Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
1.
J Am Chem Soc ; 146(20): 14349-14356, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38742424

RESUMO

High-purity CO2 rather than dilute CO2 (15 vol %, CO2/N2/O2 = 15:80:5, v/v/v) similar to the flue gas is currently used as the feedstock for the electroreduction of CO2, and the liquid products are usually mixed up with the cathode electrolyte, resulting in high product separation costs. In this work, we showed that a microporous conductive Bi-based metal-organic framework (Bi-HHTP, HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) can not only efficiently capture CO2 from the dilute CO2 under high humidity but also catalyze the electroreduction of the adsorbed CO2 into formic acid with a high current density of 80 mA cm-2 and a Faradaic efficiency of 90% at a very low cell voltage of 2.6 V. Importantly, the performance in a dilute CO2 atmosphere was close to that under a high-purity CO2 atmosphere. This is the first catalyst that can maintain exceptional eCO2RR performance in the presence of both O2 and N2. Moreover, by using dilute CO2 as the feedstock, a 1 cm-2 working electrode coating with Bi-HHTP can continuously produce a 200 mM formic acid aqueous solution with a relative purity of 100% for at least 30 h in a membrane electrode assembly (MEA) electrolyzer. The product does not contain electrolytes, and such a highly concentrated and pure formic acid aqueous solution can be directly used as an electrolyte for formic acid fuel cells. Comprehensive studies revealed that such a high performance might be ascribed to the CO2 capture ability of the micropores on Bi-HHTP and the lower Gibbs free energy of formation of the key intermediate *OCHO on the open Bi sites.

2.
J Am Chem Soc ; 145(49): 26783-26790, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38014883

RESUMO

The electroreduction of CO2 into value-added liquid fuels holds great promise for addressing global environmental and energy challenges. However, achieving highly selective yielding of multi-carbon oxygenates through the electrochemical CO2 reduction reaction (eCO2RR) is a formidable task, primarily due to the sluggish asymmetric C-C coupling reaction. In this study, a novel metal-organic framework (CuSn-HAB) with unprecedented heterometallic Sn···Cu dual sites (namely, a pair of SnN2O2 and CuN4 sites bridged by µ-N atoms) was designed to overcome this limitation. CuSn-HAB demonstrated an impressive Faradic efficiency (FE) of 56(2)% for eCO2RR to alcohols, achieving a current density of 68 mA cm-2 at a low potential of -0.57 V (vs RHE). Notably, no significant degradation was observed over a continuous 35 h operation at the specified current density. Mechanistic investigations revealed that, in comparison to the copper site, the SnN2O2 site exhibits a higher affinity for oxygen atoms. This enhanced affinity plays a pivotal role in facilitating the generation of the key intermediate *OCH2. Consequently, compared to homometallic Cu···Cu dual sites (generally yielding ethylene product), the heterometallic dual sites were proved to be more thermodynamically favorable for the asymmetric C-C coupling between *CO and *OCH2, leading to the formation of the key intermediate *CO-*OCH2, which is favorable for yielding ethanol product.

3.
Front Aging Neurosci ; 15: 1216905, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37794977

RESUMO

Introduction: Early diagnosis of Parkinson's disease (PD) remains challenging. It has been suggested that abnormal brain iron metabolism leads to excessive iron accumulation in PD, although the mechanism of iron deposition is not yet fully understood. Ferritin and transferrin receptor (TfR) are involved in iron metabolism, and the exosome pathway is one mechanism by which ferritin is transported and regulated. While the blood of healthy animals contains a plentiful supply of TfR-positive exosomes, no studies have examined ferritin and TfR in plasma neural-derived exosomes. Methods: Plasma exosomes were obtained from 43 patients with PD and 34 healthy controls. Neural-derived exosomes were isolated with anti-human L1CAM antibody immunoabsorption. Transmission electron microscopy and western blotting were used to identify the exosomes. ELISAs were used to quantify ferritin and TfR levels in plasma neural-derived exosomes of patients with PD and controls. Receivers operating characteristic (ROC) curves were applied to map the diagnostic accuracy of ferritin and TfR. Independent predictors of the disease were identified using logistic regression models. Results: Neural-derived exosomes exhibited the typical exosomal morphology and expressed the specific exosome marker CD63. Ferritin and TfR levels in plasma neural-derived exosomes were significantly higher in patients with PD than controls (406.46 ± 241.86 vs. 245.62 ± 165.47 ng/µg, P = 0.001 and 1728.94 ± 766.71 vs. 1153.92 ± 539.30 ng/µg, P < 0.001, respectively). There were significant positive correlations between ferritin and TfR levels in plasma neural-derived exosomes in control group, PD group and all the individuals (rs = 0.744, 0.700, and 0.752, respectively). The level of TfR was independently associated with the disease (adjusted odds ratio 1.002; 95% CI 1.000-1.003). ROC performances of ferritin, TfR, and their combination were moderate (0.730, 0.812, and 0.808, respectively). However, no relationship was found between the biomarkers and disease progression. Conclusion: It is hypothesized that ferritin and TfR in plasma neural-derived exosomes may be potential biomarkers for PD, and that they may participate in the mechanism of excessive iron deposition in PD.

4.
J Am Chem Soc ; 145(39): 21672-21678, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37732812

RESUMO

It is challenging and important to achieve high performance for an electrochemical CO2 reduction reaction (eCO2RR) to yield CH4 under neutral conditions. So far, most of the reported active sites for eCO2RR to yield CH4 are single metal sites; the performances are far below the commercial requirements. Herein, we reported a nanosheet metal-organic layer in single-layer, namely, [Cu2(obpy)2] (Cuobpy-SL, Hobpy = 1H-[2,2']bipyridinyl-6-one), possessing dicopper(I) sites for eCO2RR to yield CH4 in a neutral aqueous solution. Detailed examination of Cuobpy-SL revealed high performance for CH4 production with a faradic efficiency of 82(1)% and a current density of ∼90 mA cm-2 at -1.4 V vs. reversible hydrogen electrode (RHE). No obvious degradation was observed over 100 h of continuous operation, representing a remarkable performance to date. Mechanism studies showed that compared with the conventional single-copper sites and completely exposed dicopper(I) sites, the dicopper(I) sites in the confined space formed by the molecular stacking have a strong affinity to key C1 intermediates such as *CO, *CHO, and *CH2O to facilitate the CH4 production, yet inhibiting C-C coupling.

5.
J Am Chem Soc ; 145(31): 16978-16982, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37526259

RESUMO

The electrochemical CO2 reduction reaction (eCO2RR) under acidic conditions has become a promising way to achieve high CO2 utilization because of the inhibition of undesirable carbonate formation that typically occurs under neutral and alkaline conditions. Herein, unprecedented and highly active ditin(IV) sites were integrated into the nanopores of a metal-organic framework, namely NU-1000-Sn, by a "ship-in-a-bottle" strategy. NU-1000-Sn delivers nearly 100% formic acid Faradaic efficiency at an industry current density of 260 mA cm-2 with a high single-pass CO2 utilization of 95% in an acidic solution (pH = 1.67). No obvious degradation was observed over 15 hours of continuous operation at the current density of 260 mA cm-2, representing the remarkable eCO2RR performance in acidic electrolyte to date. The mechanism study shows that both oxygen atoms of the key intermediate *HCOO can coordinate to the two adjacent Sn atoms in a ditin(IV) site simultaneously. Such bridging coordination is conducive to the hydrogenation of CO2, thus leading to high performance.

6.
Nanomicro Lett ; 15(1): 120, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37127819

RESUMO

The real structure and in situ evolution of catalysts under working conditions are of paramount importance, especially for bifunctional electrocatalysis. Here, we report asymmetric structural evolution and dynamic hydrogen-bonding promotion mechanism of an atomically dispersed electrocatalyst. Pyrolysis of Co/Ni-doped MAF-4/ZIF-8 yielded nitrogen-doped porous carbons functionalized by atomically dispersed Co-Ni dual-metal sites with an unprecedented N8V4 structure, which can serve as an efficient bifunctional electrocatalyst for overall water splitting. More importantly, the electrocatalyst showed remarkable activation behavior due to the in situ oxidation of the carbon substrate to form C-OH groups. Density functional theory calculations suggested that the flexible C-OH groups can form reversible hydrogen bonds with the oxygen evolution reaction intermediates, giving a bridge between elementary reactions to break the conventional scaling relationship.

7.
Chem Asian J ; 18(15): e202300281, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37147935

RESUMO

Herein, a stable metal-azolate framework with cyclic trinickel(II) clusters, namely [Ni3 (µ3 -O)(BTPP)(OH)(H2 O)2 ] (Ni-BTPP, H3 BTPP=1,3,5-tris((1H-pyrazol-4-yl)phenylene)benzene), achieved a current density of 50 mA cm-2 at a cell voltage of 1.8 V in 1.0 M KOH solution, while the current density of 20%Pt/C@NF||IrO2 @NF is just 35.8 mA cm-2 at 2.0 V under the same condition. Moreover, no obvious degradation was observed over 12 hours of continuous operation at a large current density of 50 mA cm-2 . Theoretical calculations revealed that the µ3 -O atom in the cyclic trinickel(II) cluster serves as hydrogen-bonding acceptor to facilitate the dissociation of a H2 O molecule adsorbed on the adjacent Ni(II) ion, giving a lower energy barrier of H2 O dissociation compared with Pt/C; meanwhile, the µ3 -O atom can also participate in the water oxidation reaction to couple with the adjacent *OH adsorbed on Ni(II) ion, providing a low-energy coupling pathway, thus Ni-BTPP achieves a high performance for overall water splitting.

8.
Angew Chem Int Ed Engl ; 62(22): e202301767, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36823343

RESUMO

The development of efficient electrocatalysts with non-copper metal sites for electrochemical CO2 reduction reactions (eCO2 RR) to hydrocarbons and oxygenates is highly desirable, but still a great challenge. Herein, a stable metal-organic framework (DMA)4 [Sn2 (THO)2 ] (Sn-THO, THO6- = triphenylene-2,3,6,7,10,11-hexakis(olate), DMA = dimethylammonium) with isolated and distorted octahedral SnO6 2- active sites is reported as an electrocatalyst for eCO2 RR, showing an exceptional performance for eCO2 RR to the CH4 product rather than the common products formate and CO for reported Sn-based catalysts. The partial current density of CH4 reaches a high value of 34.5 mA cm-2 , surpassing most reported copper-based and all non-Cu metal-based catalysts. Our experimental and theoretical results revealed that the isolated SnO6 2- active site favors the formation of key *OCOH species to produce CH4 and can greatly inhibit the formation of *OCHO and *COOH species to produce *HCOOH and *CO, respectively.

10.
Angew Chem Int Ed Engl ; 61(44): e202210985, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36068177

RESUMO

Electroreduction of CO2 to CO is a promising approach for the cycling use of CO2 , while it still suffers from impractical current density and durability. Here we report a single-atom nanozyme (Ni-N5 -C) that achieves industrial-scale performance for CO2 -to-CO conversion with a Faradaic efficiency (FE) exceeded 97 % over -0.8--2.4 V vs. RHE. The current density at -2.4 V vs. RHE reached a maximum of 1.23 A cm-2 (turnover frequency of 69.7 s-1 ) with an FE of 99.6 %. No obvious degradation was observed over 100 hours of continuous operation. Compared with the planar Ni-N4 site, the square-pyramidal Ni-N5 site has an increase and a decrease in the d z 2 ${{{\rm d}}_{{z}^{2}}}$ and dxz/yz orbital energy levels, respectively, as revealed by density functional theory calculations. Thus, the Ni-N5 catalytic site is more superior to activate CO2 molecule and reduce the energy barriers as well as promote the CO desorption, thus boosting the kinetic activation process and catalytic activity.

11.
J Am Chem Soc ; 144(29): 13319-13326, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35776438

RESUMO

Crystalline porous materials sustained by supramolecular interactions (e.g., π-π stacking interactions) are a type of molecular crystals showing considerable stability, but their applications are rarely reported due to the high difficulty of their construction. Herein, a stable π-π stacking framework formed by a trinuclear copper(I) compound [Cu3(HBtz)3(Btz)Cl2] (CuBtz, HBtz = benzotriazole) with pyrazolate-bridged dicopper(I) sites is reported and employed for electrochemical CO2 reduction, showing an impressive performance of 73.7 ± 2.8% Faradaic efficiency for C2+ products [i.e., ethylene (44%), ethanol (21%), acetate (4.7%), and propanol (4%)] with a current density of 7.9 mA cm-2 at the potential of -1.3 V versus RHE in an H-type cell and a Faradic efficiency (61.6%) of C2+ products with a current density of ≈1 A cm-2 and a reaction rate of 5639 µmol m-2 s-1 at the potential of -1.6 V versus RHE in a flow cell device, representing an impressive performance reported to date. In-situ infrared spectroscopy, density functional theory calculations, and control experiments revealed that the uncoordinated nitrogen atoms of benzotriazolates in the immediate vicinity can act as proton relays and cooperate with the dicopper(I) site to promote the hydrogenation process of the *CO intermediate and the C-C coupling, resulting in the highly selective electroreduction of CO2 to C2+ products.


Assuntos
Dióxido de Carbono , Prótons , Cobre , Porosidade , Propanóis
12.
Angew Chem Int Ed Engl ; 61(36): e202206470, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-35697663

RESUMO

Electroreduction of CO2 to acetate provides a promising strategy to reduce CO2 emissions and store renewable energy, but acetate is usually a by-product. Here, we show a stable and conductive two-dimensional phthalocyanine-based covalent-organic framework (COF) as an electrocatalyst for reduction of CO2 to acetate with a single-product Faradaic efficiency (FE) of 90.3(2)% at -0.8 V (vs. RHE) and a current density of 12.5 mA cm-2 in 0.1 M KHCO3 solution. No obvious degradation was observed over 80 hours of continuous operation. Combined with the comparison of the properties of other catalysts with isolated metal active sites, theoretical calculations and in situ infrared spectroscopy revealed that the isolated copper-phthalocyanine active site with high electron density is conducive to the key step of C-C coupling of *CH3 with CO2 to produce acetate, and can avoid the coupling of *CO with *CO or *CHO to produce ethylene and ethanol.

13.
Eur Radiol ; 32(11): 7374-7385, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35486169

RESUMO

OBJECTIVES: To systematically assess the early detection rate of biochemical prostate cancer recurrence using choline, fluciclovine, and PSMA. METHODS: Under the guidance of the Preferred Reporting Items for Systematic reviews and Meta-Analysis Diagnostic Test Accuracy guidelines, literature that assessed the detection rates (DRs) of choline, fluciclovine, and PSMA in prostate cancer biochemical recurrence was searched in PubMed and EMBASE databases for our systematic review from 2012 to July 15, 2021. In addition, the PSA-stratified performance of detection positivity was obtained to assess the DRs for various methods, including fluciclovine, PSMA, or choline PET/CT, with respect to biochemical recurrence based on different PSA levels. RESULTS: In total, 64 studies involving 11,173 patients met the inclusion criteria. Of the studies, 12, 7, and 48 focused on choline, fluciclovine, and PSMA, respectively. The pooled DRs were 24%, 37%, and 44%, respectively, for a PSA level less than 0.5 ng/mL (p < 0.001); 36%, 44%, and 60% for a PSA level of 0.5-0.99 ng/mL (p < 0.001); and 50%, 61%, and 80% for a PSA level of 1.0-1.99 ng/mL (p < 0.001). The DR with 18F-labeled PSMA was higher than that with 68Ga-labeled PSMA, and the DR was 58%, 72%, and 88% for PSA levels < 0.5 ng/mL, 0.5-0.9 ng/mL, and 1.0-1.99 ng/mL, respectively. CONCLUSION: The DRs of PSMA-radiotracers were greater than those of choline-radiotracers and fluciclovine-radiotracers at the patient level. 18F-labeled PSMA achieved a higher DR than 68Ga-labeled PSMA. KEY POINTS: • The DRs of PSMA-radiotracers were greater than those of choline-radiotracers and fluciclovine-radiotracers at the patient level. • 18F-labeled PSMA achieved a higher DR than 68Ga-labeled PSMA.


Assuntos
Radioisótopos de Gálio , Neoplasias da Próstata , Masculino , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Antígeno Prostático Específico , Recidiva Local de Neoplasia/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Colina
14.
Chem Commun (Camb) ; 57(95): 12764-12767, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34730142

RESUMO

Here, we report an improved tandem catalytic mechanism for electroreduction of CO2 to C2H4. Cu(111) nanoparticles with an average size of 5.5 ± 0.9 nm were anchored on a conductive Cu-based metal-organic framework (Cu-THQ) by in situ electrochemical synthesis. Compared to Cu(111) nanoparticles, the C2H4 faradaic efficiency of the tandem catalyst Cu(111)@Cu-THQ was increased doubly.

15.
World J Clin Cases ; 9(26): 7886-7892, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34621842

RESUMO

BACKGROUND: Intrahepatic biliary cystadenoma (IBC) is a rare benign hepatic tumor that is often misdiagnosed as other hepatic cystic diseases. Therefore, imaging examinations are required for preoperative diagnosis. Contrast-enhanced ultrasound (CEUS) has gained increasing popularity as an emerging imaging modality and it is considered the primary method for screening IBC because of its specificity of performance. We describe an unusual case of monolocular IBC and emphasize the performance of CEUS. CASE SUMMARY: A 45-year-old man complained of epigastric pain lasting 1 wk. He had no medical history of hepatitis, liver cirrhosis or parasitization. Physical examination revealed a mass of approximately 6 cm in size in the upper abdomen below the subxiphoid process. Tumor marker tests found elevated CA19-9 levels (119.3 U/mL), but other laboratory tests were unremarkable. Ultrasound and computerized tomography revealed a round thick-walled mass measuring 83 mm × 68 mm located in the left lateral lobe of the liver that lacked internal septations and manifested as a monolocular cystic structure. CEUS demonstrated that in the arterial phase, the anechoic area manifested as a peripheral ring with homogeneous enhancement. The central part presented with no enhancement. During the portal phase, the enhanced portion began to subside but was still above the surrounding liver tissue. The patient underwent left partial liver lobectomy and recovered well without tumor recurrence or metastasis. Eventually, the results of pathological examination confirmed IBC. CONCLUSION: A few IBC cases present with monolocular characteristics, and the lack of intracystic septa in imaging performance cannot exclude IBC.

16.
Front Oncol ; 11: 710909, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568038

RESUMO

BACKGROUND: Accurate evaluation of lymph node (LN) status is critical for determining the treatment options in patients with non-small cell lung cancer (NSCLC). This study aimed to develop and validate a 18F-FDG PET-based radiomic model for the identification of metastatic LNs from the hypermetabolic mediastinal-hilar LNs in NSCLC. METHODS: We retrospectively reviewed 259 patients with hypermetabolic LNs who underwent pretreatment 18F-FDG PET/CT and were pathologically confirmed as NSCLC from two centers. Two hundred twenty-eight LNs were allocated to a training cohort (LN = 159) and an internal validation cohort (LN = 69) from one center (7:3 ratio), and 60 LNs were enrolled to an external validation cohort from the other. Radiomic features were extracted from LNs of PET images. A PET radiomics signature was constructed by multivariable logistic regression after using the least absolute shrinkage and selection operator (LASSO) method with 10-fold cross-validation. The PET radiomics signature (model 1) and independent predictors from CT image features and clinical data (model 2) were incorporated into a combined model (model 3). A nomogram was plotted for the complex model, and the performance of the nomogram was assessed by its discrimination, calibration, and clinical usefulness. RESULTS: The area under the curve (AUC) values of model 1 were 0.820, 0.785, and 0.808 in the training, internal, and external validation cohorts, respectively, showing good diagnostic efficacy for lymph node metastasis (LNM). Furthermore, model 2 was able to discriminate metastatic LNs in the training (AUC 0.780), internal (AUC 0.794), and external validation cohorts (AUC 0.802), respectively. Model 3 showed optimal diagnostic performance among the three cohorts, with an AUC of 0.874, 0.845, and 0.841, respectively. The nomogram based on the model 3 showed good discrimination and calibration. CONCLUSIONS: Our study revealed that PET radiomics signature, especially when integrated with CT imaging features, showed the ability to identify true and false positives of mediastinal-hilar LNM detected by PET/CT in patients with NSCLC, which would help clinicians to make individual treatment decisions.

17.
Ann Clin Lab Sci ; 51(3): 302-309, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34162559

RESUMO

OBJECTIVE: The aim of this study was to investigate the effects and mechanism of thalidomide on pancreatic stellate cell (PSC) activation in mice and to find the optimal timing of thalidomide administration. METHODS: PSCs, isolated from mouse pancreas tissue, were divided into five groups with specific treatments: (A) control PSCs (PSC), (B) PSCs induced by TGF-ß1 (PSC+TGF-ß1), (C) PSCs induced by TGF-ß1 followed by thalidomide (PSC+TGF-ß1+Thalidomide), (D) PSCs receiving TGF-ß1 and thalidomide simultaneously (PSC+(TGF-ß1+Thalidomide)), and (E) PSCs treated with thalidomide only (PSC+Thalidomide). We measured the effects of thalidomide on PSC activation by detecting the expression of α-SMA, collagen type I, and the TGF-ß/Smad pathway through quantitative real-time PCR and Western blot analysis. RESULTS: Compared with TGF-ß1 alone, thalidomide significantly inhibited PSC activation by reducing α-SMA expression (P<0.05) and decreasing collagen type I deposition (P<0.05). PSCs treated with thalidomide alone showed lower expression of α-SMA and collagen type I than those treated with thalidomide and TGF-ß1 at random order (P<0.01). Thalidomide downregulated TGF-ß1 and Smad3 and upregulated Smad7 (P<0.05). CONCLUSION: Thalidomide could repress PSC activation and alleviate fibrosis by regulating the TGF-ß/Smad pathway. Preventive use of thalidomide had maximum effect, and there was no evidence for the reversal of the activation of quiescent PSCs.


Assuntos
Inibidores da Angiogênese/farmacologia , Células Estreladas do Pâncreas/efeitos dos fármacos , Proteína Smad3/metabolismo , Proteína Smad7/metabolismo , Talidomida/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Actinas/genética , Actinas/metabolismo , Animais , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Estreladas do Pâncreas/metabolismo , Transdução de Sinais , Proteína Smad3/genética , Proteína Smad7/genética , Fator de Crescimento Transformador beta/genética
18.
Eur J Radiol ; 141: 109809, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34116452

RESUMO

PURPOSE: We sought to evaluate the diagnostic performance of diffusion weighted imaging (DWI) and intravoxel incoherent motion (IVIM) for distinguishing between benign and malignant breast tumors by performing a meta-analysis. METHODS: We comprehensively searched the electronic databases PubMed and Embase from January 2000 to April 2020 for studies in English. Studies were included if they reported the sensitivity and specificity for identifying benign and malignant breast lesions using DWI or IVIM. Studies were reviewed according to QUADAS-2. The data inhomogeneity and publication bias were also assessed. In order to explore the influence of different field strengths and different b values on diagnostic efficiency, we conducted subgroup analysis. RESULTS: We analyzed 79 studies, which included a total of 6294 patients with 4091 malignant lesions and 2793 benign lesions. Overall, the pooled sensitivity and specificity of ADC for detecting malignant breast tumors were 0.87 (0.86-0.88) and 0.80 (0.78-0.81), respectively. The PLR was 5.09 (4.16-6.24); the NLR was 0.15 (0.13-0.18); and the DOR was 38.95 (28.87-52.54). The AUC value was 0.9297. The highest performing parameter for IVIM was tissue diffusivity (D), and the pooled sensitivity and specificity was 0.85 (0.82-0.88) and 0.87(0.83-0.90), respectively; the PLR was 5.65 (3.91-8.18); the NLR was 0.17 (0.12-0.26); and the DOR was 38.44 (23.57-62.69). The AUC value was 0.9265. Most of parameters demonstrated considerable statistically significant heterogeneity (P < 0.05, I2>50 %) except the pooled DOR, PLR of D and the pooled DOR and NLR of D*. CONCLUSIONS: Our meta-analysis indicated that DWI and IVIM had high sensitivity and specificity in the differential diagnosis of breast lesions; and compared with DWI, IVIM could not further increase the diagnostic performance. There was no significant difference in diagnostic accuracy.


Assuntos
Neoplasias da Mama , Imagem de Difusão por Ressonância Magnética , Mama/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Movimento (Física) , Sensibilidade e Especificidade
19.
Rep Prog Phys ; 84(6)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33740777

RESUMO

Given its briefness and predictability, the minimal seesaw-a simplified version of the canonical seesaw mechanism with only two right-handed neutrino fields-has been studied in depth and from many perspectives, and now it is being pushed close to a position of directly facing experimental tests. This article is intended to provide an up-to-date review of various phenomenological aspects of the minimal seesaw and its associated leptogenesis mechanism in neutrino physics and cosmology. Our focus is on possible flavor structures of such benchmark seesaw and leptogenesis scenarios and confronting their predictions with current neutrino oscillation data and cosmological observations. In this connection particular attention will be paid to the topics of lepton number violation, lepton flavor violation, discrete flavor symmetries, CP violation and antimatter of the Universe.

20.
Stem Cell Res ; 51: 102175, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33485186

RESUMO

PARK7 mutations are accountable for the inherited Parkinson's disease. An induced pluripotent stem cell (iPSC) line FJMUUHi001-A was generated by expressing five reprogramming factors, OCT3/4, SOX2, c-MYC, KLF4 and BCL-XL, in peripheral blood mononuclear cells from a 32-year old patient carrying a homozygous mutation of c.189dupA in PARK7. The iPSCs with a normal karyotype had the abilities to differentiate into three germ layers and expressed pluripotency markers without detectable residual plasmids. The cell line FJMUUHi001-A carrying the truncating protein PARK7 could be a useful tool to help comprehend the function of PARK7 in the iPSCs and differentiated cells from them.


Assuntos
Células-Tronco Pluripotentes Induzidas , Doença de Parkinson , Adulto , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Humanos , Fator 4 Semelhante a Kruppel , Leucócitos Mononucleares , Mutação/genética , Doença de Parkinson/genética , Proteína Desglicase DJ-1
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA