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1.
Angew Chem Int Ed Engl ; 63(8): e202317942, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38179820

RESUMO

CO2 electroreduction (CO2 R) operating in acidic media circumvents the problems of carbonate formation and CO2 crossover in neutral/alkaline electrolyzers. Alkali cations have been universally recognized as indispensable components for acidic CO2 R, while they cause the inevitable issue of salt precipitation. It is therefore desirable to realize alkali-cation-free CO2 R in pure acid. However, without alkali cations, stabilizing *CO2 intermediates by catalyst itself at the acidic interface poses as a challenge. Herein, we first demonstrate that a carbon nanotube-supported molecularly dispersed cobalt phthalocyanine (CoPc@CNT) catalyst provides the Co single-atom active site with energetically localized d states to strengthen the adsorbate-surface interactions, which stabilizes *CO2 intermediates at the acidic interface (pH=1). As a result, we realize CO2 conversion to CO in pure acid with a faradaic efficiency of 60 % at pH=2 in flow cell. Furthermore, CO2 is successfully converted in cation exchanged membrane-based electrode assembly with a faradaic efficiency of 73 %. For CoPc@CNT, acidic conditions also promote the intrinsic activity of CO2 R compared to alkaline conditions, since the potential-limiting step, *CO2 to *COOH, is pH-dependent. This work provides a new understanding for the stabilization of reaction intermediates and facilitates the designs of catalysts and devices for acidic CO2 R.

2.
Small ; 20(1): e2304196, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37665232

RESUMO

Nanofiber is the critical building block for many biological systems to perform various functions. Artificial assembly of molecules into nanofibers in a controllable and reversible manner will create "smart" functions to mimic those of their natural analogues and fabricate new functional materials, but remains an open challenge especially for nature macromolecules. Herein, the controllable and reversible assembly of nanofiber (CSNF) from natural macromolecules with oppositely charged groups are successfully realized by protonation and deprotonation of charged groups. By controlling the electrostatic interaction via protonation and deprotonation, the size and morphology of the assembled nanostructures can be precisely controlled. A strong electrostatic interaction contributes to large nanofiber with high strength, while poor electrostatic interaction produces finer nanofiber or nanoparticle. And especially, the assembly, disassembly, and reassembly of the nanofiber occurs reversibly through protonation and deprotonation, thereby paving a new way for precisely controlling the assembly process and structure of nanofiber. The reversible assembly allows the nanostructure to dynamically reorganize in response to subtle perturbation of environment. The as-prepared CSNF is mechanical strong and can be used as a nano building block to fabricate high-strength film, wire, and straw. This study offers many opportunities for the biomimetic synthesis of new functional materials.

3.
Small ; 19(43): e2302768, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37381638

RESUMO

The Li-CO2 battery has great potential for both CO2 utilization and energy storage, but its practical application is limited by low energy efficiency and short cycle life. Efficient cathode catalysts are needed to address this issue. Herein, this work reports on molecularly dispersed electrocatalysts (MDEs) of nickel phthalocyanine (NiPc) anchored on carbon nanotubes (CNTs) as the cathode catalyst for Li-CO2 batteries. The dispersed NiPc molecules efficiently catalyze CO2 reduction, while the conductive and porous CNTs networks facilitate CO2 evolution reaction, leading to enhanced discharging and charging performance compared to the NiPc and CNTs mixture. Octa-cyano substitution on NiPc (NiPc-CN) further enhances the interaction between the molecule and CNTs, resulting in better cycling stability. The Li-CO2 battery with the NiPc-CN MDE cathode shows a high discharge voltage of 2.72 V and a small discharging-charging potential gap of 1.4 V, and can work stably for over 120 cycles. The reversibility of the cathode is confirmed by experimental characterizations. This work lays a foundation for the development of molecular catalysts for Li-CO2 battery cathodes.

4.
Food Chem Toxicol ; 158: 112633, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34699923

RESUMO

Streptozotocin (STZ) is a pancreatic ß cell-specific toxicant that is widely used to generate models of diabetes in rodents as well as in the treatment of tumors derived from pancreatic ß cells. DNA alkylation, oxidative stress and mitochondrial toxicity have been recognized as the mechanisms for STZ-induced pancreatic ß cell damage. Here, we found that pancreatic ß cell-specific deficiency of nuclear factor erythroid-derived factor 2-related factor 1 (NFE2L1), a master regulator of the cellular adaptive response to a variety of stresses, in mice led to a dramatic resistance to STZ-induced hyperglycemia. Indeed, fifteen days subsequent to last dosage of STZ, the pancreatic ß cell specific Nfe2l1 knockout [Nfe2l1(ß)-KO] mice showed reduced hyperglycemia, improved glucose tolerance, higher plasma insulin and more intact islets surrounded by exocrine acini compared to the Nfe2l1-Flox control mice with the same treatment. Immunohistochemistry staining revealed a greater amount of insulin-positive cells in the pancreas of Nfe2l1(ß)-KO mice than those in Nfe2l1-Flox mice 15 days after the last STZ injection. In line with this observation, both isolated Nfe2l1(ß)-KO islets and Nfe2l1-deficient MIN6 (Nfe2l1-KD) cells were resistant to STZ-induced toxicity and apoptosis. Furthermore, pretreatment of the MIN6 cells with glycolysis inhibitor 2-Deoxyglucose sensitized Nfe2l1-KD cells to STZ-induced toxicity. These findings demonstrated that loss of Nfe2l1 attenuates pancreatic ß cells damage and dysfunction caused by STZ exposure, partially due to Nfe2l1 deficiency-induced metabolic switch to enhanced glycolysis.


Assuntos
Diabetes Mellitus Experimental , Células Secretoras de Insulina , Fator 1 Relacionado a NF-E2 , Animais , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/fisiologia , Masculino , Camundongos , Fator 1 Relacionado a NF-E2/genética , Fator 1 Relacionado a NF-E2/metabolismo , Estreptozocina
5.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(7): 824-827, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32788017

RESUMO

OBJECTIVE: To investigate the protective effect of insulin on burn serum-challenged cardiomyocytes in vitro. METHODS: Primary culture of cardiomyocytes from Sprague-Dawley (SD) 2-day-old neonate rats were divided into sham group, burn group, insulin group, and insulin activation inhibitor LY294002 pretreatment group (LY group). The model of cardiomyocytes injury induced by burn serum of 3-month-old SD rats [the serum of abdominal aortic was collected at 6 hours after modelling 30% total surface area (TBSA) III degree scald rat] was reproduced. In the insulin group, 10% burn serum and insulin (10 U/L) were added into cell culture medium, and in the LY group, LY294002 (50 µmol/L) was pretreated for 30 minutes before the addition of burn serum and insulin. Sham group was only given 10% serum of sham injured rats (sham rats were only placed in 37 centigrade warm water). After the cells were cultured for 12 hours, the release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and creatine kinase (CK) were determined by enzyme-linked immunosorbent assay (ELISA). The cardiac troponin T (cTnT) protein expression was examined by Western Blot. Apoptosis of cardiomyocytes was observed after Hoechst 33258 staining. RESULTS: Compared with the sham group, the cardiomyocytes were damaged and released inflammatory cytokines after burn serum-challenged. The levels of TNF-α, IL-6 and CK increased [TNF-α (ng/L): 273±48 vs. 21±6, IL-6 (ng/L): 416±83 vs. 44±11, CK (U/L): 1.44±0.24 vs. 0.14±0.08, all P < 0.01], while the expression of cTnT protein decreased (cTnT/ß-actin: 0.12±0.04 vs. 0.86±0.34, P < 0.01), and the cardiomyocyte apoptosis increased [(19.1±5.6)% vs. (5.2±1.3)%, P < 0.01]. Insulin could significantly reduce the damage of cardiomyocytes, decrease the release of TNF-α, IL-6 and CK induced by burn serum [TNF-α (ng/L): 105±37 vs. 273±48, IL-6 (ng/L): 176±77 vs. 416±83, CK (U/L): 0.82±0.26 vs. 1.44±0.24, all P < 0.05], the expression of cTnT protein significantly increased (cTnT/ß-actin: 0.41±0.16 vs. 0.12±0.04, P < 0.05), and the cells apoptosis rate significantly decreased [(10.7±3.2)% vs. (19.1±5.6)%, P < 0.05]. Further blocking experiments showed that LY294002 could mitigate the protective effects of insulin. CONCLUSIONS: For cardiomyocytes challenged by burn serum, insulin may decrease inflammation, apoptosis and then protect the cardiomyocytes.


Assuntos
Queimaduras , Insulina , Miócitos Cardíacos , Animais , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa
6.
ACS Appl Mater Interfaces ; 12(37): 41223-41229, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32830950

RESUMO

Converting CO2 into fuels and other value-added chemicals via an electrochemical reduction method has recently attracted great interest. However, there are still challenges to find suitable catalysts with high selectivity toward the formic acid formation. Here, we report the bimetallic CuSn-based catalyst to reduce CO2 to formic acid by optimizing the ratio of Cu to Sn to achieve the optimal selectivity. The catalyst is generated on laser-induced graphene. Among the catalysts, CuSn-4 with Cu/Sn atomic ratio close to 1:2 shows a faradaic efficiency of 99% toward formic acid with a high partial current density of 26 mA/cm2. Density functional theory calculations demonstrate that OCHO* intermediate formation is more favorable than that of COOH* on Sn sites, while OCHO* intermediate formation is moderate on Cu sites. The synergetic catalytic effect between Cu and Sn would further favor HCOOH formation. This study provides significant insight into the mechanism of formic acid formation.

7.
ACS Appl Mater Interfaces ; 12(30): 33795-33802, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32628446

RESUMO

Single-atom catalysts (SACs) with atomically dispersed metal sites in nitrogen-doped carbon matrices (M-N/C) have been identified as promising candidates for the electrocatalytic CO2 reduction reaction (CO2RR). However, recent studies aiming at economic viability have been inhibited by the low faradaic efficiency (FE) and instability under high current density. Herein, we report a series of SACs derived from cyano-substituted metal phthalocyanines (MePc-CN) in ZIFs (denoted as Me-SACs (Pc)). These phthalocyanine molecules enable the efficient construction of SACs, affording higher metal loading and less variation when compared with their counterparts from metal nitrates (denoted as Me-SACs (S)). Thus, Me-SACs (Pc) exhibit higher activities and selectivities than Me-SACs (S) in H-cell measurements. In gas-diffusion electrode (GDE) setups, the unstable Fe-SAC (Pc) shows only a 50% FE of CO (FEco) at -100 mA cm-2. In contrast, Ni-SAC (Pc) exhibits a higher FEco of >96% at current densities from -10 to -200 mA cm-2 and can stably operate for over 16 h at -200 mA cm-2. The performances of Ni-SAC (Pc) are comparable to those of precious metal catalysts and the best SACs reported so far, representing a promising candidate for practical electrolyzer devices for CO2RR.

8.
J Diabetes Investig ; 10(2): 446-457, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29923322

RESUMO

AIMS/INTRODUCTION: In the present meta-analysis, we aimed to determine the effects of sodium-glucose cotransporter 2 inhibitor (SGLT-2i) in addition to insulin therapy on cardiovascular risk factors in type 2 diabetes patients. MATERIALS AND METHODS: Randomized controlled trials were identified by searching the PubMed, Embase and Cochrane Library databases published before September 2017. The intervention group received SGLT-2i as add-on treatment to insulin therapy, and the control group received placebos in addition to insulin. We assessed pooled data, including weighted mean differences and 95% confidence intervals (CIs) using a random-effects model. RESULTS: A total of 10 randomized controlled trials (n = 5,159) were eligible. The weighted mean differences for systolic blood pressure and diastolic blood pressure were -3.17 mmHg (95% CI -4.53, -1.80, I2 = 0%) and -1.60 mmHg (95% CI -2.52, -0.69, I2 = 0%) in the intervention groups. Glycosylated hemoglobin, fasting plasma glucose, postprandial glucose and daily insulin were also lower in the intervention groups, with relative weighted mean differences of -0.49% (95% CI -0.71, -0.28%, I2 = 92%), -1.10 mmol/L (95% CI -1.69, -0.51 mmol/L, I2 = 84%), -3.63 mmol/L (95% CI -4.36, -2.89, I2 = 0%) and -5.42 IU/day (95% CI -8.12, -2.72, I2 = 93%). The transformations of uric acid and bodyweight were -26.16 µmol/L (95% CI -42.14, -10.17, I2 = 80%) and -2.13 kg (95% CI -2.66, -1.60, I2 = 83%). The relative risk of hypoglycemia was 1.09 (95% CI 1.02, 1.17, P < 0.01). The relative risks of urinary tract and genital infection were 1.29 (95% CI 1.03, 1.62, P = 0.03) and 5.25 (95% CI 3.55, 7.74, P < 0.01). CONCLUSIONS: The results showed that in the intervention group, greater reductions were achieved for blood pressure, glucose control, uric acid and bodyweight. This treatment regimen might therefore provide beneficial effects on the occurrence and development of cardiovascular events.


Assuntos
Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , China/epidemiologia , Quimioterapia Combinada , Humanos , Incidência , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
9.
Exp Ther Med ; 16(4): 3574-3578, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30233710

RESUMO

The effects of atrial fibrillation on complications and prognosis of patients receiving emergency percutaneous coronary intervention after acute myocardial infarction (AMI) were investigated. Eighty AMI patients treated with interventional vascular recanalization in the Affiliated Hospital of Weifang Medical University (Weifang, China) from July 2015 to October 2016 were selected, including 40 patients complicated with atrial fibrillation before operation (control group) and 40 patients without atrial fibrillation before operation (observation group). The systolic blood pressure, diastolic blood pressure, heart rate, arrhythmia and common complications after MI were compared. Changes in the coronary artery thrombolysis in myocardial infarction (TIMI) flow grade and left ventricular ejection fraction (LVEF) of patients were also recorded. Moreover, changes in brain natriuretic peptide (BNP) levels were compared. The recovery time of myocardial enzyme and total troponin in both groups was recorded. The systolic and diastolic blood pressure in the observation group were significantly higher than those in the control group (p<0.05). During the intervention, the total proportion of patients with ventricular arrhythmia, atrial arrhythmia, atrioventricular block and sinus tachycardia in the observation group was significantly lower than that in the control group (p<0.05). The total proportion of common complications after MI in the observation group was obviously lower than that in the control group (p<0.05). Coronary artery TIMI flow grades and LVEFs in the observation group were obviously higher than those in the control group. BNP levels in the observation group were significantly lower than those in the control group. The recovery time of myocardial enzyme and total troponin in the observation group was significantly earlier than that in the control group. Atrial fibrillation has a certain negative effect on the circulatory function in patients with AMI after the interventional therapy, and the proportions of arrhythmia and complications in patients after MI are increased at the same time, so the postoperative recovery of patients is slow with many complications.

10.
Mar Drugs ; 16(6)2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29874779

RESUMO

Postherpetic neuralgia (PHN) is nerve pain caused by a reactivation of the varicella zoster virus. Medications are used to reduce PHN but their use is limited by serious side effects. Tetrodotoxin (TTX) is a latent neurotoxin that can block neuropathic pain, but its therapeutic index is only 3⁻5 times with intravenous or intramuscular injection. Therefore, we prepared oral TTX pellets and examined their effect in a rat model of PHN induced by resiniferatoxin (RTX). Oral TTX pellets were significantly effective at preventing RTX-induced mechanical and thermal allodynia, and similar to pregabalin. Moreover, oral administration of TTX pellets dose-dependently inhibited RTX-induced PHN compared with intramuscular administration of TTX injection. We also studied the pharmacokinetic profile of TTX pellets. Our results showed that the blood concentration of TTX reached a maximum plasma concentration (Cmax) at around 2 h, with an elimination half-life time (t1/2) of 3.23 ± 1.74 h after intragastric administration. The median lethal dose (LD50) of TTX pellets was 517.43 µg/kg via oral administration to rats, while the median effective dose (ED50) was approximately 5.85 µg/kg, and the therapeutic index was 88.45. Altogether, this has indicated that oral TTX pellets greatly enhance safety when compared with TTX injection.


Assuntos
Implantes de Medicamento/farmacologia , Neuralgia Pós-Herpética/tratamento farmacológico , Tetrodotoxina/farmacologia , Animais , Diterpenos/farmacologia , Feminino , Hiperalgesia/tratamento farmacológico , Masculino , Neuralgia/tratamento farmacológico , Neurotoxinas/farmacologia , Ratos , Ratos Sprague-Dawley
11.
Chem Asian J ; 13(9): 1206-1212, 2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29543390

RESUMO

A multi-state and multi-stimuli-responsive oxazine molecular switch that combines an electro-base property and sensitive base/acid-responsive properties was designed and synthesized. The multi-state structures of the molecular switch, with different colors, were predicted by comparing the optical properties with reference molecules and confirmed by using NMR spectroscopy. The color-switching mechanism under stimulation with acids and bases was investigated by using DFT calculations. Three single states can be obtained and the switching is unidirectional under acid and base stimulation. The electrochromic phenomenon of the molecular switch, which combines its electro-base and base-sensitive properties, was demonstrated. An electrochromic device that exhibited good electrochromic properties with excellent reversibility (2000 cycles) and high coloration efficiency (804 cm2 C-1 ) was successfully constructed.

12.
Adv Mater ; 30(13): e1705948, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29430768

RESUMO

Circularly polarized light (CPL) is central to photonic technologies. A key challenge lies in developing a general route for generation of CPL with tailored chiroptical activity using low-cost raw materials suitable for scale-up. This study presents that cellulose films with photonic bandgaps (PBG) and left-handed helical sense have an intrinsic ability for circular polarization leading to PBG-based CPL with extraordinary |g | values, well-defiend handedness, and tailorable wavelength by the PBG change. Using such cellulose films, incident light ranging from near-UV to near-IR can be transformed to passive L-CPL and R-CPL with viewing-side-dependent handedness and |g | values up to 0.87, and spontaneous emission transformed to R-CPL emission with |g | values up to 0.68. Unprecedented evidence is presented with theoretical underpinning that the PBG effect can stimulate the R-CPL emission. The potential of cellulose-based CPL films for polarization-based encryption is illustrated. The evaporation-induced self-assembly coupled with nanoscale mesogens of cellulose nanocrystals opens new venues for technological advances and enables a versatile strategy for rational design and scalable manufacturing of organic and inorganic CPL films for photonic applications.

13.
RSC Adv ; 8(19): 10361-10366, 2018 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-35540482

RESUMO

Polymer nanocomposite fibers are important one-dimensional nanomaterials that hold promising potential in a broad range of technological applications. It is, however, challenging to organize advanced polymer nanocomposite fibers with sufficient mechanical properties and flexibility. Here, we demonstrate that strong, tough and flexible polymer nanocomposite fibers can be approached by electrospinning of a supramolecular ensemble of dissimilar and complementary components including flexible multiwalled carbon nanotubes (CNT), and stiff cellulose nanocrystals (CNC) in an aqueous poly(vinyl alcohol) (PVA) system. CNT and CNC are bridged by a water-soluble aggregation-induced-emission (AIE) molecule that forms π-π stacking with CNT via its conjugated chains, and electrostatic attraction with CNC through its positive charges leading to a soluble CNT-AIE-CNC ensemble, which further assembles with PVA through hydrogen bonds. A high level of ordering of the nanoscale building blocks combined with hydrogen bonding leads to a more efficient stress transfer path between the reinforcing unit and the polymer. The nanocomposite fiber mat is capable of selective detection of nitroaromatic explosives.

14.
Chemistry ; 24(12): 2980-2986, 2018 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-29282780

RESUMO

Higher-order organization of inorganic nanoparticles with hierarchical architectures and tailored functionality is crucial in the nanofabrication of advanced materials. Here we demonstrate that three-dimensional b-oriented MFI superstructures can be organized by synergistic chemical synthesis and self-assembly. The organization is accomplished by vapor treatment of tetrapropylammonium hydroxide (TPAOH)-coated inorganic/bacterial cellulose scaffolds. TPA+ acts to direct nucleation and to mediate crystal morphology leading to oriented assembly of MFI crystals along crystallographic b-axis, whereas bacterial cellulose holds the oriented assembly together forming three-dimensional superstructures with macroporosity. Self-supporting monoliths of the macroporous MFI show outstanding selective adsorption for para-xylene and high adsorption capacity for volatile organic compounds. Incorporating luminescent molecules imparts the macroporous monoliths the new property of adsorption tunable luminescence that may act as an optical sensor indicating the level of adsorption. The current work opens a novel space for rational organization of hierarchical materials with tailored architectures and multifunctionality.

15.
Endocr Relat Cancer ; 25(3): 185-200, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29203613

RESUMO

The transcription factor nuclear factor erythroid 2-like 1 (NFE2L1 or NRF1) is involved in various critical cell processes such as maintenance of ubiquitin-proteasome system and regulation of the cellular antioxidant response. We previously determined that pancreatic ß-cell-specific Nfe2l1-knockout mice had hyperinsulinemia and that silencing of Nfe2l1 in mouse islets or MIN6 insulinoma ß-cells induced elevated basal insulin release and altered glucose metabolism. Hypoglycemia is a major issue with aggressive insulinomas, although a role of NFE2L1 in this pathology is not defined. In the present work, we studied the tumorigenicity of Nfe2l1-deficient insulinoma MIN6 cells (Nfe2l1-KD) and sensitivity to chemotherapy. Nfe2l1-KD cells grew faster and were more aggressive than Scramble cells in vitro In a mouse allograft transplantation model, insulinomas arising from Nfe2l1-KD cells were more aggressive and chemoresistant. The conclusion was amplified using streptozotocin (STZ) administration in an allograft transplantation model in diabetic Akita background mice. Furthermore, Nfe2l1-KD cells were resistant to damage by the chemotherapeutic drugs STZ and 5-fluorouracil, which was linked to binding of hexokinase 1 with mitochondria, enhanced mitochondrial membrane potential and closed mitochondrial potential transition pore. Overall, both in vitro and in vivo data from Nfe2l1-KD insulinoma cells provided evidence of a previously un-appreciated action of NFE2L1 in suppression of tumorigenesis. Nfe2l1 silencing desensitizes insulinoma cells and derived tumors to chemotherapeutic-induced damage, likely via metabolic reprograming. These data indicate that NFE2L1 could potentially play an important role in the carcinogenic process and impact chemosensitivity, at least within a subset of pancreatic endocrine tumors.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Insulinoma , Fator 1 Relacionado a NF-E2/genética , Neoplasias Pancreáticas , Animais , Antineoplásicos/uso terapêutico , Apoptose , Linhagem Celular Tumoral , Fluoruracila/uso terapêutico , Inativação Gênica , Células Secretoras de Insulina/metabolismo , Insulinoma/tratamento farmacológico , Insulinoma/genética , Insulinoma/metabolismo , Insulinoma/patologia , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fator 1 Relacionado a NF-E2/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Estreptozocina/uso terapêutico
16.
Chem Commun (Camb) ; 53(81): 11209-11212, 2017 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-28956579

RESUMO

RGB color-tunable "turn-on" electrofluorochromic (EFC) devices with high color purity (457 nm for blue, 539 nm for green, and 641 nm for red), relatively quick response/fading speeds and remarkable fluorescence contrast ratios are successfully fabricated. They exhibit great potential for increasingly important multistage encrypted information storage and displays.

17.
ACS Appl Mater Interfaces ; 9(23): 20196-20204, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28535036

RESUMO

A biomimetic system on reversible bond-coupled electron transfer (BCET) has been proposed and investigated in a switchable Rh-N molecule with redox active subunits. We discover that energy barrier of C-N bond breaking is reduced dramatically to less than 1/7 (from 40.4 to 5.5 kcal/mol), and 1/3 of the oxidation potential is simultaneously lowered (from 0.67 to 0.43 V) with the oxidation of Rh-N. The concept, cation-coupled electron transfer (CCET), is highly recommended by analyzing existing proton coupled electron transfer (PCET) and metal coupled electron transfer (MCET) along with aforementioned BCET, which have same characteristic of transferring positive charges, such as proton, metal ion, and organic cation. Molecular switch can be controlled directly by electricity through BCET process. Solid electrochromic device was fabricated with extremely high coloration efficiency (720 cm2/C), great reversibility (no degradation for 600 cycles), and quick respond time (30 ms).

18.
J Diabetes Res ; 2016: 5294025, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27656657

RESUMO

Type 2 diabetes is a heterogeneous disorder that develops as a result of relatively inappropriate insulin secretion and insulin resistance. Increased levels of free fatty acids (FFAs) are one of the important factors for the pathogenesis of type 2 diabetes and contribute to defective ß-cell proliferation and increased ß-cell apoptosis. Recently, glucagon-like peptide-1 (GLP-1) receptor agonists have been shown to possess an antiapoptotic effect, by increasing ß-cell mass and improving ß-cell function. However, their effects on ß-cells in vitro against lipotoxicity have not been elucidated completely. In this study, we investigated whether the GLP-1 receptor agonist exendin-4 displays prosurvival effects in pancreatic ß-cells exposed to chronic elevated FFAs. Results showed that exendin-4 inhibited apoptosis induced by palmitate in MIN6 cells. After 24 h of incubation, exendin-4 caused rapid activation of extracellular signal-related kinase 1/2 (ERK1/2) under lipotoxic conditions. The ERK1/2 inhibitor PD98059 blocked the antilipotoxic effect of exendin-4 on MIN6 cells. Exendin-4 also inhibited the mitochondrial pathway of apoptosis. This inhibition is associated with upregulation of BCL-2. Our findings suggested that exendin-4 may exert cytoprotective effects through activation of ERK1/2 and inhibition of the mitochondrial apoptosis pathway.

19.
Sci Rep ; 6: 32714, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27600499

RESUMO

Liraglutide, a glucagon-like peptide (GLP-1) receptor agonist, has showed favorable effects in the glycaemic control and weight reduction in patients with type 2 diabetes mellitus (T2DM). The meta-analysis was to compare the efficacy and safety of liraglutide added to metformin with other treatments in patients with T2DM. A systematic literature search on PubMed, Embase, Web of Science and the Cochrane library databases were performed. Eligible studies were randomized controlled trials (RCTs) of patients with T2DM who received the combination treatment of liraglutide and metformin. Pooled estimates were performed using a fixed-effects model or random-effects model. A total of nine RCTs met the inclusion criteria. Compared with control (placebo, sitagliptin, glimepiride, dulaglutide, insulin glargine, and NPH), liraglutide in combination with metformin resulted in significant reductions in HbA1c, bodyweight, FPG, and PPG, and similar reductions in SBP, and DBP. Moreover, liraglutide combined with metformin did not increase the risk of hypoglycemia, but induced a higher incidence of gastrointestinal disorders. In conclusion, this meta-analysis confirmed the use of liraglutide as add-on to metformin appeared to be effective and safe for patients with T2DM. However, considering the potential limitations in this study, more large-scale, well-conducted RCTs are needed to identify our findings.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Liraglutida/administração & dosagem , Metformina/administração & dosagem , Quimioterapia Combinada , Hemoglobinas Glicadas/metabolismo , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
20.
Onco Targets Ther ; 9: 4763-71, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27536139

RESUMO

BACKGROUND: Efficient and targeted delivery of cytotoxic drugs is still a challenge in the fight against cancer. Ultrasound-targeted destruction of cytotoxic drug-loaded lipid microbubbles (LMs) might be a promising method. This study aimed to explore the antitumor effects of docetaxel-loaded LM (DLLM) combined with ultrasound-targeted microbubble destruction (UTMD) on liver cancer. MATERIALS AND METHODS: DLLMs were made by a mechanical vibration technique. The effects of docetaxel, DLLM alone, and DLLM + UTMD on cell viability and cell proliferation (Cell Counting Kit-8 assay) of MHCC-H cells and HepG2 cells were tested. The effects on cell cycle (flow cytometry) and apoptosis (flow cytometry and immunoblotting) of MHCC-H cells were tested. Solid fast-growing tumor mouse models were established and were randomized to blank LM + UTMD (controls) or DLLM + UTMD. Tumor volume was compared between the two groups. RESULTS: DLLMs had an 18%±7% drug-loading capacity, an 80%±3% encapsulation efficiency, and a mean particle size of 2,845 nm (75% range 1,527-5,534 nm). Compared to the other groups, DLLM + UTMD decreased the proliferation and increased the apoptosis of MHCC-H cells. DLLM + UTMD resulted in the inhibition of a higher proportion of cells in the G1 phase. Compared to the control group, the tumor volume in mice receiving DLLM + UTMD was smaller. CONCLUSION: DLLM + UTMD can increase the proportion of cells arrested in the G1 phase, decrease tumor cell proliferation, and induce MHCC-H cell apoptosis. The growth of solid tumors in mice was inhibited. These results could provide a novel targeted strategy against liver cancer.

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