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1.
Acc Chem Res ; 57(8): 1188-1201, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38578919

RESUMO

ConspectusCircularly polarized luminescence (CPL) generated by chiral luminescent systems has sparked enormous attention in multidisciplinary field as it brings infinite potential for applications, such as 3D optical displays, biological probes, and chiroptical sensors. Satisfying both the conditions of chirality and luminescence (including fluorescence or phosphorescence) is a prerequisite for constructing CPL materials. In this regard, whether in organic, inorganic, or hybrid systems, chiral and luminescent components generally involve effective coupling through covalent or noncovalent bonds. For covalent interactions, such as the copolymerization of chiral and luminescent monomers, although covalent bonds provide high stability for the system, they inevitably involve tedious preparation procedures that connect chirality and luminescence together. For noncovalent bonds, take supramolecular assembly as an example, chiral elements and achiral light-emitting units are chiral transferred through intermolecular interactions, and their advantages include the diversity of luminescent and chiral building blocks, the stimuli responsiveness brought by noncovalent bonds, as well as the potential amplification of CPL signals by coassembly. However, the stability of the assembly system may be poor, and the assembly chiroptical performance and morphology are difficult to predict. Gratifyingly, matching rule that do not rely on covalent together with noncovalent interactions allows for the effortless construction, modulation, as well as amplification of CPL systems.In this Account, we overview different strategies based on matching rule, including fluorescence-selective absorption, circularly polarized reflection, and circularly polarized fluorescence energy transfer (CPF-ET). Examples of these strategies are illustrated with a focus on helical polymers in light of their appealing structures and wide uses. For instance, for fluorescence-selective absorption, chiral helical polymers can convert racemic fluorescence light into a circularly polarized one with specific handedness by simply overlapping the helical polymer's circular dichroism (CD) spectra with the luminophore's emission spectra. For circularly polarized reflection, employing the selective reflection of certain handedness's circularly polarized light, the high helical twisting power (HTP) of the helical polymer in the cholesteric liquid crystals (N*-LCs) gives the system high glum. Additionally, for CPF-ET, only the emission spectrum of the donor and the absorption (or excitation) spectrum of the achiral acceptor are required to overlap, and no covalent or noncovalent interactions between the two are required. An outlook for the CPL materials related to matching rule which will avail the optimization and extension of this intriguing approach concludes the Account. We hope that the Account will offer insightful inspiration for the flourishing progress of chiroptical systems and present exciting opportunities.

2.
Pediatr Radiol ; 53(5): 920-928, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36976339

RESUMO

BACKGROUND: At present, there is a lack of normal magnetic resonance imaging (MRI) morphometric reference values for fetal internal jugular veins during middle and late pregnancy. OBJECTIVE: We used MRI to assess the morphology and cross-sectional area of the internal jugular veins of fetuses during middle and late pregnancy and to explore the clinical value of these parameters. MATERIALS AND METHODS: The MRI images of 126 fetuses in middle and late pregnancy were retrospectively analysed to determine the optimal sequence for imaging the internal jugular veins. Morphological observation of the fetal internal jugular veins in each gestational week was carried out, lumen cross-sectional area was measured and the relationship between these data and gestational age was analysed. RESULTS: The balanced steady-state free precession sequence was superior to other MRI sequences used for fetal imaging. The cross section of fetal internal jugular veins was predominantly circular in both the middle and late stages of pregnancy, however the prevalence of an oval cross section was significantly higher in the late gestational age group. The cross-sectional area of the lumen of the fetal internal jugular veins increased with increasing gestational age. Fetal jugular vein asymmetry was common, with the right jugular vein being dominant in the high gestational age group. CONCLUSION: We provide normal reference values for fetal internal jugular veins measured by MRI. These values may form the basis for clinical assessment of abnormal dilation or stenosis.


Assuntos
Feto , Veias Jugulares , Feminino , Gravidez , Humanos , Veias Jugulares/anatomia & histologia , Veias Jugulares/patologia , Estudos Retrospectivos , Valores de Referência , Imageamento por Ressonância Magnética
3.
Small ; 16(10): e1906775, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995284

RESUMO

Portable water splitting devices driven by rechargeable metal-air batteries or solar cells are promising, however, their scalable usages are still hindered by lack of suitable multifunctional electrocatalysts. Here, a highly efficient multifunctional electrocatalyst is demonstrated, i.e., 2D nanosheet array of Mo-doped NiCo2 O4 /Co5.47 N heterostructure deposited on nickel foam (Mo-NiCo2 O4 /Co5.47 N/NF). The successful doping of non-3d high-valence metal into a heterostructured nanosheet array, which is directly grown on a conductive substrate endows the resultant catalyst with balanced electronic structure, highly exposed active sites, and binder-free electrode architecture. As a result, the Mo-NiCo2 O4 /Co5.47 N/NF exhibits remarkable catalytic activity toward the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), affording high current densities of 50 mA cm-2 at low overpotentials of 310 mV for OER, and 170 mV for HER, respectively. Moreover, a low voltage of 1.56 V is achieved for the Mo-NiCo2 O4 /Co5.47 N/NF-based water splitting cell to reach 10 mA cm-2 . More importantly, a portable overall water splitting device is demonstrated through the integration of a water-splitting cell and two Zn-air batteries (open-circuit voltage of 1.43 V), which are all fabricated based on Mo-NiCo2 O4 /Co5.47 N/NF, demonstrating a low-cost way to generate fuel energy. This work offers an effective strategy to develop high-performance metal-doped heterostructured electrode.

4.
Langmuir ; 35(45): 14651-14658, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31625390

RESUMO

In this study, we demonstrate that Pt-Cu bimetallic nanoparticles with different compositions (Pt3Cu, PtCu, PtCu3) can be loaded in the lumen of halloysite nanotube (HNT) via a simple one-pot reduction. Increasing the pH of metallic precursor (H2PtCl6 and CuCl2)/HNT solutions enhances the dissociation of H2PtCl6, advancing the association of [PtCl6]2- with the positively charged inner surface (Al-OH) of HNT. Moreover, the shrinkage of bond length from Pt-Cl in [PtCl6]2- to Pt-O in [PtCl4(OH)2]2- due to pH-modulated ligand exchange may also assist Pt(IV) being trapped inside the halloysite. In the meantime, Cu(II) cations may complex with Pt(IV) anions via electrostatic force that would help the formation of Pt-Cu bimetallic nanoparticles inside the halloysite. The obtained PtCu3@HNT system shows a significantly enhanced catalytic performance in the reduction of 4-nitrophenol by sodium borohydride, with a mass activity approximating 60 times higher than that of unloaded Pt nanoparticles. The high catalytic efficiency can be maintained after thermal treatment at 200 or 400 °C.

5.
J BUON ; 23(1): 55-61, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29552760

RESUMO

PURPOSE: This study aimed to use propensity score matching (PSM) to compare the short- and long-term outcomes of laparoscopic surgery for the treatment of rectal cancer in elderly and middle-aged patients. METHODS: Data were retrospectively obtained from 588 patients aged ≥60 years when they underwent laparoscopic surgery for rectal cancer in our hospital between January 2009 and December 2016. The patients were divided into an elderly group (≥70 years) or a middle-aged group (60-69 years), and were subsequently matched 1:1 using PSM for sex, body mass index, Charlson comorbidity index (CCI), tumor location, clinical stage, and American Society of Anesthesiologists (ASA) score. A total of 115 patients from each group were matched and included in the study, and their short-term and long-term outcomes were compared. RESULTS: The elderly group had greater intraoperative blood loss and a higher surgical conversion rate, although the other outcomes were similar between the two groups (surgical time, pathology results, 30-day incidence of complications, and incidence of major complications). No patients died intraoperatively or within 30 days after surgery. There were no significant differences in the two groups' rates of tumor recurrence, 5-year overall survival, and 5-year disease-free survival. CONCLUSION: Although elderly patients had greater intraoperative blood loss and a higher surgical conversion rate, laparoscopic surgery for rectal cancer provided similar short-term and long-term outcomes among middle-aged and elderly patients.


Assuntos
Laparoscopia , Neoplasias Retais , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasias Retais/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
6.
Fish Shellfish Immunol ; 46(2): 252-60, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26159095

RESUMO

Anti-lipopolysaccharide factors (ALFs) are a group of antimicrobial peptides (AMPs) with broad-spectrum antimicrobial activities and antiviral activities mainly found in crustaceans and horseshoe crabs. In the present study, we identified 5 ALF expression sequence tags (ESTs) through analysis of the established M. nipponense transcriptome, and cloned their full-length cDNA sequences using rapid amplification of cDNA ends (RACE) method. The 5 ALFs were designated as MnALF1-5, and all of them showed high similarity with their Macrobrachium rosenbergii homologs in the phylogenetic analyses, especially in LPS binding domains. In healthy adult prawns, we found the highest expression of MnALF2 and MnALF4 in haemocytes, and the highest expression of MnALF4 and MnALF3 in intestine. Some isoforms of MnALF were down-regulated but the majority was up-regulated in different prawn tissues upon Aeromonas hydrophila challenge. To conform the expected antimicrobial activities harbored in MnALFs' LPS binding domains, we used a synthesized peptide cMnALF24 that corresponds to the LPS binding domain of MnALF2 as a representative molecule for the antibacterial activity test, and found that cMnALF24 possessed strong and broad-spectrum antibacterial activity against Gram positive and Gram negative bacteria, but no inhibition activity against fungi; Meanwhile, in the hemolytic test, cMnALF24 showed weak hemolysis activities (around 10%) to the rabbit red blood cells at concentrations of 0.67-33.50 µM. This study provides insights into understanding the antibacterial function of ALFs in the innate immunity of freshwater prawn, and reports a peptide that can be a potential drug candidate with good efficacy against bacterial infection and low toxicity to host cells.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/genética , Proteínas de Artrópodes/genética , Imunidade Inata , Lipopolissacarídeos/farmacologia , Palaemonidae/genética , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Sequência de Bases , China , Fungos/fisiologia , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , Dados de Sequência Molecular , Palaemonidae/metabolismo , Palaemonidae/microbiologia , Filogenia , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alinhamento de Sequência
7.
Nanoscale ; 16(14): 6853-6875, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38504609

RESUMO

Quantum dots (QDs) have emerged as fantastic luminescent nanomaterials with significant potential due to their unique photoluminescence properties. With the rapid development of circularly polarized luminescence (CPL) materials, many researchers have associated QDs with the CPL property, resulting in numerous novel CPL-active QD-containing materials in recent years. The present work reviews the latest advances in CPL-active QD-based materials, which are classified based on the types of QDs, including perovskite QDs, carbon dots, and colloidal semiconductor QDs. The applications of CPL-active QD-based materials in biological, optoelectronic, and anti-counterfeiting fields are also discussed. Additionally, the current challenges and future perspectives in this field are summarized. This review article is expected to stimulate more unprecedented achievements based on CPL-active QD-based materials, thus further promoting their future practical applications.

8.
IEEE Trans Cybern ; 54(1): 476-485, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37018109

RESUMO

In this article, the issue of event-triggered multiasynchronous H∞ control for Markov jump systems with transmission delay is concerned. In order to reduce sampling frequency, multiple event-triggered schemes (ETSs) are introduced. Then hidden Markov model (HMM) is employed to describe multiasynchronous jumps among subsystems, ETSs, and controller. Based on the HMM, the time-delay closed-loop model is constructed. In particular, when triggered data are transmitted over networks, a large transmission delay may cause disorder of transmission data such that the time-delay closed-loop model cannot be developed directly. To overcome this difficulty, a packet loss schedule is presented and the unified time-delay closed-loop system is obtained. By the use of the Lyapunov-Krasovskii functional method, sufficient conditions with the controller design are formulated for guaranteeing the H∞ performance of the time-delay closed-loop system. Finally, the effectiveness of the proposed control strategy is demonstrated by two numerical examples.

9.
J Acoust Soc Am ; 134(2): 1683-94, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23927209

RESUMO

High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in both thermal ablations for solid tumor/cancer and soft-tissue fragmentation. Mechanical and thermal effects, which play an important role in the HIFU treatment simultaneously, are dependent on the operating parameters and may vary with the progress of therapy. Mechanical erosion in the shape of a "squid," a "dumbbell" lesion with both mechanical and thermal lesions, or a "tadpole" lesion with mechanical erosion at the center and thermal necrosis on the boundary in the transparent gel phantom could be produced correspondingly with the pulse duration of 5-30 ms, which is much longer than histotripsy burst but shorter than the time for tissue boiling, and pulse repetition frequency (PRF) of 0.2-5 Hz. Meanwhile, variations of bubble cavitation (both inertial and stable cavitation) and temperature elevation in the focal region (i.e., z = -2.5, 0, and 2.5 mm) were measured by passive cavitation detection (PCD) and thermocouples during the therapeutic procedure, respectively. Stable cavitation increased with the pulse duration, PRF, and the number of pulses delivered. However, inertial cavitation was found to increase initially and then decrease with long pulse duration and high PRF. Temperature in the pre-focal region is always higher than those at the focal and post-focal position in all tests. Great variations of PCD signals and temperature elevation are due to the generation and persistence of large bubble, which is resistant to collapse and occurs with the increase of pulse duration and PRF. Similar lesion pattern and variations were also observed in ex vivo porcine kidneys. Hyperechoes in the B-mode ultrasound image were comparable to the shape and size of lesions in the dissected tissue. Thermal lesion volume increased with the increase of pulse duration and PRF, but mechanical erosion reached its maximum volume with the pulse duration of 20 ms and PRF of 1 Hz. Altogether, bubble cavitation and thermal field vary with the progress of HIFU treatment with different sonication parameters, which provide insights into the interaction of ultrasound burst with the induced bubbles for both soft tissue fractionation and enhancement in thermal accumulation. Appropriate synergy and monitoring of mechanical and thermal effects would broaden the HIFU application and enhance its efficiency as well as safety.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Temperatura Alta , Microbolhas , Som , Ultrassom/métodos , Animais , Rim/diagnóstico por imagem , Rim/cirurgia , Modelos Animais , Movimento (Física) , Sonicação , Termografia , Fatores de Tempo , Ultrassonografia
10.
IEEE Trans Neural Netw Learn Syst ; 34(3): 1502-1512, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34428162

RESUMO

This article is concerned with the neural network (NN)-based event-triggered control problem for discrete-time networked Markov jump systems with hybrid cyberattacks and unmeasured states. The event-triggered mechanism (ETM) is used to reduce the communication load, and a Luenberger observer is introduced to estimate the unmeasured states. Two kinds of cyberattacks, denial-of-service (DoS) attacks and deception attacks, are investigated due to the vulnerability of cyberlayer. For the sake of mitigating the impact of these two types of cyberattacks on system performance, the ETM under DoS jamming attacks is discussed first, and a new estimation of such mechanism is given. Then, the NN technique is applied to approximate the injected false information. Some sufficient conditions are derived to guarantee the boundedness of the closed-loop system, and the observer and controller gains are presented by solving a set of matrix inequalities. The effectiveness of the presented control method is demonstrated by a numerical example.

11.
IEEE Trans Cybern ; 53(2): 1170-1183, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34437088

RESUMO

This article investigates event-triggered and self-triggered L∞ control problems for the Markov jump stochastic nonlinear systems subject to denial-of-service (DoS) attacks. When attacks prevent system devices from obtaining valid information over networks, a new switched model with unstable subsystems is constructed to characterize the effect of DoS attacks. On the basis of the switched model, a multiple Lyapunov function method is utilized and a set of sufficient conditions incorporating the event-triggering scheme (ETS) and restriction of DoS attacks are provided to preserve L∞ performance. In particular, considering that ETS based on mathematical expectation is difficult to be implemented on a practical platform, a self-triggering scheme (STS) without mathematical expectation is presented. Meanwhile, to avoid the Zeno behavior resulted from general exogenous disturbance, a positive lower bound is fixed in STS in advance. In addition, the exponent parameters are designed in STS to reduce triggering frequency. Based on the STS, the mean-square asymptotical stability and almost sure exponential stability are both discussed when the system is in the absence of exogenous disturbance. Finally, two examples are given to substantiate the effectiveness of the proposed method.

12.
IEEE Trans Cybern ; 53(3): 1830-1842, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35077383

RESUMO

The neural-network (NN)-based state estimation issue of Markov jump systems (MJSs) subject to communication protocols and deception attacks is addressed in this article. For relieving communication burden and preventing possible data collisions, two types of scheduling protocols, namely: 1) the Round-Robin (RR) protocol and 2) weighted try-once-discard (WTOD) protocol, are applied, respectively, to coordinate the transmission sequence. In addition, considering that the communication channel may suffer from mode-dependent probabilistic deception attacks, a hidden Markov-like model is proposed to characterize the relationship between the malicious signal and system mode. Then, a novel adaptive neural state estimator is presented to reconstruct the system states. By taking the influence of deception attacks into performance analysis, sufficient conditions under two different scheduling protocols are derived, respectively, so as to ensure the ultimately boundedness of the estimate error. In the end, simulation results testify the correctness of the adaptive neural estimator design method proposed in this article.

13.
J Immunol ; 184(5): 2593-601, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-20097868

RESUMO

Recruitment of bone marrow-derived myelomonocytic cells plays a fundamental role in tumor angiogenesis and metastasis. Placental growth factor (PlGF) is a potent cytokine that can attract myelomonocytic cells to the tumor. However, the underlying mechanism remains obscure. In this study, we demonstrate that tumor-derived PlGF activates NFAT1 via vascular endothelial growth factor receptor 1 in both murine and human myelomonocytic cells. Activation of NFAT1 is crucial for PlGF-induced myelomonocytic cell recruitment as shown by the in vitro transwell migration assay, transendothelial migration assay, and PlGF-overexpressing tumor models in mice, respectively. TNF-alpha is upregulated by PlGF in myelomonocytic cells in an NFAT1-dependent manner, which in turn contributes to PlGF-induced myelomonocytic cell recruitment. Blockade of TNF-alpha expression by RNA interference or neutralization of secreted TNF-alpha with its Ab attenuates PlGF-induced myelomonocytic cell migration and transendothelial migration. Furthermore, the inhibitory effect of NFAT1 RNA interference on PlGF function is rescued by exogenously added TNF-alpha. Taken together, we demonstrate that NFAT1 mediates PlGF-induced myelomonocytic cell recruitment via the induction of TNF-alpha. Our present studies discover a novel role of the NFAT1-TNF-alpha pathway in tumor inflammation, which may provide potential targets to diversify current cancer therapy.


Assuntos
Monócitos/metabolismo , Células Mieloides/metabolismo , Fatores de Transcrição NFATC/metabolismo , Proteínas da Gravidez/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Ciclosporina/farmacologia , Imunofluorescência , Humanos , Immunoblotting , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/citologia , Células Mieloides/citologia , Fatores de Transcrição NFATC/antagonistas & inibidores , Fatores de Transcrição NFATC/genética , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Oligopeptídeos/farmacologia , Fator de Crescimento Placentário , Proteínas da Gravidez/genética , Interferência de RNA , Transfecção , Transplante Heterólogo , Fator de Necrose Tumoral alfa/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo
14.
IEEE Trans Cybern ; 52(10): 10240-10252, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33755575

RESUMO

In this article, the event-triggered resilient L∞ control problem is concerned for the Markov jump systems in the presence of denial-of-service (DoS) jamming attacks. First, a fixed lower bound-based event-triggering scheme (ETS) is presented in order to avoid the Zeno problem caused by exogenous disturbance. Second, when DoS jamming attacks are involved, the transmitted data are blocked and the old control input is kept by using the zero-order holder (ZOH). On the basis of this process, the effect of DoS attacks on ETS is further discussed. Next, by utilizing the state-feedback controller and multiple Lyapunov functions method, some criteria incorporating the restriction of DoS jamming attacks are proposed to guarantee the L∞ control performance of the event-triggered Markov closed-loop jump system. In particular, the bounded transition rates rather than the exact ones are taken into account. That is appropriate for the practical environment in which transition rates of the Markov process are difficult to measure accurately. Correspondingly, some criteria are proposed to obtain state-feedback gains and event-triggering parameters simultaneously. Finally, we provide two examples to show the effectiveness of the proposed method.

15.
ACS Nano ; 15(4): 7463-7471, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33724002

RESUMO

Chiral perovskites with circularly polarized luminescence (CPL) performance have attracted tremendous attention. This contribution reports a convenient and universal strategy for constructing chiral helical polymer/perovskite hybrid nanofibers with outstanding CPL properties. The hybrid nanofibers are prepared through a one-step electrospinning method in which chiral helical polyacetylenes, perovskite nanocrystals, and polyacrylonitrile serve as a handed-selective fluorescence filter, fluorescent source, and electrospinning matrix, respectively. Specially, perovskite nanocrystals are in situ formed during the electrospinning process, which avoids the tedious process for preparing and purifying perovskites. The prepared hybrid nanofibers all exhibit good long-time stability in air, owing to the effective protection effect of polymer matrix. More importantly, intense CPL emissions with high dissymmetry factor up to 10-2 level are obtained in the hybrid nanofibers. Furthermore, the emission color of CPL can be easily tuned by adjusting the precursors of perovskites. This work provides an efficient technique toward various kinds of CPL-active perovskite nanomaterials for both scientific research and future practical applications.

16.
J Mater Chem B ; 9(2): 373-380, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33283808

RESUMO

Applications in the harsh environment require hydrogels with ultra-stiffness, toughness, and stretchability. However, it remains a challenge to increase the elastic modulus without sacrificing the maximum elongation of hydrogels, because of the trade-off between stiffness and extensibility. Inspired by the crosslinking hierarchy of mussel byssus cuticle, here, we report a strategy to fabricate an ultra-stiff, tough and stretchable triple-crosslinked (TC) hydrogel. The polymer is crosslinked by chemical crosslinker at first, subsequently by introducing a polyphenolic compound, tannic acid (TA), and metal ions. The hydrogen-bond-based network between the polymer and TA works as an extensible and energy-dissipative network, mimicking the matrix of the cuticle, while the higher crosslinked domains formed by the coordinate bonds between TA and metal ions contribute to the stiffness. The triple-crosslinked hydrogel exhibits two orders of magnitude increase in stiffness (E = 58 MPa), but without sacrificing the maximum elongation (ε = 850%), compared with those of metal-free hydrogels (E = 0.18 MPa, and ε = 860%). The combination of ultra-stiffness, toughness, and stretchability in hydrogels is successfully achieved through leveraging the hierarchically cross-linked network based on hydrogen bonding and coordination bonding. Moreover, utilizing the wide distribution of bonding strength of coordination interaction, the mechanical properties of triple-crosslinked hydrogels can be manipulated by using different kinds of catechol-metal coordination.


Assuntos
Bivalves/química , Hidrogéis/química , Animais
17.
ChemSusChem ; 13(6): 1537-1545, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31797574

RESUMO

Aqueous zinc-ion batteries (ZIBs) have been considered as prospective alternatives for lithium-ion batteries, which are able to serve as power sources for next-generation wearable and flexible devices, owing to the merits of abundant zinc resources and high safety of aqueous electrolyte. However, the lack of suitable cathode materials with flexibility for ZIBs hinders their further application. Herein, a novel cathode material [i.e., MnO2 nanosheet-assembled hollow polyhedron anchored on carbon cloth (MnO2 /CC)] was prepared through a rapid hydrothermal method by using ZIF-67 as self-sacrificing template. When tested in an aqueous ZIB, the MnO2 /CC delivered a high reversible capacity of 263.9 mAh g-1 at 1.0 A g-1 after 300 cycles, far exceeding those of the commercial MnO2 electrode. More importantly, benefiting from the unique structural advantages, a flexible ZIB assembled based on the MnO2 /CC displayed a stable output voltage of 1.53 V and a specific capacity of 91.7 mAh g-1 at 0.1 A g-1 after 30 cycles. It also successfully lit LED bulbs even under different bending angles, showing good flexibility. This research contributes to the development of MnO2 -based cathode materials for high-performance flexible ZIBs.

18.
Clin Cancer Res ; 25(19): 5732-5734, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31366600

RESUMO

4-1BB (CD137) is an important costimulatory molecule upregulated on antigen-experienced T cells, however, clinical development of 4-1BB agonists has stalled because of significant liver immuno-toxicity. Using rational protein engineering, a next-generation anticalin-antibody-based therapy achieved localized 4-1BB activation triggered by tumor-expressed antigen, helping to revitalize this pathway in immuno-oncology.See related article by Hinner et al., p. 5878.


Assuntos
Neoplasias , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral , Humanos , Linfócitos T
19.
J Colloid Interface Sci ; 552: 351-358, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31132637

RESUMO

Metal organic frameworks (MOFs) derived carbon nanomaterial is among the most promising electrocatalysts as it has high surface area and plentiful doping elements. A further improvement in their performance is focusing on its diffusion-limited microporous nanostructure and the relatively poor graphitic degree. Herein, a novel 1D Co/N co-doped carbon nanomaterial (Co/N-CNT) with hierarchical micro- and mesoporous structure is prepared via epitaxial growth of ZIF-67 nanocrystals on polydopamine nanotubes (PDA NTs), followed by pyrolysis and acid leaching. Thanks to the inherent nature of PDA NTs, ZIF-67 nanocrystals were restrictedly grown on their surface homogeneously. After further treatment, the ZIF-67 derived Co/N doped carbon layers not only protect the integrity of 1D structure, but also exhibit "niches" like mesoporous structure to expose more active sites toward boosting oxygen reduction reaction. The rational designed Co/N-CNT composites have a comparable ORR activity to the commercial Pt/C catalyst, superior methanol tolerance and long-time durability in alkaline media, which may shed light on their further application toward energy conversion and storage.

20.
Nano Res ; 12(10): 2468-2476, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35966168

RESUMO

Oral drug delivery, which requires surviving the harsh environment in the gastrointestinal (GI) tract and penetrating the intestinal epithelium, has not been achieved using simple formulation nanoparticles (NPs). Medicinal natural products (MNPs) have been widely used in traditional medicine for disease management through oral consumption. However, most pharmacologically active compounds within MNPs do not have the properties suitable for oral applications. We hypothesize that some MNPs contain natural nanomaterials that can convert those compounds into oral formulations by forming NPs. After screening 66 MNPs, we identified five classes of small molecules that form NPs, many of which are capable of efficient drug encapsulation and GI penetration. We show that one of them, dehydrotrametenolic acid (DTA), is capable of mediating oral delivery for effective disease treatment. We determine that DTA NPs assemble through hydrogen bonding and penetrate the GI tract via apical sodium-dependent bile acid transporter. Our study reveals a novel class of single component, small molecule- assembled NPs for oral drug delivery, and suggests a novel approach to modernizing MNPs through nanomaterial discovery.

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