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1.
ACS Appl Mater Interfaces ; 16(34): 45166-45179, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39151129

RESUMO

In the pursuit of eco-friendly alternatives for refrigeration technology, electrocaloric materials have emerged as promising candidates for efficient solid-state refrigeration due to their high efficiency and integrability. However, current advancements in electrocaloric effects (ECEs) are often constrained by high temperatures and elevated electric fields (E-field), limiting practical applicability. Informed by phase-field simulation, this study introduces a (1-x)Pb(Yb1/2Nb1/2)O3-xPb(Mg1/3Nb2/3)O3 system, strategically engineered to incorporate highly ordered YN and disordered MN mixtures. The synergistic interplay between E-field/temperature-induced polarization reorientation and cation shift initiates multiple ferroelectric-antiferroelectric-paraelectric phase transitions. Our results demonstrate that under a moderate E-field of 50 kV cm-1, the x = 0.22 composition achieves remarkable performance with a giant temperature change (ΔT) of 3.48 K, a robust ECE strength (ΔT/ΔE) of 0.095 K cm kV-1, and a wide temperature span (Tspan) of 38 °C. Notably, the disrupted lattice structure contributes to ultralow electrostrains below 0.008%, with an average electrostrictive coefficient Q33 of 0.007 m4 C-2. The significantly weakened electrostrictive activity favors enhancing the performance stability of subsequent devices. This work introduces an innovative strategy for developing robust electrocaloric materials, offering substantial ΔT and low electrostrains, presenting promising advancements in ECE applications with an extended lifetime.

2.
Adv Mater ; : e2406219, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39135405

RESUMO

In pulse power systems, multilayer ceramic capacitors (MLCCs) encounter significant challenges due to the heightened loading electric field (E), which can lead to fatigue damage and ultrasonic concussion caused by electrostrictive strain. To address these issues, an innovative strategy focused on achieving an ultra-weak polarization-strain coupling effect is proposed, which effectively reduces strain in MLCCs. Remarkably, an ultra-low electrostrictive coefficient (Q33) of 0.012 m4 C-2 is achieved in the composition 0.55(Bi0.5Na0.5)TiO3-0.45Pb(Mg1/3Nb2/3)O3, resulting in a significantly reduced strain of 0.118% at 330 kV cm-1. At the atomic scale, the local structural heterogeneity leads to an expanded and loose lattice structure, providing ample space for large ionic displacement polarization instead of lattice stretching when subjected to the applied E. This unique behavior not only promotes energy storage performance (ESP) but also accounts for the observed ultra-low Q33 and strain. Consequently, the MLCC device exhibits an impressive energy storage density of 14.6 J cm-3 and an ultrahigh efficiency of 93% at 720 kV cm-1. Furthermore, the superior ESP of the MLCC demonstrates excellent fatigue resistance and temperature stability, making it a promising solution for practical applications. Overall, this pivotal strategy offers a cost-effective solution for state-of-the-art MLCCs with ultra-low strain-vibration in pulse power systems.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38605498

RESUMO

Lead-free relaxor ferroelectric ceramics with outstanding energy-storage (ES) density (Wrec) and high ES efficiency (η) are crucial for advanced pulse-power capacitors. This study introduces a strategic approach to maximizing the polarization difference (ΔP) by inducing a transition from the ferroelectric phase to the ergodic relaxor (ER) phase. By employing this strategy, a series of ceramics, (1 - x)(Bi0.5Na0.4K0.1)TiO3-x(Sr0.85La0.1)(Zr0.5Ti0.5)O3 (BNKT-xSLZT), with varying SLZT content (x = 0.05, 0.10, 0.15, and 0.20), were designed. The addition of SLZT enhances cationic disorder, induces vacancies at A sites, and disrupts long-range ferroelectric order, facilitating the formation of polar nanoregions and enhancing relaxor ferroelectric behavior. Furthermore, a viscous polymer process (VPP) technology is employed to optimize the ceramics' structure, aiming to increase the breakdown strength (Eb) and enhance ΔP. Ultimately, enhanced ES performance is demonstrated in BNKT-0.15SLZTVPP, achieving a remarkable Wrec of 6.85 J/cm3 and η of 84% under 470 kV/cm. This composition demonstrates excellent stability with minimal variations in Wrec (3.0%) and η (4.4%) over the temperature range of 20-110 °C. Additionally, BNKT-0.15SLZTVPP exhibits exceptional pulse charge-discharge properties, featuring a high discharge density of 3.72 J/cm3, a large power density of 164.2 MW/cm3, and a short discharge time (t0.9) of 193 ns under 300 kV/cm. The study validates the practicality of BNKT-0.15SLZTVPP for pulse capacitors and underscores the potential to enhance ES performance through A-site donor doping and VPP technology. This work provides a comprehensive understanding of the interplay among composition, structure, and ES properties in lead-free relaxor dielectric ceramics, laying the groundwork for innovative advancements in the field.

4.
Nanomicro Lett ; 16(1): 91, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38236335

RESUMO

The increasing awareness of environmental concerns has prompted a surge in the exploration of lead-free, high-power ceramic capacitors. Ongoing efforts to develop lead-free dielectric ceramics with exceptional energy-storage performance (ESP) have predominantly relied on multi-component composite strategies, often accomplished under ultrahigh electric fields. However, this approach poses challenges in insulation and system downsizing due to the necessary working voltage under such conditions. Despite extensive study, bulk ceramics of (Bi0.5Na0.5)TiO3 (BNT), a prominent lead-free dielectric ceramic family, have seldom achieved a recoverable energy-storage (ES) density (Wrec) exceeding 7 J cm-3. This study introduces a novel approach to attain ceramic capacitors with high ESP under moderate electric fields by regulating permittivity based on a linear dielectric model, enhancing insulation quality, and engineering domain structures through chemical formula optimization. The incorporation of SrTiO3 (ST) into the BNT matrix is revealed to reduce the dielectric constant, while the addition of Bi(Mg2/3Nb1/3)O3 (BMN) aids in maintaining polarization. Additionally, the study elucidates the methodology to achieve high ESP at moderate electric fields ranging from 300 to 500 kV cm-1. In our optimized composition, 0.5(Bi0.5Na0.4K0.1)TiO3-0.5(2/3ST-1/3BMN) (B-0.5SB) ceramics, we achieved a Wrec of 7.19 J cm-3 with an efficiency of 93.8% at 460 kV cm-1. Impressively, the B-0.5SB ceramics exhibit remarkable thermal stability between 30 and 140 °C under 365 kV cm-1, maintaining a Wrec exceeding 5 J cm-3. This study not only establishes the B-0.5SB ceramics as promising candidates for ES materials but also demonstrates the feasibility of optimizing ESP by modifying the dielectric constant under specific electric field conditions. Simultaneously, it provides valuable insights for the future design of ceramic capacitors with high ESP under constraints of limited electric field.

5.
ACS Appl Mater Interfaces ; 15(43): 50265-50274, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37871267

RESUMO

The electrostrictive effect, which induces strain in ferroelectric ceramics, offers distinct advantages over its piezoelectric counterpart for high-precision actuator applications, including anhysteretic behavior even at high frequencies, rapid reaction times, and no requirement for poling. Historically, commercially available electrostrictive materials have been lead oxide-based. However, global restrictions on the use of lead in electronic components necessitate the exploration of lead-free electrostrictive ceramics with a high strain performance. Although various engineering strategies for producing materials with high strain have been proposed, they typically come at the expense of increased strain hysteresis. Here, we describe the extraordinary electrostrictive response of (Ba0.95Ca0.05)(Ti0.88Sn0.12)O3 (BCTS) ceramics with ultrahigh electrostrictive strain and negligible hysteresis achieved through texture engineering leveraging the anisotropic intrinsic lattice contribution. The BCTS ceramics exhibit a high unipolar strain of 0.175%, a substantial electrostrictive coefficient Q33 of 0.0715 m4 C-2, and an ultralow hysteresis of less than 0.8%. Notably, the Q33 value is three times greater than that of high-performance lead-based Pb(Mg1/3Nb2/3)O3 electrostrictive ceramics. Multiscale structural analyses demonstrate that the electrostrictive effect dominates the BCTS strain response. This research introduces a novel approach to texture engineering to enhance the electrostrictive effect, offering a promising paradigm for future advancements in this field.

6.
Chemistry ; 29(51): e202301700, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37390122

RESUMO

Aerobic oxidative cross-coupling represents one of the most straightforward and atom-economic methods for construction of C-C and C-X (X=N, O, S, or P) bonds using air as a sustainable external oxidant. The oxidative coupling of C-H bonds in heterocyclic compounds can effectively increase their molecular complexity by introducing new functional groups through C-H bond activation, or by formation of new heterocyclic structures through cascade construction of two or more sequential chemical bonds. This is very useful as it can increase the potential applications of these structures in natural products, pharmaceuticals, agricultural chemicals, and functional materials. This is a representative overview of recent progress since 2010 on green oxidative coupling reactions of C-H bond using O2 or air as internal oxidant focus on Heterocycles. It aims to provide a platform for expanding the scope and utility of air as green oxidant, together with a brief discussion on research into the mechanisms behind it.

7.
Artigo em Inglês | MEDLINE | ID: mdl-37364018

RESUMO

Infectious aortic disease is a challenging life-threatening disease in cardiovascular surgery. A 70-year-old man patient presented with an infected infrarenal aortic pseudoaneurysm and right iliac artery- left iliac vein fistula (arteriovenous fistula). He underwent total infected tissues excision, debridement, in situ reconstructions of the aorta using a self-made pericardium graft with omental coverage and arteriovenous fistula patch repair to prevent leakage. One-year follow-up revealed the absence of clinically relevant infection with patency of the graft and the absence of biochemical inflammatory markers.

8.
Exp Mol Med ; 55(5): 939-951, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37121969

RESUMO

Neutrophil extracellular traps (NETs) play an important role in abdominal aortic aneurysm (AAA) formation; however, the underlying molecular mechanisms remain unclear. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) may exert therapeutic effects on AAA through their immunomodulatory and regenerative abilities. This study aimed to examine the role and mechanism of MSC-EVs in regulating the development of NET-mediated AAA. Excessive release of NETs was observed in patients with AAA, and the levels of NET components were associated with the clinical outcomes of the patients. Datasets from the Gene Expression Omnibus database were analyzed and revealed that the PI3K/AKT pathway and ferroptosis were strongly associated with NETosis during AAA formation. Further experiments verified that NETs promoted AAA formation by inducing ferroptosis in smooth muscle cells (SMCs) by inhibiting the PI3K/AKT pathway. The PI3K agonist 740 Y-P, the ferroptosis inhibitor ferrostatin-1, and Padi4 deficiency significantly prevented AAA formation. MSC-EVs attenuated AAA formation by reducing NET release in an angiotensin II-induced AAA mouse model. In vitro experiments revealed that MSC-EVs reduced the release of NETs by shifting NETosis to apoptosis. Our study indicates an important role for NET-induced SMC ferroptosis in AAA formation and provides several potential targets for AAA treatment.


Assuntos
Aneurisma da Aorta Abdominal , Armadilhas Extracelulares , Vesículas Extracelulares , Ferroptose , Células-Tronco Mesenquimais , Camundongos , Animais , Armadilhas Extracelulares/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Aneurisma da Aorta Abdominal/induzido quimicamente , Células-Tronco Mesenquimais/metabolismo , Vesículas Extracelulares/metabolismo , Miócitos de Músculo Liso/metabolismo , Modelos Animais de Doenças
9.
ACS Appl Mater Interfaces ; 15(5): 6990-7001, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36694407

RESUMO

Although relaxor ferroelectrics have been widely investigated owing to their various advantages, there are still impediments to boosting their energy-storage density (Wrec) and energy-storage efficiency (η). In this paper, we propose a cooperative optimization strategy for achieving comprehensive outstanding energy-storage performance in (Na0.5Bi0.5)0.7Sr0.3TiO3 (NBST)-based ceramics by triggering a nonergodic-to-ergodic transformation and optimizing the forming process. The first step of substituting NaNbO3 (NN) for NBST generated an ergodic state and induced polar nanoregions under the guidance of a phase-field simulation. The second step was to apply a viscous polymer process (VPP) to the 0.85NBST-0.15NN ceramics, which reduced porosity and increased compactness, resulting in a significant polarization difference and high breakdown strength. Consequently, 0.85NBST-0.15NN-VPP ceramics optimized by this cooperative two-step strategy possessed improved energy-storage characteristics (Wrec = 7.6 J/cm3, η = 90%) under 410 kV/cm as well as reliable temperature adaptability within a range of 20-120 °C, outperforming most reported (Na0.5Bi0.5) TiO3-based ceramics. The improved energy-storage performance validates the developed ceramics' practical applicability as well as the advantages of implementing a cooperative optimization technique to fabricate similar high-performance dielectric ceramics.

10.
Chemistry ; 29(5): e202202240, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36345123

RESUMO

Direct oxidative coupling of inert C(sp3 )-H bond has been a great challenge. Herein, an environmentally friendly aerobic oxidative coupling of α-methyl substituted N-heteroarenes with indoles is reported. A variety of diheteroaryl ketones were prepared in good yields (up to 72 %). This protocol features simple operation and broad substrates scope (26 examples). Significantly, a plausible mechanism about catalytic cycle was proposed, and two key intermediates were confirmed by high resolution mass spectrometry.


Assuntos
Indóis , Cetonas , Acoplamento Oxidativo , Indóis/química , Catálise
11.
Org Biomol Chem ; 20(29): 5845-5851, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35848391

RESUMO

A metal-free inactive C(sp3)-H bond functionalization of thioethers with styrenes using TBHP as an initiator and DBU as a base has been developed. This transformation has broken through the low activity of thioethers and realized moderate yields. Herein extended experiments were conducted to confirm the radical relay process, reaction energy and intermediate transformations.

12.
Front Cardiovasc Med ; 9: 847368, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35656393

RESUMO

Background: This study was performed to compare aortic remodeling and clinical outcomes in patients with acute, subacute, and chronic type B aortic dissection (TBAD) after thoracic endovascular aortic repair (TEVAR). Methods: We retrospectively examined 323 consecutive patients with acute (n = 129), subacute (n = 161), and chronic (n = 33) TBAD who underwent TEVAR from June 2013 to December 2016 in in multicenter institution. Patient demographics, clinical data, and imaging characteristics were recorded and compared among the three groups. Results: The three groups had comparable baseline characteristics. Perioperative mortality rates were similar among the acute (2.3%), subacute (0.0%), and chronic (0.0%) groups (P = 0.34). Perioperative morbidity rates, including the rates of visceral and lower limb malperfusion and cerebral infraction, were also similar. The rate of perioperative endoleak was significantly higher in the chronic group (18.1%) than in the acute (3.9%) and subacute (3.7%) groups (P = 0.02). The mean follow-up duration was 78 ± 22 months (range, 36-101 months). The mortality rates were comparable among the three groups. The rates of reintervention and lower limb malperfusion were higher in the chronic group than in the acute and subacute groups. FL diameter reduction were more robust in the acute and subacute groups than in the chronic group. Conclusion: Patients with acute, subacute, and chronic TBAD had different outcomes in this study. Patients with acute and subacute TBAD had fewer complications than those with chronic TBAD. Aortic remodeling after TEVAR was more favorable in patients with acute and subacute TBAD than in patients with chronic TBAD. TEVAR promotes more positive remodeling at the stent graft level than at the distal level of the aorta.

13.
Org Lett ; 24(2): 658-662, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-34968066

RESUMO

The synthesis of bioactive amides has been the pursuit of chemists. Herein secondary amides incorporated with an aldehyde group were first generated using aldehydes and secondary amines. Various (hetero)aryl aldehydes and even aliphatic aldehydes (>40 examples) were converted into the desired products in moderate to excellent yields (up to 89%). A plausible mechanism involving a Cu(I/II/III) catalytic cycle combined with radical rearrangement was proposed and confirmed with four key intermediates detected by high-resolution mass spectrometry.

14.
Front Cardiovasc Med ; 8: 783656, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970610

RESUMO

Objectives: The aim of this study was to present our experience with the management of isolated left vertebral artery (ILVA) during complex thoracic aortic pathology treated with the hybrid thoracic endovascular aortic repair. Methods: This is a single-center, respective cohort study. Between June 2016 and June 2020, 13 patients (12 men; median age 60 years old, range 42-72 years old) who underwent hybrid procedures were identified with ILVA in our center. Demographics, imaging features, operation details, and follow-up in these patients were collected and analyzed. Results: In this study, all patients received the hybrid procedure, and the primary technical success rate was 100%. There were no in-hospital deaths. Complication occurred in two (15.4%) patients. One patient suffered from contrast-induced acute kidney injury (CI-AKI) and recovered before discharge. Another patient required reintervention for acute left-lower-limb ischemia, which was successfully treated using Fogarty catheter embolectomy. Immediate vagus/recurrent laryngeal never palsy, lymphocele, and chylothorax were not observed. The median duration of follow-up was 22 months (range, 13-29 months). No neurologic deficits, bypass occlusion, or ILVA occlusion or stenosis were observed during the follow-up. No aortic rupture, cerebrovascular accident, or spinal cord ischemia was observed during the follow-up period. Conclusions: Our limited experience reveals that hybrid procedures [thoracic endovascular aortic repair (TEVAR), ILVA transposition, and left common carotid artery-left subclavian artery (LCCA-LSA) bypass] are relatively safe, feasible, and durable for the treatment of thoracic aortic pathology with ILVA. However, further technique durability and larger studies with long-term follow-up periods are warranted.

15.
J Cardiovasc Surg (Torino) ; 62(6): 582-590, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34338495

RESUMO

BACKGROUND: This study aimed to describe the outcomes of high-risk patients with symptomatic or impending ruptured pararenal aneurysm and thoraco-abdominal aortic aneurysm with comorbidities unsuitable for conventional open surgery, using physician-modified endografts (PMEGs). METHODS: A single-center retrospective analysis was conducted on 59 patients (mean age: 75 years; 47 males) treated with PMEGs between 2017 and 2020. Data on baseline characteristics, procedures, and clinical follow-up were collected to retrospectively analyze early (technical success, perioperative mortality, and major adverse events) and late (patency, endoleak, intervention, aneurysm thrombosis, and survival) outcomes. RESULTS: Technical success was achieved in 96.6% (57/59) of cases. The 30-day mortality rate was 5.1% (3/59). Five patients suffered renal failure and required temporary or permanent dialysis, one developed respiratory failure, and one suffered bowel ischemia. The major stroke rate was 3.4%, the spinal cord injury rate was 0%, and the myocardial infarction rate was 3.4%. During a mean follow-up period of 18.8±9.2 months, one patient suffered upper gastrointestinal bleeding and died after 7 postoperative months. Primary branch patency was observed in 97.2% of target vessels. Estimated freedom from reintervention was 88.1% and 87.5% at 6 months and 1 year, respectively. Five cases of endoleak (one type I, one type II, and three type III) were detected, and 7.1% required reintervention. The aneurysmal lumen thrombosis rate at 1 year was 89.6%. The estimated overall survival rate was 94.9% and 92.9% at 6 and 12 months, respectively. CONCLUSIONS: When used by experienced teams under appropriate anatomical conditions, PMEGs are a safe and effective alternative to open surgery. However, further technical advancement and larger studies with long-term follow-up periods are warranted.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/mortalidade , Aneurisma da Aorta Torácica/fisiopatologia , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , China , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Desenho de Prótese , Retratamento , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
16.
Oxid Med Cell Longev ; 2020: 3602824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32064021

RESUMO

Abdominal aortic aneurysm (AAA) is a vascular disorder that is considered a chronic inflammatory disease. However, the precise molecular mechanisms involved in AAA have not been fully elucidated. Recently, significant progress has been made in understanding the function and mechanism of action of inhibitor of kappa B kinase epsilon (IKKε) in inflammatory and metabolic diseases. The angiotensin II- (Ang II-) induced or pharmacological inhibitors were established to test the effects of IKKε on AAA in vivo. After mice were continuously stimulated with Ang II for 28 days, morphologically, we found that knockout of IKKε reduced AAA formation and drastically reduced maximal diameter and severity. We also observed a decrease in elastin degradation and medial destruction, which were independent of systolic blood pressure or plasma cholesterol concentrations. Western blot analyses and immunohistochemical staining were carried out to measure IKKε expression in AAA tissues and cell lines. AAA phenotype of mice was measured by ultrasound and biochemical indexes. In zymography, immunohistology staining, immunofluorescence staining, and reactive oxygen species (ROS) analysis, TUNEL assay was used to examine the effects of IKKε on AAA progression in AAA mice. IKKε deficiency significantly inhibited inflammatory macrophage infiltration, matrix metalloproteinase (MMP) activity, ROS production, and vascular smooth muscle cell (VSMC) apoptosis. We used primary mouse aortic VSMC isolated from apolipoprotein E (Apoe) -/- and Apoe-/-IKKε -/- mice. Mechanistically, IKKε deficiency blunted the activation of the ERK1/2 pathway. The IKKε inhibitor, amlexanox, has the same impact in AAA. Our results demonstrate a critical role of IKKε in AAA formation induced by Ang II in Apoe-/- mice. Targeting IKKε may constitute a novel therapeutic strategy to prevent AAA progression.


Assuntos
Angiotensina II/toxicidade , Aneurisma da Aorta Abdominal/metabolismo , Apoptose/genética , Quinase I-kappa B/deficiência , Inflamação/metabolismo , Estresse Oxidativo/genética , Idoso , Animais , Aneurisma da Aorta Abdominal/induzido quimicamente , Aneurisma da Aorta Abdominal/enzimologia , Aneurisma da Aorta Abdominal/fisiopatologia , Apolipoproteínas E/deficiência , Apoptose/efeitos dos fármacos , Elastina/metabolismo , Feminino , Humanos , Quinase I-kappa B/antagonistas & inibidores , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Inflamação/genética , Inflamação/patologia , Sistema de Sinalização das MAP Quinases/genética , Macrófagos/metabolismo , Masculino , Metaloproteinase 1 da Matriz/metabolismo , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação , Espécies Reativas de Oxigênio/metabolismo
17.
Biomater Sci ; 8(1): 353-369, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31724665

RESUMO

In spite of widespread applications of nano-photosensitizers, poor tumor penetration and severe hypoxia in the tumor microenvironment (TME) always result in an undesirable therapeutic outcome of photodynamic therapy (PDT). Herein, a biocompatible agarose-based hydrogel incorporated with sodium humate (SH), manganese oxide (MnO2) and chlorin e6 (Ce6) was synthesized as agarose@SH/MnO2/Ce6 through a "co-trapped" strategy during a sol-gel process and employed for combined photothermal therapy (PTT) and enhanced PDT. NIR-induced local hyperthermia is responsible for not only activating Ce6 release, but also triggering the catalytic decomposition of H2O2 mediated by MnO2 to relieve hypoxia. Such a hybrid hydrogel can realize deep tissue penetration through intratumoral injection, and exhibit remarkable tumor-site retention. Moreover, programmed laser irradiation led to an extremely high tumor growth inhibition rate of 93.8% in virtue of enhanced PTT/PDT. In addition, ultralow systemic toxicity caused by the hybrid hydrogel was further demonstrated in vivo. This reliable and eco-friendly hydrogel paves the way for the development of smart gel-based biomaterials, which respond to both exogenous and endogenous stimuli, towards the management of cancer and other major diseases.


Assuntos
Substâncias Húmicas/análise , Hidrogéis/química , Raios Infravermelhos , Compostos de Manganês/química , Nanopartículas/química , Neoplasias/tratamento farmacológico , Óxidos/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Clorofilídeos , Liberação Controlada de Fármacos/efeitos da radiação , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas/química , Porfirinas/metabolismo , Porfirinas/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Transplante Homólogo , Hipóxia Tumoral/efeitos dos fármacos
18.
Org Lett ; 21(18): 7450-7454, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31508970

RESUMO

Rare-earth catalysis has become a hot topic in the field of catalytic organic reaction. Chain ethers mostly have lower reactivity and lower boiling points which limited their reaction scope. Herein, we found a rare-earth Y(OTf)3 can catalyze the coupling reaction of ethers especially chain ethers and thioethers with azaarenes. This protocol features simple operations, a broad substrate scope (31 examples), moderate to good yields (up to 85%), and atom economy.

19.
ACS Biomater Sci Eng ; 4(12): 4266-4277, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33418824

RESUMO

The injection of theranostic drug-laden hydrogels into subcutaneous tumors has proven to be a promising strategy to achieve precise local tumor eradication. Humic acid, a natural product of biochemical decomposition of animal and plant residues, abundantly exists in soils, peats, oceans, etc. In this study, a robust injectable thermoresponsive agarose hydrogel incorporating sodium humate (SH) and doxorubicin (DOX) was constructed as a unique agent for tumor management based on the combined chemo-photothermal therapeutic effect. SH, which strongly absorbs near-infrared (NIR) light, can efficiently convert light energy into thermal energy, induce local hyperthermia and subsequently trigger sustained drug release from the complex of the SH/DOX@hydrogel through a typical gel-sol transition, resulting in enhanced cellular uptake of therapeutic drugs. Moreover, intratumoral injection of the SH/DOX@hydrogel resulted in a simultaneous chemo-photothermal therapeutic effect against solid tumors under NIR laser irradiation, which may collectively prevent tumor recurrence. In addition, the SH/DOX@hydrogel exhibited ultralow systemic toxicity as demonstrated using an animal model. This work provides a promising attempt to develop a low-cost, light-responsive hydrogel for precise tumor therapy, which may also incorporate extra theranostic modules as an advanced platform for the treatment of cancer or other critical diseases.

20.
Curr Neurovasc Res ; 13(1): 45-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26666638

RESUMO

In patients with severe carotid artery stenosis, the effects of carotid artery reopening, achieved either by carotid endarterectomy (CEA) or carotid artery stenting (CAS), on cognitive functions remain elusive. Herein, we conducted a prospective study to determine whether and to what extent CEA and CAS affected cognitive performance. Patients admitted to the Department of Neurology or Vascular Surgery in Nanjing First Hospital from December 2012 to March 2015 with a diagnosis of severe carotid artery stenosis (>70%) were included in the study. Among them, 77 patients underwent CEA, 81 patients underwent CAS, and 77 patients who refused to receive aforementioned interventions were enrolled in control group. Of note, all patients in this study received basic pharmacological treatment according to the American Heart Association/American Stroke Association guidelines. Cognitive functions were evaluated by a broad spectrum of neuropsychological tests including the Mini-mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) and event related potential P300 on the day prior to and at 3 months after indicated intervention. When compared with basic pharmacological treatment, both CEA and CAS significantly increased the scores of MMSE and MoCA at 3 months following procedures. Meanwhile, a significant reduction of P300 score was also observed in patients underwent CEA or CAS. In addition, the changes in MMSE, MoCA and P300 scores over time between CEA and CAS groups were not statistically significant. Taken together, our findings suggest an improvement of cognitive functions following carotid artery reopening. Meanwhile, the beneficial effects of CEA and CAS on cognitive performance seem to be equivalent.


Assuntos
Estenose das Carótidas , Transtornos Cognitivos , Stents Farmacológicos , Endarterectomia das Carótidas , Idoso , Estenose das Carótidas/complicações , Estenose das Carótidas/tratamento farmacológico , Estenose das Carótidas/cirurgia , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/cirurgia , Eletroencefalografia , Potenciais Evocados P300/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Retrospectivos , Estatísticas não Paramétricas , Resultado do Tratamento
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