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1.
Angew Chem Int Ed Engl ; 63(17): e202400758, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38450854

RESUMO

Designing materials capable of adapting their mechanical properties in response to external stimuli is the key to preventing failure and extending their service life. However, existing mechanically adaptive polymers are hindered by limitations such as inadequate load-bearing capacity, difficulty in achieving reversible changes, high cost, and a lack of multiple responsiveness. Herein, we address these challenges using dynamic coordination bonds. A new type of mechanically adaptive material with both rate- and temperature-responsiveness was developed. Owing to the stimuli-responsiveness of the coordination equilibria, the prepared polymers, PBMBD-Fe and PBMBD-Co, exhibit mechanically adaptive properties, including temperature-sensitive strength modulation and rate-dependent impact hardening. Benefitting from the dynamic nature of the coordination bonds, the polymers exhibited impressive energy dissipation, damping capacity (loss factors of 1.15 and 2.09 at 1.0 Hz), self-healing, and 3D printing abilities, offering durable and customizable impact resistance and protective performance. The development of impact-resistant materials with comprehensive properties has potential applications in the sustainable and intelligent protection fields.

2.
Angew Chem Int Ed Engl ; 63(32): e202407277, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38780892

RESUMO

Chiral multi-resonance thermally activated delayed fluorescence (CP-MR-TADF) materials hold promise for circularly polarized organic light-emitting diodes (CP-OLEDs) and 3D displays. Herein, we present two pairs of tetraborated intrinsically axial CP-MR-TADF materials, R/S-BDBF-BOH and R/S-BDBT-BOH, with conjugation-extended bidibenzo[b,d]furan and bidibenzo[b,d]thiophene as chiral sources, which effectively participate in the distribution of the frontier molecular orbitals. Due to the heavy-atom effect, sulfur atoms are introduced to accelerate the reverse intersystem crossing process and increase the efficiency of molecules. R/S-BDBF-BOH and R/S-BDBT-BOH manifest ultra-pure blue emission with a maximum at 458/459 nm with a full width at half maximum of 27 nm, photoluminescence quantum yields of 90 %/91 %, and dissymmetry factors (|gPL|) of 6.8×10-4/8.5×10-4, respectively. Correspondingly, the CP-OLEDs exhibit good performances with an external quantum efficiency of 30.1 % and |gEL| factors of 1.2×10-3.

3.
Angew Chem Int Ed Engl ; 62(22): e202301993, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36995342

RESUMO

Room-temperature phosphorescence (RTP) polymers, whose emission can persist for a long period after photoexcitation, are of great importance for practical applications. Herein, dynamic covalent boronic ester linkages with internal B-N coordination are incorporated into a commercial epoxy matrix. The reversible dissociation of B-N bonds upon loading provides an efficient energy dissipation pathway for the epoxy network, while the rigid epoxy matrix can inhibit the quenching of triplet excitons in boronic esters. The obtained polymers exhibit enhanced mechanical toughness (12.26 MJ m-3 ), ultralong RTP (τ=540.4 ms), and shape memory behavior. Notably, there is no apparent decrease in the RTP property upon prolonged immersion in various solvents because the networks are robust. Moreover, the dynamic bonds endow the polymers with superior reprocessablity and recyclability. These novel properties have led to their potential application for information encryption and anti-counterfeiting.

4.
Angew Chem Int Ed Engl ; 62(48): e202313728, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37818673

RESUMO

Information security has gained increasing attention in the past decade, leading to the development of advanced materials for anti-counterfeiting, encryption and instantaneous information display. However, it remains challenging to achieve high information security with simple encryption procedures and low-energy stimuli. Herein, a series of strain/temperature-responsive liquid crystal elastomers (LCEs) are developed to achieve dual-modal, multi-level information encryption and real-time, rewritable transient information display. The as-prepared polydomain LCEs can change from an opaque state to a transparent state under strain or temperature stimuli, with the transition strains or temperatures highly dependent on the concentration of long-chain flexible spacers. Information encrypted by different LCE inks can be decrypted under specific strains or temperatures, leading to multi-level protection of information security. Furthermore, with the combination of the phase transition of polydomain LCEs and the photothermal effect of multi-walled carbon nanotubes (MWCNTs), we achieved a repeatable transient information display by using near-infrared (NIR) light as a pen for writing. This study provides new insight into the development of advanced encryption materials with versatility and high security for broad applications.

5.
Angew Chem Int Ed Engl ; 62(27): e202304183, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37154674

RESUMO

Modulation of the ligands and coordination environment of metal-organic frameworks (MOFs) has been an effective and relatively unexplored avenue for improving the anode performance of lithium-ion batteries (LIBs). In this study, three MOFs are synthesized, namely, M4 (o-TTFOB)(bpm)2 (H2 O)2 (where M is Mn, Zn, and Cd; o-H8 TTFOB is ortho-tetrathiafulvalene octabenzoate; and bpm is 2,2'-bipyrimidine), based on a new ligand o-H8 TTFOB with two adjacent carboxylates on one phenyl, which allows us to establish the impact of metal coordination on the performance of these MOFs as anode materials in LIBs. Mn-o-TTFOB and Zn-o-TTFOB, with two more uncoordinated oxygen atoms from o-TTFOB8- , show higher reversible specific capacities of 1249 mAh g-1 and 1288 mAh g-1 under 200 mA g-1 after full activation. In contrast, Cd-o-TTFOB shows a reversible capacity of 448 mAh g-1 under the same condition due to the lack of uncoordinated oxygen atoms. Crystal structure analysis, cyclic voltammetry measurements of the half-cell configurations, and density functional theory calculations have been performed to explain the lithium storage mechanism, diffusion kinetics, and structure-function relationship. This study demonstrates the advantages of MOFs with high designability in the fabrication of LIBs.

6.
Arch Virol ; 167(12): 2519-2528, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36083350

RESUMO

The wide spread of coronavirus disease 2019 (COVID-19) has significantly threatened public health. Human herd immunity induced by vaccination is essential to fight the epidemic. Therefore, highly immunogenic and safe vaccines are necessary to control SARS-CoV-2, whose S protein is the antigenic determinant responsible for eliciting antibodies that prevent viral entry and fusion. In this study, we developed a SARS-CoV-2 DNA vaccine expressing the S protein, named pVAX-S-OP, which was optimized according to the human-origin codon preference and using polyinosinic-polycytidylic acid as an adjuvant. pVAX-S-OP induced specific antibodies and neutralizing antibodies in BALB/c and hACE2 transgenic mice. Furthermore, we observed 1.43-fold higher antibody titers in mice receiving pVAX-S-OP plus adjuvant than in those receiving pVAX-S-OP alone. Interferon gamma production in the pVAX-S-OP-immunized group was 1.58 times (CD3+CD4+IFN-gamma+) and 2.29 times (CD3+CD8+IFN-gamma+) lower than that in the pVAX-S-OP plus adjuvant group but higher than that in the control group. The pVAX-S-OP vaccine was also observed to stimulate a Th1-type immune response. When, hACE2 transgenic mice were challenged with SARS-CoV-2, qPCR detection of N and E genes showed that the viral RNA loads in pVAX-S-OP-immunized mice lung tissues were 104 times and 106 times lower than those of the PBS control group, which shows that the vaccine could reduce the amount of live virus in the lungs of hACE2 mice. In addition, pathological sections showed less lung damage in the pVAX-S-OP-immunized group. Taken together, our results demonstrated that pVAX-S-OP has significant immunogenicity, which provides support for developing SARS-CoV-2 DNA candidate vaccines.


Assuntos
COVID-19 , Vacinas de DNA , Animais , Humanos , Camundongos , Adjuvantes Imunológicos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Imunidade Celular , Camundongos Transgênicos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Vacinas de DNA/genética
7.
Microb Pathog ; 150: 104729, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33429053

RESUMO

The Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) cause a huge economic loss around the pig industry worldwide; the NADC30-like PRRSV have attracted much attention outbreaks in China in recent years. Recombination between PRRSV subtypes, point mutations, insertions and deletions that contribute to the emergence of new variants in the genome. In this study, the PRRSV-HB-16-China-2019 strain's full-length genomic sequence shares 93.0% nucleotide similarity to NADC30 PRRSV without any gene insertion. Compared with VR-2332, it has an NSP2 coding region that is different from NADC30, which has a discontinuous 206-aa (111-aa from position 323 to 433 and 95-aa from position 476 to 570) deletion. Compared with other NADC30-Like strains, it has a discontinuous 75-amino acid (75-aa from position 476 to 552) deletion, which was first reported. Notably, the strain, PRRSV-HB-16-China-2019, contained an addition a 1-aa deletion in ORF5 and a unique 3-nt deletion in 3'-UTR similar to NADC30, the strain is recombined between a NADC30-like strain and a vaccine strain named RespPRRS MLV(parental strain VR-2332). Our findings indicate that PRRSV-HB-16-China-2019 is a new NSP2-deletion NADC30-like strain with certain deletions and mutations. Our results show that the emergence of the new NADC30-like strain has increased the difficulty of PRRSV prevention in China.


Assuntos
Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Animais , China , Variação Genética , Genoma Viral , Filogenia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Recombinação Genética , Suínos
8.
Molecules ; 25(3)2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32019143

RESUMO

The design of polymers that exhibit both good elasticity and self-healing properties is a highly challenging task. In spite of this, the literature reports highly stretchable self-healing polymers, but most of them exhibit slow elastic recovery behavior, i.e., they can only recover to their original length upon relaxation for a long time after stretching. Herein, a self-healing polymer with a fast elastic recovery property is demonstrated. We used 4-[tris(4-formylphenyl)methyl]benzaldehyde (TFPM) as a tetratopic linker to crosslink a poly(dimethylsiloxane) backbone, and obtained a self-healing polymer with high stretchability and fast elastic recovery upon stretching. The strain at break of the as-prepared polymer is observed at about 1400%. The polymer can immediately recover to its original length after being stretched. The damaged sample can be healed at room temperature with a healing efficiency up to 93% within 1 h. Such a polymer can be used for various applications, such as functioning as substrates or matrixes in soft actuators, electronic skins, biochips, and biosensors with prolonged lifetimes.


Assuntos
Reagentes de Ligações Cruzadas/química , Dimetilpolisiloxanos/química , Elasticidade , Polímeros/química , Estrutura Molecular , Temperatura
9.
Molecules ; 24(18)2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31487954

RESUMO

Dual-functional polymeric system combining shape memory with self-healing properties has attracted increasingly interests of researchers, as both of these properties are intelligent and promising characteristics. Moreover, shape memory polymer that functions at human body temperature (37 °C) are desirable because of their potential applications in biomedical field. Herein, we designed a polymer network with a permanent covalent crosslinking and abundant weak hydrogen bonds. The former introduces elasticity responsible and maintain the permanent shape, and the latter contributes to the temporary shape via network rearrangement. The obtained PDMS-COO-E polymer films exhibit excellent mechanical properties and the capability to efficiently self-heal for 6 h at room temperature. Furthermore, the samples turn from a viscous state into an elastic state at 37 °C. Therefore, this polymer has shape memory effects triggered by body temperature. This unique material will have a wide range of applications in many fields, containing wearable electronics, biomedical devices, and 4D printing.


Assuntos
Materiais Biocompatíveis/química , Polímeros/química , Materiais Inteligentes/química , Dimetilpolisiloxanos/química , Ligação de Hidrogênio , Análise Espectral , Temperatura
10.
Inorg Chem ; 57(6): 3232-3242, 2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29481073

RESUMO

Coordination bonds are effective for constructing highly efficient self-healing materials as their strength is highly tunable. To design self-healing polymers with better performance, it is important to get a profound understanding of the structure-property relationships. However, this is challenging for self-healing polymers based on coordination bonds, because many parameters, such as bond energy, bond dynamics, and coordination number will have an essential effect on the mechanical and self-healing properties of the polymer. In this work, we synthesized two poly(dimethylsiloxane) (PDMS) polymers cross-linked by different Zn(II)-diiminopyridine coordination complexes (denoted as PDMS-NNN-Zn, PDMS-MeNNN-Zn respectively). The two cross-linking Zn(II)-diiminopyridine complexes are similar in coordination modes, but differ in coordination dynamics. As manifested by ITC, rheology, and tensile experiments, we confirm that the coordination bond in PDMS-MeNNN-Zn polymer films is weaker but more dynamic. Consequently, the PDMS-MeNNN-Zn polymer has poorer mechanical strength but higher stretchability and better self-healing properties. The inflicted cracks on PDMS-MeNNN-Zn polymer films can be completely healed after healing at room temperature for only 30 min with healing efficiencies higher than 90%. Such fast self-healing properties have never been achieved in self-healing polymers based on coordination bonds. Our results also demonstrate the important impact of the thermodynamic stability and kinetic lability of coordination complexes on the mechanical and self-healing properties of polymers. Such a comprehensive understanding is helpful for further design of novel synthetic polymers, which can achieve an optimal balance between the mechanical strength and self-healing performance.

11.
Angew Chem Int Ed Engl ; 57(47): 15384-15389, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30251399

RESUMO

A series of dibenzo[a,f][1,3,5]triazino[2,1,6-cd] pyrrolizine compounds have been synthesized from phthalonitriles by a facile intramolecular cyclization process using "half-phthalocyanine" precursors, and they were characterized by X-ray crystallography, 1 H NMR spectroscopy, UV/Vis, and theoretical calculations. These compounds have spectroscopic profiles similar to phthalocyanines and porphyrins, although their inner-core structures and coordination types are totally different. They can be regarded as a new class of aromatic fused-ring compounds. The low-energy absorption of these new fused-ring compounds are located at around 600 nm. Such a low-energy π-π* transition is scarce in aromatic compounds having a similar molecular size. According to the nomenclature of phthalocyanines, these types of compounds have been named phthalorubines (Prs).

12.
Macromol Rapid Commun ; 37(12): 952-6, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27126099

RESUMO

Combining stretchability and self-healing properties in a man-made material is a challenging task. For an efficient self-healing material, weaker dynamic or reversible bonds should be presented as crosslinks so that they will first break upon damage and then reform after healing, which is not favorable when developing elastic materials. In this work, by incorporating dynamic Fe(III)-triazole coordination bonds into polydimethylsiloxane (PDMS) backbone, a highly elastic polymer is obtained that can be thermally healed at mild temperature. The as-prepared polymer can be stretched to 3400% strain at low loading speed (1 mm min(-1) ). When damaged, the polymer can be thermally healed at 60 °C for 20 h with a healing efficiency of over 90%. The good mechanical and healable properties of this polymer can be ascribed to the unique coordination bond strength and coordination conformation of Fe(III)-triazole coordination complex.


Assuntos
Dimetilpolisiloxanos/química , Temperatura , Compostos Férricos/química , Estrutura Molecular
13.
Macromol Rapid Commun ; 37(20): 1667-1675, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27569252

RESUMO

A new self-healing polymer has been obtained by incorporating a cyclometalated platinum(II) complex Pt(C∧ N∧ N)Cl (C∧ N∧ N = 6-phenyl-2,2'-bipyridyl) into a polydimethylsiloxane (PDMS) backbone. The molecular interactions (a combination of Pt···Pt and π-π interactions) between cyclometalated platinum(II) complexes are strong enough to crosslink the linear PDMS polymer chains into an elastic film. The as prepared polymer can be stretched to over 20 times of its original length. When damaged, the polymer can be healed at room temperature without any healants or external stimuli. Moreover, the self-healing is insensitive to surface aging. This work represents the first example where the attractive metallophilic inter-actions are utilized to design self-healing materials. Moreover, our results suggest that the stretchability and self-healing properties can be obtained simultaneously without any conflict by optimizing the strength of crosslinking interactions.


Assuntos
Compostos Organoplatínicos/química , Polímeros/química , Microscopia de Força Atômica , Polímeros/síntese química
14.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 38(2): 131-5, 2016 Apr.
Artigo em Zh | MEDLINE | ID: mdl-27181886

RESUMO

OBJECTIVE: To compare the effectiveness of high-frequency jet ventilation via Wei jet nasal airway and controlled ventilation with improved laryngeal mask airway during bronchial thermoplasty. METHODS: Twenty-eight patients undergoing bronchial thermoplasty were equally divided into two groups: group A (high-frequency jet ventilation through Wei jet nasal airway) and group B (controlled ventilation with improved laryngeal mask airway). Pulse oxygenation,heart rate,and mean arterial blood pressure were recorded after entering the operating room (T0), 1 minute after administration/induction (T1), bronchoscope inserting (T2), 15 minutes (T3)/30 minutes (T4)/45 minutes (T5) after ventilation,at the end of the operation (T6), and at the recovery of patients' consciousness (T7). The pH,arterial oxygen partial pressure,and arterial carbon dioxide partial pressure were recorded at T0, T4, and T6. The endoscope indwelling duration,operative time,patients' awakening time,adverse events during anesthesia,satisfactions of patients and operators, anesthesic effectiveness were also recorded. RESULTS: The arterial carbon dioxide partial pressur in group A at T4 and T6 were significantly higher than in group B (P<0.05). The pH in group A at T4 and T6 was significantly lower than in group B (P<0.05). The endoscope indwelling duration and the operative time in group B were significantly shorter than in group A (P<0.05) while the recovery of consciousness in group B was significantly longer than in group A (P<0.05). The satisfaction for operators and the efficacy of anesthesia in group B were better than in group A (P<0.05). The number of adverse events in group B was significantly smaller than in group A (P<0.05). CONCLUSION: The improved laryngeal mask airway with controlled ventilation is more suitable for bronchial thermoplasty.


Assuntos
Broncoscopia , Ablação por Cateter , Ventilação em Jatos de Alta Frequência/instrumentação , Máscaras Laríngeas , Gasometria , Frequência Cardíaca , Humanos
15.
Inorg Chem ; 54(1): 143-52, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25495433

RESUMO

A series of chiral cyclometalated platinum(II) complexes, [Pt((-)-L1)(Dmpi)]Cl ((-)-1), [Pt((+)-L1)(Dmpi)]Cl ((+)-1), [Pt((-)-L2)(Dmpi)]Cl ((-)-2), [Pt((+)-L2)(Dmpi)]Cl ((+)-2), [Pt3((-)-L2)2(Dmpi)4](ClO4)4 ((-)-3), and [Pt3((+)-L2)2(Dmpi)4](ClO4)4 ((+)-3) [(-)-L1 = (-)-4,5-pinene-6'-phenyl-2,2'-bipyridine, (+)-L1 = (+)-4,5-pinene-6'-phenyl-2,2'-bipyridine), (-)-L2 = (-)-1,3-bis(2-(4,5-pinene)pyridyl)benzene, (+)-L2 = (+)-1,3-bis(2-(4,5-pinene)pyridyl)benzene, Dmpi = 2,6-dimethylphenyl isocyanide], have been designed and synthesized. In aqueous solutions, (-)-1 and (+)-1 aggregate into one-dimensional helical chain structures through Pt···Pt, π-π, and hydrophobic-hydrophobic interactions. (-)-3 and (+)-3 represent a novel helical structure with Pt-Pt bonds. The formation of helical structures results in enhanced and distinct chiroptical properties as evidenced by circular dichroism spectra. Circularly polarized luminescence (CPL) was observed from the aggregates of (-)-1 and (+)-1 in water, as well as (-)-3 and (+)-3 in dichloromethane. The CPL activity can be switched reversibly (for (-)-1 and (+)-1) or irreversibly (for (-)-3 and (+)-3) by varying the temperature.


Assuntos
Derivados de Benzeno/química , Complexos de Coordenação/química , Compostos Organoplatínicos/química , Piridinas/química , Complexos de Coordenação/síntese química , Cristalografia por Raios X , Luminescência , Medições Luminescentes , Metanol , Cloreto de Metileno , Conformação Molecular , Compostos Organoplatínicos/síntese química , Solventes , Estereoisomerismo , Temperatura , Água
16.
Angew Chem Int Ed Engl ; 54(31): 9070-4, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26110590

RESUMO

Novel aza-diisoindolylmethene and their BF2 -chelating complexes (benzo-fused aza-BODIPYs) were synthesized on a large scale and in a facile manner from phthalonitrile in tBuOK-DMF solution. The unique asymmetric donor-π-acceptor structure facilitates B-N bond detachment in the presence of trifluoroacetic acid (TFA) in dichloromethane, resulting in sharp color change from red to colorless, with over 250 nm hypsochromic shift in the absorption maximum. This colorimetric process can be reversed by adding a very small amount of proton-accepting solvents or compounds. A (1) H and (11) B NMR spectroscopy study and also density functional theory (DFT) calculations suggest that TFA-induced B-N bond cleavage may disrupt the whole π-conjugation of the BODIPY molecule, resulting in significant colorimetric behavior.

17.
Small Methods ; : e2301705, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530062

RESUMO

Polymer materials formed by conventional metal-ligand bonds have very low branch functionality, the crosslinker of such polymer usually consists of 2-4 polymer chains and a single metal ion. Thus, these materials are weak, soft, humidity-sensitive, and unable to withstand their shape under long-term service. In this work, a new hyperbranched metal-organic cluster (MOC) crosslinker containing up to 16 vinyl groups is prepared by a straightforward coordination reaction. Compared with the current typical synthesis of metal-organic cages (MOCs) or metal-organic-polyhedra (MOP) crosslinkers with complex operations and low yield, the preparation of the MOC is simple and gram-scale. Thus, MOC can serve as a high-connectivity crosslinker to construct hyper-crosslinked polymer networks. The as-prepared elastomer exhibits mechanical robustness, creep-resistance, and humidity-stability. Besides, the elastomer possesses self-healing and recyclability at mild condition as well as fluorescence stability. These impressive comprehensive properties are proven to originate from the hyper-crosslinked topological structure and microphase-separated morphology. The MOC-driven hyper-crosslinked elastomers provide a new solution for the construction of mechanically robust, durable, and multifunctional polymers.

18.
Nanomicro Lett ; 16(1): 122, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372850

RESUMO

Compared with traditional piezoelectric ultrasonic devices, optoacoustic devices have unique advantages such as a simple preparation process, anti-electromagnetic interference, and wireless long-distance power supply. However, current optoacoustic devices remain limited due to a low damage threshold and energy conversion efficiency, which seriously hinder their widespread applications. In this study, using a self-healing polydimethylsiloxane (PDMS, Fe-Hpdca-PDMS) and carbon nanotube composite, a flexible optoacoustic patch is developed, which possesses the self-healing capability at room temperature, and can even recover from damage induced by cutting or laser irradiation. Moreover, this patch can generate high-intensity ultrasound (> 25 MPa) without the focusing structure. The laser damage threshold is greater than 183.44 mJ cm-2, and the optoacoustic energy conversion efficiency reaches a major achievement at 10.66 × 10-3, compared with other carbon-based nanomaterials and PDMS composites. This patch is also been successfully examined in the application of acoustic flow, thrombolysis, and wireless energy harvesting. All findings in this study provides new insight into designing and fabricating of novel ultrasound devices for biomedical applications.

19.
Chirality ; 25(7): 384-92, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23740554

RESUMO

Two couples of enantiomeric platinum(II) complexes: Pt(L1a )Cl (1a), Pt(L1b )Cl (1b) and Pt(L1a )(C ≡ C - Ph) (2a), Pt(L1b )(C ≡ C - Ph) (2b) (L1a = (+)-1,3-di-(2-(4,5-pinene)pyridyl)benzene, L1b = (-)-1,3-di-(2-(4,5-pinene)pyridyl)benzene) were synthesized and characterized. Their absolute configurations were determined by single crystal X-ray diffraction and further verified by circular dichroism (CD) spectra (including electronic circular dichroism [ECD] and vibrational circular dichroism [VCD]). These complexes show interesting mechanoluminescence and/or vapoluminescence due to crystalline-to-amorphous transformation. The crystalline solids, grinding-induced amorphous powders, and vapor-induced amorphous powders of complexes 2a and 2b were comparatively investigated by solid-state ECD and VCD spectra. The transformation from crystalline solids to amorphous powders was accompanied by significant variances of the spectral feature in both ECD and VCD spectra.

20.
Zhonghua Yi Xue Za Zhi ; 93(13): 1023-7, 2013 Apr 02.
Artigo em Zh | MEDLINE | ID: mdl-23886270

RESUMO

OBJECTIVE: To investigate the effects of platelet on intercellular adhesion between leukocyte and liver sinusoidal endothelial cell(LSEC) and the transendothelial migration under the hypoxia-reoxygenation condition, as well as the role of relevant adhesion molecules. METHOD: LSEC was cultured for 24 hours under hypoxia condition and then reoxygenated for 2 hours (hypoxia-reoxygenation, HR). This hypoxia-reoxygenation model was used to simulate the clinical liver ischemia-reperfusion injury process (IRI). Platelets and leukocytes were labeled with fluorescence dye, and then the adhesion was detected by fluorescence microscope, fluorescence plate reader and laser scanning confocal microscope. Antibody blockage experiment was used to analyze the relevant adhesion molecules. RESULTS: The adhesion between platelets and LSEC was increased significantly after HR. The fluorescence intensity of adherent platelets increased from 142.10 ± 7.53 to 289.17 ± 20.00(P < 0.01). After H-R treatment and the addition of platelets, the number of adherent leukocytes increased markedly, and a significant statistical difference (360.71 ± 23.47 and 186.39 ± 17.96, P < 0.01) was found in comparing with the platelet deficient group. These adhesion processes could be blocked respectively by anti-GPIb, anti-GPIIb, anti-GPIIIa, anti-P-selectin, anti-CD31, anti-ICAM-1, anti-VCAM-1 and anti-ELAM-1. Confocal microscopy showed that platelets located between leukocytes and LSEC, and mediated their adhesion process. However, the adhesion of platelets to LSEC decreased the transendothelial migration of leukocytes (227.79 ± 16.51 and 167.27 ± 10.92, P < 0.05). CONCLUSION: During ischemia-reperfusion condition platelets adhere to the surface of LSEC, and then further mediate more adhesion processes between leukocytes and endothelial cells, as well as inhibit the transendothelial migration of leukocytes. The consequence is that large numbers of leukocytes were sequestrated within hepatic sinus, and deteriorate liver ischemia-reperfusion injury.


Assuntos
Plaquetas/citologia , Adesão Celular , Células Endoteliais/citologia , Leucócitos/citologia , Traumatismo por Reperfusão , Migração Transendotelial e Transepitelial , Hipóxia Celular , Células Cultivadas , Endotélio Vascular/citologia , Veias Hepáticas/citologia , Humanos , Oxigênio/metabolismo
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