRI) radiomics nomogram to identify adenocarcinoma at the cervix-corpus junction originating from the endometrium or cervix in order to better guide clinical treatment. METHODS: Between February 2011 and September 2021, the clinicopathological data and MRI in 143 patients with histopathologically confirmed cervical adenocarcinoma (CAC, n = 86) and endometrioid adenocarcinoma (EAC, n = 57) were retrospectively analyzed at the cervix-corpus junction. Radiomics features were extracted from fat-suppressed T2-weighted imaging (FS-T2WI), diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, and delayed phase contrast-enhanced T1-weighted imaging (CE-T1WI) sequences. A radiomics nomogram was developed integrating radscore with independent clinical risk factors. The area under the curve (AUC) was used to evaluate the diagnostic efficacy of the radscore, nomogram and two different experienced radiologists in differentiating CAC from EAC at the cervix-corpus junction, and Delong test was applied to compare the differences of their diagnostic performance. RESULTS: In the training cohort, the AUC was 0.93 for radscore; 0.97 for radiomics nomograms; 0.85 and 0.86 for radiologists 1 and 2, respectively. Delong test showed that the differential efficacy of nomogram was significant better than those of radiologists in the training cohort (both P < 0.05). CONCLUSIONS: The nomogram based on radscore and clinical risk factors could better differentiate CAC from EAC at the cervix-corpus junction than radiologists, and preoperatively and non-invasively identify the origin of adenocarcinoma at the cervix-corpus junction, which facilitates clinicians to make individualized treatment decision.


Assuntos
Adenocarcinoma , Carcinoma Endometrioide , Neoplasias do Endométrio , Imageamento por Ressonância Magnética Multiparamétrica , Nomogramas , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Carcinoma Endometrioide/diagnóstico por imagem , Carcinoma Endometrioide/patologia , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Adulto , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Idoso , Diagnóstico Diferencial , Colo do Útero/diagnóstico por imagem , Colo do Útero/patologia , Meios de Contraste , Radiômica
4.
Small ; : e2310250, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38295142

RESUMO

The commercialization of rechargeable Zn-air batteries (ZABs) relies on the material innovation to accelerate the sluggish oxygen electrocatalysis kinetics. Due to the differentiated mechanisms of reverse processes, i.e., oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), rationally integrating dual sites for bifunctional oxygen electrocatalysis is prerequisite yet remains challenging. Herein, multicomponent synergistic active sites within highly graphitic carbon substrate are exquisitely constructed, which is accomplished by fluorine (F) modulation strategy. The incorporation of F dopants facilitates pyridinic N formation for anchoring single metal sites, thus guaranteeing the coexistence of sufficient M-Nx sites and metal nanoparticles toward bifunctional oxygen electrocatalysis. As a result, the optimal catalyst, denoted as F NH2 -FeNi-800, outperforms commercial Pt/C+RuO2 with smaller gap between Ej = 10 and E1/2 (ΔE) of 0.63 V (vs 0.7 V for Pt/C+RuO2 ), demonstrating its superior bifunctionality. Beyond that, its superiority is validated in homemade rechargeable ZABs. ZABs assembled using F NH2 -FeNi-800 as the air cathode delivers higher peak power density (123.8 mW cm-2 ) and long-cycle lifetime (over 660 cycles) in comparison with Pt/C@RuO2 (68.8 mW cm-2 ; 300 cycles). The finding not only affords a highly promising oxygen electrocatalyst, but also opens an avenue to constructing multifunctional active sites for heterogeneous catalysts.

5.
Angew Chem Int Ed Engl ; 63(7): e202315119, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38129317

RESUMO

Alleviating the degradation issue of Pt based alloy catalysts, thereby simultaneously achieving high mass activity and high durability in proton exchange membrane fuel cells (PEMFCs), is highly challenging. Herein, we provide a new paradigm to address this issue via delaying the place exchange between adsorbed oxygen species and surface Pt atoms, thereby inhibiting Pt dissolution, through introducing rare earth bonded subsurface oxygen atoms. We have succeeded in introducing Gd-O dipoles into Pt3 Ni via a high temperature entropy-driven process, with direct spectral evidence attained from both soft and hard X-ray absorption spectroscopies. The higher rated power of 0.93 W cm-2 and superior current density of 562.2 mA cm-2 at 0.8 V than DOE target for heavy-duty vehicles in H2 -air mode suggest the great potential of Gd-O-Pt3 Ni towards practical application in heavy-duty transportation. Moreover, the mass activity retention (1.04 A mgPt -1 ) after 40 k cycles accelerated durability tests is even 2.4 times of the initial mass activity goal for DOE 2025 (0.44 A mgPt -1 ), due to the weakened Pt-Oads bond interaction and the delayed place exchange process, via repulsive forces between surface O atoms and those in the sublayer. This work addresses the critical roadblocks to the widespread adoption of PEMFCs.

6.
Br J Radiol ; 96(1151): 20221063, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37660398

RESUMO

OBJECTIVES: Preoperative identification of POLE mutation status would help tailor the surgical procedure and adjuvant treatment strategy. This study aimed to explore the feasibility of developing a radiomics model to pre-operatively predict the pathogenic POLE mutation status in patients with EC. METHODS: The retrospective study involved 138 patients with histopathologically confirmed EC (35 POLE-mutant vs 103 non-POLE-mutant). After selecting relevant features with a series of steps, three radiomics signatures were built based on axial fat-saturation T2WI, DWI, and CE-T1WI images, respectively. Then, two radiomics models which integrated features from T2WI + DWI and T2WI + DWI+CE-T1WI were further developed using multivariate logistic regression. The performance of the radiomics model was evaluated from discrimination, calibration, and clinical utility aspects. RESULTS: Among all the models, radiomics model2 (RM2), which integrated features from all three sequences, showed the best performance, with AUCs of 0.885 (95%CI: 0.828-0.942) and 0.810 (95%CI: 0.653-0.967) in the training and validation cohorts, respectively. The net reclassification index (NRI) and integrated discrimination improvement (IDI) analyses indicated that RM2 had improvement in predicting POLE mutation status when compared with the single-sequence-based signatures and the radiomics model1 (RM1). The calibration curve, decision curve analysis, and clinical impact curve suggested favourable calibration and clinical utility of RM2. CONCLUSIONS: The RM2, fusing features from three sequences, could be a potential tool for the non-invasive preoperative identification of patients with POLE-mutant EC, which is helpful for developing individualized therapeutic strategies. ADVANCES IN KNOWLEDGE: This study developed a potential surrogate of POLE sequencing, which is cost-efficient and non-invasive.


Assuntos
Neoplasias do Endométrio , Humanos , Feminino , Estudos Retrospectivos , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/genética , Área Sob a Curva , Imageamento por Ressonância Magnética , Mutação
7.
Genes (Basel) ; 14(7)2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37510389

RESUMO

Despite the worldwide distribution and rich diversity of the infraorder Bibionomorpha in Diptera, the characteristics of mitochondrial genomes (mitogenomes) are still little-known, and the phylogenetics and evolution of the infraorder remains controversial. In the present study, we report complete and annotated mitogenome sequences of Penthetria simplioipes and Plecia hardyi representing Bibionidae. This is the first report of the complete mitogenomes for the superfamily Bibionoidea. There are 37 genes in each of the complete mitogenomes of all 20 studied species from eight families of four superfamilies within infraorder Bibionomorpha. The Ka/Ks analysis suggests that all 13 PCGs have undergone purifying selection. The gene rearrangement events exist in some families (Keroplatidae, Sciaridae, and Cecidomyiidae) but not in Mycetophilidae in Sciaroidea and also in Scatopsoidea, Anisopodoidea, and Bibionoidea, which suggests that these rearrangement events are derived in the late period in the evolution of the Bibionomorpha. The phylogenetic analysis suggests the phylogenetic relationships of Scatopsoidea + (Anisopodoidea + (Bibionoidea + Sciaroidea)) in Bibionomorpha. The divergence time analysis suggests that Bibionomorpha originated in the Triassic, Scatopsoidea and Anisopodoidea in the late Triassic, Bibionoidea in the Jurassic, and Sciaroidea in the Jurassic to the Cretaceous. The work lays a base for the study of mitogenomes in Bibionomorpha but further work and broader taxon sampling are necessary for a better understanding of the phylogenetics and evolution of the infraorder.


Assuntos
Dípteros , Genoma Mitocondrial , Animais , Dípteros/genética , Filogenia , Genoma Mitocondrial/genética , Nematóceros/genética
8.
Eur Radiol ; 33(8): 5814-5824, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37171486

RESUMO

OBJECTIVES: To develop a fusion model based on clinicopathological factors and MRI radiomics features for the prediction of recurrence risk in patients with endometrial cancer (EC). METHODS: A total of 421 patients with histopathologically proved EC (101 recurrence vs. 320 non-recurrence EC) from four medical centers were included in this retrospective study, and were divided into the training (n = 235), internal validation (n = 102), and external validation (n = 84) cohorts. In total, 1702 radiomics features were respectively extracted from areas with different extensions for each patient. The extreme gradient boosting (XGBoost) classifier was applied to establish the clinicopathological model (CM), radiomics model (RM), and fusion model (FM). The performance of the established models was assessed by the discrimination, calibration, and clinical utility. Kaplan-Meier analysis was conducted to further determine the prognostic value of the models by evaluating the differences in recurrence-free survival (RFS) between the high- and low-risk patients of recurrence. RESULTS: The FMs showed better performance compared with the models based on clinicopathological or radiomics features alone but with a reduced tendency when the peritumoral area (PA) was extended. The FM based on intratumoral area (IA) [FM (IA)] had the optimal performance in predicting the recurrence risk in terms of the ROC, calibration curve, and decision curve analysis. Kaplan-Meier survival curves showed that high-risk patients of recurrence defined by FM (IA) had a worse RFS than low-risk ones of recurrence. CONCLUSIONS: The FM integrating intratumoral radiomics features and clinicopathological factors could be a valuable predictor for the recurrence risk of EC patients. CLINICAL RELEVANCE STATEMENT: An accurate prediction based on our developed FM (IA) for the recurrence risk of EC could facilitate making an individualized therapeutic decision and help avoid under- or over-treatment, therefore improving the prognosis of patients. KEY POINTS: • The fusion model combined clinicopathological factors and radiomics features exhibits the highest performance compared with the clinicopathological model and radiomics model. • Although higher values of area under the curve were observed for all fusion models, the performance tended to decrease with the extension of the peritumoral region. • Identifying patients with different risks of recurrence, the developed models can be used to facilitate individualized management.


Assuntos
Neoplasias do Endométrio , Imageamento por Ressonância Magnética , Humanos , Feminino , Estudos Retrospectivos , Prognóstico , Estimativa de Kaplan-Meier , Neoplasias do Endométrio/diagnóstico por imagem
9.
Quant Imaging Med Surg ; 13(1): 108-120, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36620141

RESUMO

Background: Microsatellite instability (MSI) status is an important indicator for screening patients with endometrial cancer (EC) who have potential Lynch syndrome (LS) and may benefit from immunotherapy. This study aimed to develop a magnetic resonance imaging (MRI)-based radiomics nomogram for the prediction of MSI status in EC. Methods: A total of 296 patients with histopathologically diagnosed EC were enrolled, and their MSI status was determined using immunohistochemical (IHC) analysis. Patients were randomly divided into the training cohort (n=236) and the validation cohort (n=60) at a ratio of 8:2. To predict the MSI status in EC, the tumor radiomics features were extracted from T2-weighted images and contrast-enhanced T1-weighted images, which in turn were selected using one-way analysis of variance (ANOVA) and the least absolute shrinkage and selection operator (LASSO) algorithm to build the radiomics signature (radiomics score; radscore) model. Five clinicopathologic characteristics were used to construct a clinicopathologic model. Finally, the nomogram model combining radscore and clinicopathologic characteristics was constructed. The performance of the three models was evaluated using receiver operating characteristic (ROC), calibration, and decision curve analyses (DCA). Results: Totals of 21 radiomics features and five clinicopathologic characteristics were selected to develop the radscore and clinicopathological models. The radscore and clinicopathologic models achieved an area under the curve (AUC) of 0.752 and 0.600, respectively, in the training cohort; and of 0.723 and 0.615, respectively, in the validation cohort. The radiomics nomogram model showed improved discrimination efficiency compared with the radscore and clinicopathologic models, with an AUC of 0.773 and 0.740 in the training and validation cohorts, respectively. The calibration curve analysis and DCA showed favorable calibration and clinical utility of the nomogram model. Conclusions: The nomogram incorporating MRI-based radiomics features and clinicopathologic characteristics could be a potential tool for the prediction of MSI status in EC.

10.
Cell Signal ; 105: 110593, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36682592

RESUMO

Tracheal fibrosis is a key abnormal repair process leading to fatal stenosis, characterized by excessive fibroblast activation and extracellular matrix (ECM) deposition. GATA6, a zinc finger-containing transcription factor, is involved in fibroblast activation, while its role in tracheal fibrosis remains obscure. The present study investigated the potential role of GATA6 as a novel regulator of tracheal fibrosis. It was found that GATA6 and α-smooth muscle actin (α-SMA) were obviously increased in tracheal fibrotic granulations and in TGFß1-treated primary tracheal fibroblasts. GATA6 silencing inhibited TGFß1-stimulated fibroblast proliferation and ECM synthesis, promoted cell apoptosis, and inactivated Wnt/ß-catenin pathway, whereas GATA6 overexpression showed the reverse effects. SKL2001, an agonist of Wnt/ß-catenin signaling, restored collagen1a1 and α-SMA expression which was suppressed by GATA6 silencing. Furthermore, in vivo, knockdown of GATA6 ameliorated tracheal fibrosis, as manifested by reduced tracheal stenosis and ECM deposition. GATA6 inhibition in rat tracheas also impaired granulation proliferation, increased apoptosis, and inactivated Wnt/ß-catenin pathway. In conclusion, our findings indicate that GATA6 triggers fibroblast activation, cell proliferation, and apoptosis resistance in tracheal fibrosis via the Wnt/ß-catenin signaling pathway. Targeting GATA6 may represent a promising therapeutic approach for tracheal fibrosis.


Assuntos
Via de Sinalização Wnt , beta Catenina , Animais , Ratos , beta Catenina/metabolismo , Fibroblastos/metabolismo , Fibrose , Traqueia/metabolismo
11.
Chemistry ; 29(12): e202203180, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36378121

RESUMO

Electrochemical production of hydrogen peroxide (H2 O2 ) via two-electron oxygen reduction reaction (ORR) process is emerging as a promising alternative method to the conventional anthraquinone process. To realize high-efficiency H2 O2 electrosynthesis, robust and low cost electrocatalysts have been intensively pursued, among which Co-based catalysts attract particular research interests due to the earth-abundance and high selectivity. Here, we provide a comprehensive review on the advancement of Co-based electrocatalyst for H2 O2 electroproduction. The fundamental chemistry of 2-electron ORR is discussed firstly for guiding the rational design of electrocatalysts. Subsequently, the development of Co-based electrocatalysts involving nanoparticles, compounds and single atom catalysts is summarized with the focus on active site identification, structure regulation and mechanism understanding. Moreover, the current challenges and future directions of the Co-based electrocatalysts are briefly summarized in this review.

12.
J Am Chem Soc ; 144(22): 9661-9671, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35622935

RESUMO

Developing highly active, selective, and stable electrocatalysts for the carbon dioxide reduction reaction (CO2RR) is crucial to establish a CO2 conversion system for industrial implementation and, therefore, to realize an artificially closed carbon loop. This can only be achieved through the rational material design based upon the knowledge of the operational active site at the molecular scale. Enlightened by theoretical screening, herein, we for the first time manipulate a novel Ni-Cu atomic pair configuration toward improved CO2RR performance. Systematic characterizations and theoretical modeling reveal that the secondary Cu metal incorporation positively shifts the Ni 3d orbital energy to the Fermi level and thus accelerates the rate-determining step, *COOH formation. In addition, the intrinsic inactivity of Cu toward the competing hydrogen evolution reaction causes a considerable reaction barrier for water dissociation on the Ni-Cu moiety. Due to these attributes, the as-developed Ni/Cu-N-C catalyst exhibits excellent catalytic activity and selectivity, with a record-high turnover frequency of 20,695 h-1 at -0.6 V (vs RHE) and a maximum Faradaic efficiency of 97.7% for CO production. Furthermore, the dynamic structure evolution monitored by operando X-ray absorption fine-structure spectroscopy unveils the interaction between the Ni center and CO2 molecules and the synergistic effect of the Ni-Cu atomic pair on CO2RR activity.

13.
Br J Radiol ; 95(1134): 20211076, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35312379

RESUMO

OBJECTIVE: To develop a radiomics nomogram based on multiparametric MRI (mpMRI) to pre-operatively predict lymph-vascular space invasion (LVSI) in patients with early-stage cervical cancer. METHODS: This retrospective study included 233 consecutive patients with Stage IB-IIB cervical cancer. According to the ratio of 2:1, 154 patients and 79 patients were randomly assigned to the primary and validation cohorts, respectively. Features with intraclass and interclass correlation coefficient (ICCs) greater than 0.75 were selected for radiomics features. The significant features for predicting LVSI were selected using the least absolute shrinkage and selection operator (LASSO) algorithm based on the primary cohort. The rad-score for each patient was constructed via a linear combination of selected features that were weighted by their respective coefficients. The radiomics nomogram was developed using multivariable logistic regression analysis by incorporating the rad-score and clinical risk factors. RESULTS: A total of 19 radiomics features and 3 clinical risk factors were selected. The rad-score exhibited a good performance in discriminating LVSI with a C-index of 0.76 and 0.81 in the primary and validation cohorts, respectively. The radiomics nomogram also exhibited a good discriminating performance in two cohorts (C-index of 0.78 and 0.82). The calibration curve of the radiomics nomogram demonstrated no significant differences was found between prediction and observation outcomes for the probability of LVSI in two cohorts (p = 0.86 and 0.98, respectively). The decision curve analysis indicated that clinician and patients could benefit from the use of radiomics nomogram and rad-score. CONCLUSION: The nomogram and rad-score could be used conveniently and individually to predict LVSI in patients with early-stage cervical cancer and facilitate the treatment decision for clinician and patients. ADVANCES IN KNOWLEDGE: The nomogram could pre-operatively predict LVSI in early-stage cervical cancer.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias do Colo do Útero , Colo do Útero/diagnóstico por imagem , Feminino , Humanos , Nomogramas , Estudos Retrospectivos , Neoplasias do Colo do Útero/diagnóstico por imagem
14.
Acta Radiol ; 63(10): 1415-1424, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34382429

RESUMO

BACKGROUND: Differentiating adenosquamous carcinoma (ASC) and adenocarcinoma (AC) from squamous cell carcinoma (SCC) precisely is crucial for treatment strategy and prognosis prediction in patients with cervical cancer (CC). PURPOSE: To differentiate ASC and AC from SCC in patients with CC using the apparent diffusion coefficient (ADC) histogram analysis. MATERIAL AND METHODS: A total of 118 patients with histologically diagnosed ASC, AC, and SCC were included. The ADC histogram parameters were extracted from ADC maps. Receiver operating characteristic analysis was performed to evaluate the diagnostic performance of each ADC histogram parameter in differentiating the subtypes of CC. The predictors for histologic subtypes were further selected using univariate and multivariate logistic regression analyses. RESULTS: The ADCmean, ADCmax, ADCP10, ADCP25, ADCP75, ADCP90, ADCmedian, and ADCmode of the ASC were significantly lower than those of the AC; and ADCkurtosis and ADCskewness of the ASC were lower than those of the SCC. The ADCmean, ADCmax, ADCP10, ADCP25, ADCP75, ADCP90, ADCmedian, and ADCmode of AC were significantly higher than those of the SCC. The ADCP10 and ADCP10 + diameter yielded the AUCs of 0.753 and 0.778 in differentiating ASC from AC. The ADCmedian and ADCmedian + diameter yielded the AUCs of 0.807 and 0.838 in differentiating AC from SCC. The ADCskewness yielded the AUC of 0.713 in differentiating ASC from SCC. CONCLUSION: The ADCP10 and ADCP10 + diameter, ADCmedian, and ADCmedian + diameter performed well in differentiating ASC from AC and AC from SCC, respectively. However, ADCskewness exhibited a limited ability in differentiating ASC from SCC.


Assuntos
Adenocarcinoma , Carcinoma Adenoescamoso , Carcinoma de Células Escamosas , Neoplasias do Colo do Útero , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/patologia , Carcinoma Adenoescamoso/diagnóstico por imagem , Carcinoma Adenoescamoso/patologia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Estudos Retrospectivos , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia
15.
ACS Appl Mater Interfaces ; 13(39): 47252-47261, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34546698

RESUMO

Understanding the dynamic process of interfacial charge transfer prior to chemisorption is crucial to the development of electrocatalysis. Recently, interfacial water has been highlighted in transferring protons through the electrode/electrolyte interface; however, the identification of the related structural configurations and their influences on the catalytic mechanism is largely complicated by the amorphous and mutable structure of the electrical double layer (EDL). To this end, sub-nanometric Pt electrocatalysts, potentially offering intriguing activity and featuring fully exposed atoms, are studied to uncover the elusive electrode/electrolyte interface via operando X-ray absorption spectroscopy during the hydrogen evolution reaction (HER). Our results show that the metallic Pt clusters derived from the reduction of sub-nanometric Pt clusters (SNM-Pt) exhibit excellent HER activity, with an only 18 mV overpotential at 10 mA/cm2 and one-magnitude-higher mass activity than commercial Pt/C. More importantly, a unique Pt-interfacial water configuration with a Pt (from Pt clusters)-O (from water) radial distance of approximately 2.5 Å is experimentally identified as the structural foundation for the interfacial proton transfer. Toward high overpotentials, the interfacial water that structurally evolves from "O-close" to "O-far" accelerates the proton transfer and is responsible for the improved reaction rate by increasing the hydrogen coverage.

16.
Tex Heart Inst J ; 48(2)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34139763

RESUMO

To determine whether a community-based physical rehabilitation program could improve the prognosis of patients who had undergone percutaneous coronary intervention after acute myocardial infarction, we randomly divided 164 consecutive patients into 2 groups of 82 patients. Patients in the rehabilitation group underwent 3 months of supervised exercise training, then 9 months of community-based, self-managed exercise; patients in the control group received conventional treatment. The primary endpoint was major adverse cardiac events (MACE) during the follow-up period (25 ± 15.4 mo); secondary endpoints included left ventricular ejection fraction, 6-minute walk distance, and laboratory values at 12-month follow-up. During the study period, the incidence of MACE was significantly lower in the rehabilitation group (13.4% vs 24.4%; P <0.01). Cox proportional hazards regression analysis indicated a significantly lower risk of MACE in the rehabilitation group (hazard ratio=0.56; 95% CI, 0.37-0.82; P=0.01). At 12 months, left ventricular ejection fraction and 6-minute walk distance in the rehabilitation group were significantly greater than those in the control group (both P <0.01), and laboratory values also improved. These findings suggest that community-based physical rehabilitation significantly reduced MACE risk and improved cardiac function and physical stamina in patients who underwent percutaneous coronary intervention after acute myocardial infarction.


Assuntos
Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/cirurgia , Intervenção Coronária Percutânea/efeitos adversos , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
17.
ACS Sens ; 6(3): 752-763, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33306358

RESUMO

The emerging applications of electrochemical gas sensors (EGSs) in Internet of Things-enabled smart city and personal health electronics bring out a new challenge for common EGSs, such as alcohol fuel cell sensors (AFCSs) to reduce the dependence on a pricy Pt catalyst. Here, for the first time, we propose a low-cost novel N,S-codoped metal catalyst (FeNSC) to accelerate oxygen reduction reaction (ORR) and replace the Pt catalyst in the cathode of an AFCS. The optimal FeNSC shows high ORR activity, stability, and alcohol tolerance. Furthermore, the FeNSC-based AFCS not only demonstrates excellent linearity, low detection limit, high stability, and superior sensitivity to that of the commercial Pt/C-based AFCS but also outperforms commercial Pt/C-based AFCS in the exposed cell regarding great linearity, high sensitivity, and great stability. Such a promising sensor performance not just proves the concept of the FeNSC-based ACFS but enlightens the next-generation designs toward low-cost, highly sensitive, and durable EGSs.


Assuntos
Nitrogênio , Oxigênio , Catálise , Eletrodos , Platina
18.
Adv Mater ; 32(49): e2004900, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33150623

RESUMO

Single-atom FeN4 sites at the edges of carbon substrates are considered more active for oxygen electrocatalysis than those in plane; however, the conventional high-temperature pyrolysis process does not allow for precisely engineering the location of the active site down to atomic level. Enlightened by theoretical prediction, herein, a self-sacrificed templating approach is developed to obtain edge-enriched FeN4 sites integrated in the highly graphitic nanosheet architecture. The in situ formed Fe clusters are intentionally introduced to catalyze the growth of graphitic carbon, induce porous structure formation, and most importantly, facilitate the preferential anchoring of FeN4 to its close approximation. Due to these attributes, the as-resulted catalyst (denoted as Fe/N-G-SAC) demonstrates unprecedented catalytic activity and stability for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) by showing an impressive half-wave potential of 0.89 V for the ORR and a small overpotential of 370 mV at 10 mA cm-2 for the OER. Moreover, the Fe/N-G-SAC cathode displays encouraging performance in a rechargeable Zn-air battery prototype with a low charge-discharge voltage gap of 0.78 V and long-term cyclability for over 240 cycles, outperforming the noble metal benchmarks.

19.
ChemSusChem ; 13(24): 6621-6628, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33105072

RESUMO

Deploying the application of Au-based catalysts directly on CO2 reduction reactions (CO2 RR) relies on the simultaneous improvement of mass activity (usually lower than 10 mA mg-1 Au at -0.6 V) and selectivity. To achieve this target, we herein manipulate the interface of small-size Au (3.5 nm) and CeO2 nanoparticles through adjusting the surface charge of Au and CeO2 . The well-regulated interfacial structure not only guarantees the utmost utilization of Au, but also enhances the CO2 adsorption. Consequently, the mass activity (CO) of the optimal AuCeO2 /C catalyst reaches 139 mA mg-1 Au with 97 % CO faradaic efficiency (FECO ) at -0.6 V. Moreover, the strong interaction between Au and CeO2 endows the catalyst with excellent long-term stability. This work affords a charge-guided approach to construct the interfacial structure for CO2 RR and beyond.

20.
J Magn Reson Imaging ; 52(3): 885-896, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32096586

RESUMO

BACKGROUND: Lymph node metastasis (LNM) is a critical risk factor affecting treatment strategy and prognosis in patients with early-stage cervical cancer. PURPOSE: To establish a multiparametric MRI (mpMRI)-based radiomics nomogram for preoperatively predicting LNM status. STUDY TYPE: Retrospective. POPULATION: Among 233 consecutive patients, 155 patients were randomly allocated to the primary cohort and 78 patients to the validation cohort. FIELD STRENGTH: Radiomic features were extracted from a 1.5T mpMRI scan (T1 -weighted imaging [T1 WI], fat-saturated T2 -weighted imaging [FS-T2 WI], contrast-enhanced [CE], diffusion-weighted imaging [DWI], and apparent diffusion coefficient [ADC] maps). ASSESSMENT: The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. The area under the receiver operating characteristics curve (ROC AUC), accuracy, sensitivity, and specificity were also calculated. STATISTICAL TESTS: The least absolute shrinkage and selection operator (LASSO) method was used for dimension reduction, feature selection, and radiomics signature building. Multivariable logistic regression analysis was used to develop the radiomics nomogram. An independent sample t-test and chi-squared test were used to compare the differences in continuous and categorical variables, respectively. RESULTS: The radiomic signature allowed a good discrimination between the LNM and non-LNM groups, with a C-index of 0.856 (95% confidence interval [CI], 0.794-0.918) in the primary cohort and 0.883 (95% CI, 0.809-0.957) in the validation cohort. Additionally, the radiomics nomogram also had a good discriminating performance and yielded good calibration both in the primary and validation cohorts (C-index, 0.882 [95% CI, 0.827-0.937], C-index, 0.893 [95% CI, 0.822-0.964], respectively). Decision curve analysis demonstrated that the radiomics nomogram was clinically useful. DATA CONCLUSION: A radiomics nomogram was developed by incorporating the radiomics signature with the MRI-reported LN status and FIGO stage. This nomogram might be used to facilitate the individualized prediction of LNM in patients with early-stage cervical cancer. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:885-896.


Assuntos
Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias do Colo do Útero , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Imageamento por Ressonância Magnética , Nomogramas , Estudos Retrospectivos , Neoplasias do Colo do Útero/diagnóstico por imagem
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