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1.
Polymers (Basel) ; 13(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806971

RESUMO

Fire-protection coatings with a self-monitoring ability play a critical role in safety and security. An intelligent fire-protection coating can protect humans from personal and property damage. In this work, we report the fabrication of a low-cost and facile intelligent fire coating based on a composite of ammonium polyphosphate and epoxy (APP/EP). The composite was processed using laser scribing, which led to a laser-induced graphene (LIG) layer on the APP/EP surface via a photothermal effect. The C-O, C=O, P-O, and N-C bonds in the flame-retardant APP/EP composite were broken during the laser scribing, while the remaining carbon atoms recombined to generate the graphene layer. A proof-of-concept was achieved by demonstrating the use of LIG in supercapacitors, as a temperature sensor, and as a hazard detection device based on the shape memory effect of the APP/EP composite. The intelligent flame protection coating had a high flame retardancy, which increased the time to ignition (TTI) from 21 s to 57 s, and the limiting oxygen index (LOI) value increased to 37%. The total amount of heat and smoke released during combustion was effectively suppressed by ≈ 71.1% and ≈ 74.1%, respectively. The maximum mass-specific supercapacitance could reach 245.6 F·g-1. The additional LIG layer enables applications of the device as a LIG-APP/EP temperature sensor and allows for monitoring of the deformation according to its shape memory effect. The direct laser scribing of graphene from APP/EP in an air atmosphere provides a convenient and practical approach for the fabrication of flame-retardant electronics.

2.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 33(3): 276-280, 2021 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-33834967

RESUMO

OBJECTIVE: To analysis the risk factors and safety of administration of norepinephrine (NE) via peripheral vein line (PVL) in patients with septic shock. METHODS: A single-center retrospective study was conducted. According to the Lanzhou University Second Hospital information system (HIS) and nursing adverse events report cards, patients with septic shock administrated with NE via PVL to correct the hypotension from January 1st 2015 to December 31st, 2019 were enrolled. The patients' general information, placement location of peripheral venous catheter and venousneedle type, characteristics of NE usage and patient general condition when extravasation occurred were collected. The univariate analysis and Logistic regression were used to analyze risk factors associated with extravasation. Also, the receiver operator characteristic curve (ROC curve) was drawn, and the predictive value of risk factors for extravasation was analyzed. RESULTS: A total of 1 022 cases with NE were enrolled. After a preliminary screening, a total of 910 cases with NE were used to correct low blood pressure, including 116 cases of peripheral venous infusion. The average age was (52.91±18.69) years old, with majority of female (77 cases, 66.4%). Basic diseases were mainly chronic obstructive pulmonary disease (COPD, 100 cases, 86.2%), followed by hypertension (91 cases, 78.4%), coronary heart disease (87 cases, 75.0%), type 2 diabetes (74 cases, 63.8%) respectively, the primary disease was septic shock in 109 cases (94.0%). A total of 147 peripheral venous catheters were inserted, and the most common site of puncture was the forearm [78.9% (116/147)], followed by the hand [12.2% (18/147)] and the median cubital vein [8.8% (13/147)]. 89.9% of the needles were 20 G in diameter, and 75 cases (64.7%) were converted to central venous catheters (CVC) during subsequent treatment due to continuous infusion of NE. Six patients (5.2%) had extravasation, the median time of extravasation was 29 (23-39) hours, and the median time of NE was 23 (11-53) hours, including 2 patients with an infusion concentration of 60 mg/L and 4 patients with an infusion concentration of 120 mg/L.The infusion speed was 0.5-1.0 µg×kg-1×min-1, and the average speed of infusion was (0.75±0.04) µg×kg-1×min-1 when extravasation. Univariate and binary Logistic regression analysis showed that the risk factors related to the occurrence of extravasation included: (1) patient factors: the presence of basic diseases, hypertension [odds ratio (OR) = 3.11, 95% confidence interval (95%CI) was 3.09-3.12, P = 0.001] and edema (OR = 1.79, 95%CI was 1.32-2.99, P = 0.032). (2) Factors of infusion fluid itself: long-term (> 24 hours) infusion (OR = 2.91, 95%CI was 1.04-5.96, P = 0.040), infusion concentration > 60 mg/L (OR = 1.88, 95%CI was 1.32-3.99, P = 0.024), infusion speed > 0.3 µg×kg-1×min-1 (OR = 2.43, 95%CI was 2.38-2.51, P = 0.029) and diameter of needles < 20 G (OR = 3.11, 95%CI was 3.09-3.22, P = 0.033). (3) Medical personnel factors: lack of observation and assessment (OR = 1.09, 95%CI was 1.03-6.77, P = 0.043). The ROC curve analysis showed that: edema, long-term infusion (> 24 hours), infusion rate > 0.3 µg×kg-1×min-1 and diameter of needles < 20 G had a certain predictive value for extravasation of NE through peripheral venous infusion in patients with septic shock, the area under ROC curve (AUC) was 0.610, 0.762, 0.672, 0.629, 95%CI was 0.508-0.713, 0.675-0.849, 0.571-0.772, 0.525-0.732, and P values were 0.044, 0.000, 0.002, 0.019, respectively. CONCLUSIONS: Hypertension, edema, long-term infusion (> 24 hours), infusion concentration > 60 mg/L, infusion speed > 0.3 µg×kg-1×min-1, diameter of needle < 20 G, and lack of observation and evaluation by medical staff regularly were risk factors affecting the safety of peripheral intravenous NE in patients with septic shock. Peripheral NE should be avoided in the presence of the above risk factors.


Assuntos
Diabetes Mellitus Tipo 2 , Choque Séptico , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Norepinefrina , Prognóstico , Estudos Retrospectivos , Choque Séptico/tratamento farmacológico
3.
Sci Prog ; 104(1): 36850421998175, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33787414

RESUMO

The objective of this study was to investigate the efficacy of vitamin C in patients experiencing sepsis and septic shock. The PubMed, Embase and Cochrane Library databases were searched for randomized controlled trials (RCTs) about vitamin C treatments for critically ill patients suffering from sepsis and septic shock from inception until December 31, 2019. The primary outcome was mortality, and the secondary outcomes were the ICU length of stay and the dose of vasopressors. A meta-analysis of nine RCTs with a total of 584 patients (301 in the intervention group and 283 in the control group) was conducted. There were significant differences between the vitamin C group and the control group in 28-day mortality (fixed effects OR = 0.60 95% CI [0.42, 0.85], p = 0.004) and in the dose of vasopressors (SMD = -0.88 95% CI [-1.48, -0.29], p = 0.003); however, the ICU length of stay was the same between the two groups (SMD = -0.33 95% CI [-0.87, 0.20] p = 0.23). This meta-analysis demonstrated that the use of vitamin C (compared with placebo) led to a reduction in ICU mortality and a reduction in the dose of vasopressors in patients with septic shock. However, the ICU length of stay was not significantly different between the two groups. Therefore, multicentre and high-quality RCTs are needed to further clarify the safety and effectiveness of vitamin C among patients with sepsis and septic shock.

4.
ACS Appl Mater Interfaces ; 13(12): 14385-14393, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33736429

RESUMO

Herein, the second-order Jahn-Teller effect was applied to the design of the bismuth ferrite-based ceramics. A large distortion of an electron structure arranged along the z axis and an asymmetric distribution of charge density were calculated in 0.80(0.725BiFeO3-0.275BaTiO3)-0.20PT (0.20 PT) based on the density functional theory, indicating good ferro/piezoelectric properties. The top experimental polarization of 36.89 µC/cm2, optimal d33 value of 258 pC/N measured at room temperature, and ultrahigh d33 value of 303 pC/N measured at 370 °C were obtained at 0.20 PT, thereby further confirming the calculations. Furthermore, a high Curie point of 488 °C, as well as outstanding temperature stability ranging from room temperature to 430 °C of the 0.20 PT ceramic was observed. The domain of the 0.20 PT exhibited greater order and smaller size, resulting in easy switching when applying voltage. The distorted electron structure, plumb grains, ordered and easily switchable domains, and coexistences of tetragonal (T) and rhombohedral (R) phases contributed to the large piezoelectric constant of the 0.2 PT ceramic. BFBT-xPT ceramics are potentially promising for high-temperature piezoelectric field applications.

5.
J Org Chem ; 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33630594

RESUMO

The reactions of C60 with acetone were carried out under basic condition in the presence of 1.0 M TBAOH (tetra-n-butylammonium hydroxide) methanol solution and ArCH2Br (Ar = Ph or o-BrPh), where methano[60]fulleroids with a novel 1,1,4,9,9,25-configuration were obtained and structurally characterized by single crystal diffraction. The product was formed via the ring-opening reaction of the [5,6]-cyclopropane by the nucleophilic addition of MeO-, which is different from the reactions of other ketones reported previously.

6.
Adv Mater ; 33(13): e2006247, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33630383

RESUMO

Despite considerable efforts to prevent lithium (Li) dendrite growth, stable cycling of Li metal anodes with various structures remains extremely difficult due to the direct contact of the liquid electrolyte with Li. Rational design of solid-electrolyte interphase (SEI) for 3D electrodes is a promising but still challenging strategy for preventing Li dendrite growth and avoiding lithium-electrolyte side reactions in Li-metal batteries. Here, a 3D architecture is constructed with g-C3 N4 /graphene/g-C3 N4 insulator-metal-insulator sandwiched nanosheets to guide uniform Li plating/stripping in the van der Waals gap between the graphene and the g-C3 N4 , and the function of which can be regarded as a 3D artificial SEI. Li deposition on the surface of g-C3 N4 is suppressed due to its insulating nature. However, its uniform lithiophilic sites and nanopore channels enable homogeneous lithium plating between the graphene and the g-C3 N4 , prohibiting the direct contact of the electrolyte with the Li metal. The use of the g-C3 N4 -layer-modified 3D anode enables long-term Li deposition with a high Coulombic efficiency and stable cycling of full cells under high cathode loading, limited Li excess, and lean electrolyte conditions. The concept of a 3D artificial SEI will shed light on developing safe and stable Li-metal anodes.

7.
Environ Pollut ; 271: 116378, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33401212

RESUMO

It is highly desirable but remains extremely challenging to develop a facile strategy to prepare adsorbent for dealing with heavy metal pollution in water. Here, we report a facile approach for preparing sulfydryl-functionalized graphene oxide (S-GO) by cross-linking method with an unprecedented adsorption capacity and ultrahigh selectivity for efficient Hg(II) removal. The adsorbents exhibit a prominent performance in capturing Hg(II) from wastewater with a record-high adsorption capacity of 3490 mg/g and rapid kinetics to reduce Hg(II) contaminants below the discharge standard of drinking water (2 ppb) within 60 min under a wide pH range even in the coexistent of other interfering metal ions. In addition, the adsorbents can be also easily recycled and reused multiple times with no apparent decline in removal efficiency. Considering the broad diversity, we developed also a magnetic Fe3O4/S-GO adsorbent by a simple chemical cross-linking reaction to achieve rapid separation of S-GO from their aqueous solution. In addition, the adsorbents were successfully applied in dealing with the practical industrial wastewater. The results indicate the potential of rationally designed sulfydryl-functionalized graphene oxide for high performance Hg(II) removal.


Assuntos
Mercúrio , Poluentes Químicos da Água , Adsorção , Grafite , Concentração de Íons de Hidrogênio , Mercúrio/análise , Água , Poluentes Químicos da Água/análise
8.
Angew Chem Int Ed Engl ; 60(15): 8243-8250, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33434387

RESUMO

Core/shell nanocatalysts are a class of promising materials, which achieve the enhanced catalytic activities through the synergy between ligand effect and strain effect. However, it has been challenging to disentangle the contributions from the two effects, which hinders the rational design of superior core/shell nanocatalysts. Herein, we report precise synthesis of PdCu/Ir core/shell nanocrystals, which can significantly boost oxygen evolution reaction (OER) via the exclusive strain effect. The heteroepitaxial coating of four Ir atomic layers onto PdCu nanoparticle gives a relatively thick Ir shell eliminating the ligand effect, but creates a compressive strain of ca. 3.60%. The strained PdCu/Ir catalysts can deliver a low OER overpotential and a high mass activity. Density functional theory (DFT) calculations reveal that the compressive strain in Ir shell downshifts the d-band center and weakens the binding of the intermediates, causing the enhanced OER activity. The compressive strain also boosts hydrogen evolution reaction (HER) activity and the strained nanocrystals can be served as excellent catalysts for both anode and cathode in overall water-splitting electrocatalysis.

9.
J Ethnopharmacol ; 264: 113381, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32946961

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Recently, a new drug combination GRS comprising ginsenoside Rb1 (G-Rb1), ruscogenin (R-Rus) and schisandrin (S-SA) was screened based on ShengMai preparations, which exhibited a prominent cardioprotective effects against myocardial ischemia/reperfusion (MI/R) injury. AIM OF THE STUDY: To investigate their systemic and individual mechanism of each compound in combination GRS. MATERIALS AND METHODS: The mice model of MI/R and hypoxia/reoxygenation (H/R)-induced cardiomyocytes injury were performed to explore the respective characteristics of each compound in GRS against myocardial injury. RESULTS: Each component in the combination GRS attenuated MI/R injury as evidenced by decreased myocardial infarct size, ameliorated histological features, and improved biochemical indicators. Meanwhile, ingredient G, R and S in combination also individually performed a significant decrease of apoptotic index in MI/R mice and H/R-induced cardiomyocytes injury. Mechanistically, component G in GRS could markedly increase the ATP content in cardiomyocytes through activation of AMPKα phosphorylation. Interestingly, the anti-apoptotic actions of G were profoundly attenuated by knockdown of AMPKα, while no alteration was observed on composition R and S. Moreover, component R in GRS significantly reduced the IL-6 and TNF-α mRNA expression, as well as the content of IL-6 via the modulation of NF-κB signaling pathway. Further, component S exhibited the most powerful anti-oxidative capacity in GRS and remarkably decreased the production of MDA and ROS, and potential mechanisms might at least in part through activating the Akt-14-3-3 signaling pathway and inhibiting the phosphorylation of Bad and ERK1/2. CONCLUSIONS: Our results indicated that the respective mechanism of each compound in combination GRS against MI/R injury might closely associated with energy metabolism modulation, suppression of inflammation and oxidative stress.


Assuntos
Ciclo-Octanos/administração & dosagem , Medicamentos de Ervas Chinesas/administração & dosagem , Ginsenosídeos/administração & dosagem , Lignanas/administração & dosagem , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Compostos Policíclicos/administração & dosagem , Espirostanos/administração & dosagem , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Ciclo-Octanos/isolamento & purificação , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/isolamento & purificação , Ginsenosídeos/isolamento & purificação , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Lignanas/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos ICR , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Compostos Policíclicos/isolamento & purificação , Ratos , Espirostanos/isolamento & purificação , Resultado do Tratamento
10.
Math Biosci Eng ; 17(6): 7353-7377, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33378900

RESUMO

Remote sensing image classification exploiting multiple sensors is a very challenging problem: The traditional methods based on the medium- or low-resolution remote sensing images always provide low accuracy and poor automation level because the potential of multi-source remote sensing data are not fully utilized and the low-level features are not effectively organized. The recent method based on deep learning can efficiently improve the classification accuracy, but as the depth of deep neural network increases, the network is prone to be overfitting. In order to address these problems, a novel Two-channel Densely Connected Convolutional Networks (TDCC) is proposed to automatically classify the ground surfaces based on deep learning and multi-source remote sensing data. The main contributions of this paper includes the following aspects: First, the multi-source remote sensing data consisting of hyperspectral image (HSI) and Light Detection and Ranging (LiDAR) are pre-processed and re-sampled, and then the hyperspectral data and LiDAR data are input into the feature extraction channel, respectively. Secondly, two-channel densely connected convolutional networks for feature extraction were proposed to automatically extract the spatial-spectral feature of HSI and LiDAR. Thirdly, a feature fusion network is designed to fuse the hyperspectral image features and LiDAR features. The fused features were classified and the output result is the category of the corresponding pixel. The experiments were conducted on popular dataset, the results demonstrate that the competitive performance of the TDCC with respect to classification performance compared with other state-of-the-art classification methods in terms of the OA, AA and Kappa, and it is more suitable for the classification of complex ground surfaces.

11.
ACS Nano ; 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33253548

RESUMO

Improving the sulfur loading in cathodes is a significant challenge for practical lithium-sulfur batteries. Although carbonaceous sulfur hosts can achieve higher sulfur content and loading, the low tap densities of carbonaceous materials lead to low volumetric energy densities, restricting practical application. Here, conductive porous laminated vanadium nitride (VN) as a carbon-free sulfur host has been successfully developed to construct high tap density, high sulfur loading, and high energy density sulfur electrodes. The laminated stacking multiscale VN featuring interconnected holes possesses high storage space for sulfur loading, achieving high sulfur loading and utilization. VN@S materials' sulfur content and tap density can achieve 80 wt % and 1.17 g cm-3, respectively. At the sulfur loading of 1.0 mg cm-2, the VN@S cathode reaches the reversible capacity of 790 mAh g-1 at 1 C after 200 cycles and 145.2 mAh g-1 at 15 C after 500 cycles. Precisely, at a high sulfur loading of 12.6 mg cm-2, the VN@S cathode delivers a reversible capacity of 518.8 mAh g-1 (485.6 mAh cm-3) at 0.1 C after 100 cycles.

12.
J Hazard Mater ; : 124470, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33189464

RESUMO

We herein report a facile strategy to prepare poly(allylamine hydrochloride) cross-linked amino-modified graphene oxide (PAH-ASGO) by Schiff-base reactions. The resulting PAH-ASGO exhibited a maximum adsorption capacity of 373.1 mg/g for Cr(VI), which was nearly 9 times higher than that of pure graphene oxide, exceeding that of most GO-based materials previously reported. More significantly, PAH-ASGO can effectively diminish the Cr(VI) concentration from 9.9 mg/L to the extremely low level of 0.004 mg/L within 10 s, far below the maximum allowable level of Cr(VI) (0.05 mg/L) in drinking water. In addition, the adsorbents still displayed excellent removal efficiency of 91.8% after 10 cycles. Considering the broad diversity, we developed also a magnetic PAH-ASGO/Fe3O4 adsorbent by a simple cross-linking reaction to achieve rapid separation of PAH-ASGO from their aqueous solution. Finally, the PAH-ASGO was successfully utilized to treat the actual industrial effluent.

13.
PeerJ ; 8: e9675, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194342

RESUMO

Objective: To explore the relationship between body mass index (BMI) and clinicopathological characteristics in patients with papillary thyroid carcinoma (PTC). Methods: The clinical data of 1,579 patients with PTC, admitted to our hospital from May 2016 to March 2017, were retrospectively analyzed. According to the different BMI of patients, it can be divided into underweight recombination (BMI < 18.5 kg/m), normal body recombination (18.5 ≤ BMI < 24.0 kg/m2), overweight recombination (24.0 ≤ BMI < 28.0 kg/m2) and obesity group (BMI ≥ 28.0 kg/m2). The clinicopathological characteristics of PTC in patients with different BMIs group were compared. Results: In our study, the risk for extrathyroidal extension (ETE), advanced T stage (T III/IV), and advanced tumor-node-metastasis stage (TNM III/IV) in the overweight group were higher, with OR (odds ratio) = 1.99(1.41-2.81), OR = 2.01(1.43-2.84), OR = 2.94(1.42-6.07), respectively, relative to the normal weight group. The risk for ETE and T III/IV stage in the obese group were higher, with OR = 1.82(1.23-2.71) and OR = 1.82(1.23-2.70), respectively, relative to the normal weight group. Conclusion: BMI is associated with the invasiveness of PTC. There is a higher risk for ETE and TNM III/IV stage among patients with PTC in the overweight group and for ETE among patients with PTC in the obese group.

14.
Environ Sci Technol ; 54(23): 15476-15488, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33156618

RESUMO

Industrialization has resulted in the rapid increase of volatile organic compound (VOC) emissions, which have caused serious issues to human health and the environment. In this study, an extensive Cu incorporating TiO2 induced nucleophilic oxygen structure was constructed in the CuTiOx catalyst, which exhibited superior low-temperature catalytic activity for C3H6 combustion. Thorough structural, surface characterization and density functional theory (DFT) calculations revealed that the Cu-O-Ti hybridization induced nucleophilic oxygen initiates C3H6 combustion by abstracting the C-H bond. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results indicated that incorporated copper species acted as the major adsorbent site for the propene molecule. In combination of the DRIFTS and DFT results, the promotion effect of the nucleophilic O on the C-H bond abstraction and CO2 formation pathway was proposed. The surface doping induced nucleophilic oxygen as strong Brønsted basic sites for low-temperature propene combustion exemplified an efficient strategy for rational design of next-generation environmental catalysts.

15.
Polymers (Basel) ; 12(11)2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33138265

RESUMO

Derivatives of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]undecane-3,9-dioxide (SPDPC) are of increasing interest as flame retardants for polymeric materials. In addition, SPDPC is also an important intermediate for the preparation of intumescent flame retardants (IFRs). However, low efficiency and undesirable dispersion are two major problems that seriously restrain the application of IFRs as appropriate flame retardants for polymer materials. Usually, the functionalization or modification of SPDPC is crucial to acquiring high-performance polymer composites. Here, a small molecule spirocyclic flame retardant diphenylimidazole spirocyclic pentaerythritol bisphosphonate (PIPC) was successfully prepared through the substitution reaction between previously synthesized intermediate SPDPC and 2-phenylimidazole (PIM). Phenyl group and imidazole group were uniformly anchored on the molecular structure of SPDPC. This kind of more uniform distribution of flame retardant groups within the epoxy matrix resulted in a synergistic flame retardant effect and enhanced the strength of char layers to the epoxy composites, when compared to the unmodified epoxy. The sample reached a limiting oxygen index (LOI) of 29.7% and passed with a V-0 rating in the UL 94 test with the incorporation of only 5 wt % of as-prepared flame retardant PIPC. Moreover, its peak of heat release rate (pHRR) and total heat release (THR) decreased by 41.15% and 21.64% in a cone calorimeter test, respectively. Furthermore, the addition of PIPC has only slightly impacted the mechanical properties of epoxy composites with a low loading.

16.
Chem Commun (Camb) ; 56(92): 14385-14388, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33140747

RESUMO

Allosteric effects are common in biology, but have not been fully explored in the control of supramolecular polymerization. Herein, ditopic UPy derivatives with acyclic crown ether-like spacers were designed and synthesized, which can undergo supramolecular polymerization through quadruple hydrogen bonding. Upon the addition of K+, drastic molecular conformational change to the U-shape is induced by metal-coordination, reconfiguring remote UPy sites towards the formation of discrete cyclic dimers. Interestingly, the supramolecular polymerization can be restored by simply removing K+ by water-extraction.

17.
Pregnancy Hypertens ; 23: 11-17, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33161224

RESUMO

BACKGROUND: The flavonoid, luteolin, promotes vasorelaxation in various arteries through endothelial-dependent and independent mechanisms. Although there is growing interest in the vasoactive effects of flavonoids on maternal vascular function during pregnancy, it is unknown whether luteolin elicits vasorelaxation in the uterine circulation. We tested the hypothesis that luteolin induces vasorelaxation via endothelial-dependent mechanisms in uterine arteries from normal pregnant rats during late gestation. METHODS: Uterine arteries and aortas were isolated from Sprague-Dawley rats at gestational day 19 and prepared for wire myography. RESULTS: The potency of luteolin-induced vasorelaxation was examined between uterine arteries and the aortas. By 50 µM of luteolin, there was complete relaxation (100.5 ± 5.2%) in uterine arteries as compared to aortas (27.5 ± 10.0%). Even the highest concentration of 100 µM luteolin produced less than half relaxation (43.6 ± 8.6%) in aortas compared to uterine arteries. We then explored if luteolin-induced vasorelaxation in uterine arteries from pregnant rats was mediated by endothelial-dependent vasorelaxation pathways, including nitric oxide synthase (NOS), cyclooxygenase (COX), or potassium (K+) channels. Blocking these pathways with N(G)-Nitro-l-arginine methyl ester hydrochloride (L-NAME), indomethacin, or tetraethylammonium (TEA)/high potassium chloride (KCl), respectively, did not alter luteolin responses in uterine arteries from pregnant rats. These findings suggested that endothelial factors may not mediate luteolin-induced vasorelaxation in uterine arteries during pregnancy. Indeed, experiments where the endothelium was removed did not alter luteolin-induced vasorelaxation in uterine arteries during pregnancy. CONCLUSIONS: Luteolin directly promotes vasorelaxation in the medial smooth muscle layer of uterine arteries during normal pregnancy.

18.
In Vitro Cell Dev Biol Anim ; 56(9): 715-722, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33067659

RESUMO

Myocardial infarction is the leading cause of death worldwide, and cardiomyocyte apoptosis during myocardial infarction and reperfusion is a significant factor of poor prognosis. As important regulatory molecules, biofunctions of circRNAs in the pathogenesis of myocardial infarction remain elusive. To confirm the expression level and biological function of circNFIX in cardiomyocytes upon oxidative stress. Divergent polymerase chain reaction and Sanger sequencing were performed to verify the circular structure. The stability of circNFIX was confirmed by RNase R treatment and actinomycin D assay. In order to simulate oxidative stress during myocardial infarction, H9c2 cells were subjected to hydrogen peroxide and hypoxia stimulation. In vivo, mouse models of myocardial ischemia were established. The biological function of circNFIX in cardiomyocytes was investigated through loss- and gain-of-function assays, and cardiomyocyte apoptosis level was detected by the terminal deoxyribonucleotidyl transferase-mediated TdT-mediated dUTP nick end labeling assay and Western blot. CircNFIX is abundant, conserved, and stable in H9c2 cells. The expression of circNFIX was significantly downregulated in cardiomyocytes subjected to oxidative stress. Enforced CircNFIX promotes H9c2 cells apoptosis induced by hydrogen peroxide, in sharp contrast to circNFIX knockdown. In this study, we found that circNFIX served as a pro-apoptosis factor in cardiomyocyte apoptosis. CircNFIX possesses potential to be the biomarker and therapeutic target in myocardial infarction.

19.
Eur J Cardiothorac Surg ; 58(5): 969-974, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33084867

RESUMO

OBJECTIVES: We aimed to investigate the safety, feasibility and early and mid-term outcomes of total repair of elective tetralogy of Fallot through a right subaxillary thoracotomy. METHODS: Between May 2010 and September 2015, a retrospective review of patients with elective tetralogy of Fallot undergoing primary repair through a right subaxillary thoracotomy was performed. This study included 47 patients [27 males, 20 females; the mean age of 1.7 ± 1.5 years (ranging from 3 to 106 months); body weight of 9.7 ± 2.8 kg (ranging from 5 to 16 kg); McGoon ratio ≥1.5]. The ventricular septal defects were approached through a right atriotomy in 30 patients, a right ventriculotomy in 8 patients and the combination of a right atriotomy and ventriculotomy in 9 patients. Transannular and non-transannular patches were used in 20 and 27 patients, respectively. RESULTS: There was 1 operative death (2.1%), and the others recovered uneventfully. The median cardiopulmonary bypass and aortic cross-clamping times was 79 ± 20.8 (45-136) and 50 ± 15.7 (25-94) min, respectively. The mechanical ventilation time, length of intensive care unit and postoperative hospital stay were 0.9 ± 0.6, 2.6 ± 1.1 and 10.7 ± 2.7 days, respectively. The main complications involved low cardiac output syndrome in 5 patients, arrhythmia in 6 patients, pulmonary infection in 4 patients, small residual shunt in 2 patients, mild residual right ventricular outflow tract obstruction in 2 patients, mild tricuspid regurgitation in 3 patients and atelectasis in 1 patient. The mean follow-up time was 82 ± 22.0 months, and no late deaths occurred during the follow-up. One (2.1%) patient received reintervention for residual significant pulmonary artery stenosis. That was in addition to 2 (4.3%) patients having mild residual right ventricular outflow tract, 1 (2.1%) patient with moderate tricuspid regurgitation and 3 (6.4%) patients with moderate pulmonary valve regurgitation to be followed up. CONCLUSIONS: The right subaxillary thoracotomy, providing a safe and feasible alternative, can be performed with a low mortality rate and satisfactory early and mid-term outcomes for total repair of elective tetralogy of Fallot.

20.
Mol Neurobiol ; 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32997292

RESUMO

Parkinson's disease (PD) is a neurodegenerative disease caused by a variety of unclear complex pathogenic factors. The 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine/probenecid (MPTP/p)-induced progressive PD mice is a well-recognized classic model for studying PD, but the molecular toxicology of this model is still unclear. Here, for the first time, we report gradual neurodegenerative processes in MPTP/p-induced progressive PD mice model using RNA-seq. Transcriptional responses are orchestrated to regulate the expression of many genes in substantia nigra, such as Ntf3, Pitx3, Th, and Drd2, leading to the degeneration of dopaminergic neurons at last. We proposed that the established model could be divided into three phases based on their molecular toxicological features: "the stress response phase" which maintained the microenvironment homeostasis, "the pre-neurodegenerative phase" which demonstrated observed MPTP/p cytotoxicity and gradual degeneration of dopaminergic neurons, and "the neurodegenerative phase" which reflected distinct damage and dopaminergic neuron apoptotic process. Glia cells exhibited a certain protective effect on dopaminergic neurons in 3rd and 6th MPTP/p-induced cytotoxicity. But in 10th MPTP/p injection, glia cells play a promoting role in PD and tissue damages caused by oxidative stress. This study also indicated that the substantia nigra of PD mice showed unique patterns of changes at each stage. Moreover, neurotrophic signaling pathway, ECM-receptor interaction, oxidative phosphorylation, apoptosis and necroptosis were enriched at 3rd and 6th MPTP/p injection, which might be associated with the PD progress. This study provided an extensive data set of molecular toxicology for elucidating of PD progression and offered comprehensive theoretical knowledge for the development of new therapy.

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