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1.
Brief Bioinform ; 23(1)2022 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-34953465

RESUMEN

Alzheimer's disease (AD) has a strong genetic predisposition. However, its risk genes remain incompletely identified. We developed an Alzheimer's brain gene network-based approach to predict AD-associated genes by leveraging the functional pattern of known AD-associated genes. Our constructed network outperformed existing networks in predicting AD genes. We then systematically validated the predictions using independent genetic, transcriptomic, proteomic data, neuropathological and clinical data. First, top-ranked genes were enriched in AD-associated pathways. Second, using external gene expression data from the Mount Sinai Brain Bank study, we found that the top-ranked genes were significantly associated with neuropathological and clinical traits, including the Consortium to Establish a Registry for Alzheimer's Disease score, Braak stage score and clinical dementia rating. The analysis of Alzheimer's brain single-cell RNA-seq data revealed cell-type-specific association of predicted genes with early pathology of AD. Third, by interrogating proteomic data in the Religious Orders Study and Memory and Aging Project and Baltimore Longitudinal Study of Aging studies, we observed a significant association of protein expression level with cognitive function and AD clinical severity. The network, method and predictions could become a valuable resource to advance the identification of risk genes for AD.


Asunto(s)
Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Redes Reguladoras de Genes , Predisposición Genética a la Enfermedad , Envejecimiento/genética , Perfilación de la Expresión Génica , Humanos , Estudios Longitudinales , Memoria , Proteómica , RNA-Seq , Transcriptoma
2.
Inorg Chem ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38976574

RESUMEN

Traditional information encryption materials that rely on fluorescent/phosphorescent molecules are facing an increasing risk of counterfeiting or tampering due to their static reading mode and advances in counterfeiting technology. In this study, a series of Mg2-xZnxSnO4 (x = 0.55, 0.6, 0.65, 0.7 0.75, 0.8) that realizes the writing, reading, and erasing of dynamic information is developed. When heated to 90 °C, the materials exhibit a variety of dynamic emission changes with the concentration of Zn2+ ions. As the doping concentration increased, the ratio of the shallow trap to deep trap changed from 7.77 to 20.86. When x = 0.55, the proportion of deep traps is relatively large, resulting in a higher temperature and longer time required to read the information. When x = 0.80, the proportion of shallow traps is larger and the encrypted information is easier to read. Based on the above features, encryption binary codes device was designed, displaying dynamic writing, reading, and erasing of information under daylight and heating conditions. Accordingly, this work provides reliable guidance on advanced dynamic information encryption.

3.
Inorg Chem ; 63(8): 3921-3930, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38335732

RESUMEN

Metal-organic frameworks (MOFs) with multifunctional and tunable optical properties have unique advantages in the field of sensing, and the structure and properties of MOFs are significantly influenced by the ligands. In this study, a Y-type tricarboxylic acid ligand containing amide bonds was synthesized through functional guidance, and three isomorphic and heterogeneous three-dimensional MOFs (Eu-MOF, Tb-MOF, and Gd-MOF) were obtained by solvothermal reaction. Further studies revealed that both the Tb-MOF and Eu-MOF could selectively detect picric acid (PA). The luminescence quenching of the two MOFs by PA was attributed to competing absorption and photoelectron energy transfer mechanisms. In addition, due to the energy transfer between Tb and Rhodamine B, Rhodamine B was encapsulated into Tb-MOF. The obtained material exhibited a linear relationship between the temperature parameters I544/I584 and temperature within the range of 280-400 K, the correlation coefficient (R2) reached an impressive value of 0.999, and the absolute sensitivity of the sample used for temperature sensing was 1.534% K-1. What is more, the material exhibited a good response to trifluoroacetic acid vapor, which suggests the potential of the material for temperature sensing and detection of trifluoroacetic acid vapor. The designed and investigated strategy can also serve as a reference for further research on excellent multifunctional sensors.

4.
Inorg Chem ; 63(4): 1725-1735, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38225216

RESUMEN

NaH2SIP was selected as an organic ligand (NaH2SIP = 5-sulfoisophthalic acid monosodium salt). We successfully constructed a new class of lanthanide coordination polymers Ln-HS ([Ln(SIP)(DMF)(H2O)4]DMF·H2O; Ln = Eu, Tb, Sm, and Dy) by a simple solvothermal synthesis method. They exhibited excellent photoluminescence properties for Ln3+ ions, where Eu-HS and Tb-HS exhibited high quantum yields of 13.70 and 42.38%, respectively. The codoped lanthanide coordination polymers obtained by doping with different ratios of Eu3+/Tb3+ serve as excellent ratiometric thermometers with high sensitivities in the physiological temperature range, with values of 16.8, 7.0, and 14.5%·K-1, respectively. The luminescent colors of Tb0.95Eu0.05-HS and Tb0.94Eu0.06-HS exhibit variations from green to yellow to orange, achieving visualized luminescence in a narrow temperature range. The composite film material Tb0.94Eu0.06-HS@PMMA demonstrates this color variation. Next, Tb0.5Sm0.5-HS obtained by Tb3+/Sm3+ codoping was investigated. The difference in the luminescence colors visible to the naked eye at different excitation wavelengths and the change in luminescence colors occur in a very narrow temperature range. All of them show the great value of the visualized luminescence in practical anticounterfeiting, with double anticounterfeiting function and high security.

5.
Inorg Chem ; 63(14): 6192-6201, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38518256

RESUMEN

Fe2O3 is a promising semiconductor for photoelectrochemical (PEC) water decomposition. However, severe charge recombination problems limit its applications. In this study, a F-Fe2O3-x/MoS2 nanorod array photoanode was designed and prepared to facilitate charge separation. Detailed characterization and experimental results showed that F doping in Fe2O3 regulated the electronic structure to improve the conductivity of Fe2O3 and induced abundant oxygen vacancies to increase the carrier concentration and promote charge separation in bulk. In addition, the internal electric field between F-Fe2O3-x and MoS2 facilitated the qualitative transfer of the photogenerated charge, thus inhibiting their recombination. The synergistic effect between the oxygen vacancy and F-Fe2O3-x/MoS2 heterojunction significantly enhanced the PEC performance of Fe2O3. This study provides a universal strategy for designing other photoanode materials with high-efficiency charge separation.

6.
Anal Chem ; 95(2): 1376-1384, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36562538

RESUMEN

As a momentous gas signal molecule, sulfur dioxide (SO2) participates in diverse physiological activities. Excess SO2 will cause an apparent decrease in the level of intracellular glutathione (GSH), thereby damaging the body's antioxidant defense system. In addition, endogenous SO2 can be generated from GSH by reacting with thiosulfate (S2O32-) and enzymatically reduced to cysteine (Cys), a synthetic precursor of GSH. In view of their close correlation, a two-photon (TP) mitochondria-targeted multifunctional fluorescence sensor Mito-Na-BP was rationally designed and synthesized for detecting SO2 and GSH simultaneously. Under single-wavelength excitation, the sensor responded to GSH-SO2 and SO2-GSH continuously with blue-shifted and green fluorescence-enhanced signal modes, respectively, not just to GSH (enhanced) and SO2 (quenched) at 638 nm with a completely converse response tendency. Given its favorable spectral performance (high sensitivity, superior selectivity, and fast response rate) at physiological pH, Mito-Na-BP has been successfully applied in monitoring the level fluctuation of GSH affected from high-dose SO2 and visualizing in real time the metabolic process of GSH to SO2 by TP imaging. It is expected that this research will provide a convenient and efficient tool for elucidating intricate relationships of GSH and SO2 and facilitate further exploration of their functions in biomedicine.


Asunto(s)
Diagnóstico por Imagen , Dióxido de Azufre , Humanos , Fluorescencia , Dióxido de Azufre/química , Glutatión/metabolismo , Colorantes Fluorescentes/química , Células HeLa
7.
Inorg Chem ; 62(25): 9781-9791, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37307418

RESUMEN

Lanthanide luminescent MOF materials show excellent luminescent properties. However, obtaining lanthanide luminescent MOFs with high quantum yield is a challenging research. A novel bismuth-based metal-organic framework [Bi(SIP)(DMF)2] was constructed by solvothermal method, utilizing 5-sulfoisophthalic acid monosodium salt (NaH2SIP) and Bi(NO3)3·5H2O. Thereafter, doped MOFs (Ln-Bi-SIP, Ln = Eu, Tb, Sm, Dy, Yb, Nd, Er) with different luminescent properties have been obtained by in situ doping with different lanthanide metal ions, among which Eu-Bi-SIP, Tb-Bi-SIP, Sm-Bi-SIP, and Dy-Bi-SIP have high quantum yield. What is special is that the doping amount of Ln3+ ions is very low, and the doped MOF can achieve high luminescence quantum yields. EuTb-Bi-SIP obtained by Eu3+/Tb3+ codoping and Dy-Bi-SIP exhibit good temperature sensing performance over a wide temperature range with the maximum sensitivity Sr of 1.6%·K-1 (433 K) and 2.6%·K-1, respectively (133 K), while the cycling experiments also show good repeatability in the assay temperature range. Finally, considering the practical application value, EuTb-Bi-SIP was blended with an organic polymer poly(methyl methacrylate) (PMMA) to produce a thin film, which shows different color changes at different temperatures.

8.
Inorg Chem ; 62(1): 75-86, 2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36574356

RESUMEN

The continuously growing significance of information security and authentication has put forward many new requirements and challenges for modern luminescent materials and anti-counterfeiting technologies. Recently, luminescent materials have attracted much attention in this field owing to their legibility, repeatability, multicolor, and multiple stimuli-responsive nature. In this work, the efficient multicolor and multimodal luminescence material CaCd2Ga2Ge3O12:Mn2+ was successfully designed and synthesized using the strategy of single-doped Mn2+ in a single matrix. Also, we combined the morphology, crystal structure, energy band calculation, luminescence properties, and trap analysis to study the optical data storage capacity of CaCd2Ga2Ge3O12:Mn2+. Interestingly, in the presence of the 254 nm UV lamp, the sample can exhibit a tunable emission color from bule to cyan to yellow by increasing the dopant concentration of Mn2+. Also, under the afterglow and thermoluminescence luminescence modes, it presented strong yellow emission centered at 558 nm. Based on the advantage of multiple tunable luminescence, samples were made into anti-counterfeiting ink and were used to print four optical devices through the screen printing technology. The results show that the material has excellent multicolor anti-counterfeiting properties under the three luminescence modes, which has contributed to the development of many kinds of luminescent anti-counterfeiting materials for security purposes.


Asunto(s)
Luminiscencia , Humanos , Manganeso , Germanio , Cadmio , Calcio
9.
Inorg Chem ; 62(46): 19015-19024, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37919966

RESUMEN

Highly efficient transformation of carbon dioxide (CO2) into value-added chemicals is considered a promising route for clean production and future energy sustainability, which is crucial for realizing a carbon-neutral economy. It remains a great challenge to develop highly stable and active catalysts with low-cost, environmentally friendly, and nontoxic materials for catalytic conversion of CO2. Herein, a precious-metal-free and heterogeneous MOF (LTG-FeZr) catalyst, composed of bis(terpyridine)iron(II) complexes and zirconium(IV) ions, was designed and prepared via a metalloligand approach. LTG-FeZr, with a robust framework and regular 1D channels not only can achieve the photocatalytic reduction of CO2 to HCOOH with a high conversion rate (up to 265 µmol·g-1·h-1) under visible-light irradiation but also exhibits exceptional catalytic activities toward the synthesis of cyclic carbonates via cycloaddition reactions of various epoxides and CO2 in the absence of light. Possible mechanisms for two different conversion processes of CO2 catalyzed by LTG-FeZr have been proposed. LTG-FeZr represents an ideal dual-function MOF platform for the catalytic conversion and utilization of CO2 in all weather conditions.

10.
Sensors (Basel) ; 23(6)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36991632

RESUMEN

Research has shown that when a microcontroller (MCU) is powered up, the emitted electromagnetic radiation (EMR) patterns are different depending on the executed instructions. This becomes a security concern for embedded systems or the Internet of Things. Currently, the accuracy of EMR pattern recognition is low. Thus, a better understanding of such issues should be conducted. In this paper, a new platform is proposed to improve EMR measurement and pattern recognition. The improvements include more seamless hardware and software interaction, higher automation control, higher sampling rate, and fewer positional displacement alignments. This new platform improves the performance of previously proposed architecture and methodology and only focuses on the platform part improvements, while the other parts remain the same. The new platform can measure EMR patterns for neural network (NN) analysis. It also improves the measurement flexibility from simple MCUs to field programmable gate array intellectual properties (FPGA-IPs). In this paper, two DUTs (one MCU and one FPGA-MCU-IP) are tested. Under the same data acquisition and data processing procedures with similar NN architectures, the top1 EMR identification accuracy of MCU is improved. The EMR identification of FPGA-IP is the first to be identified to the authors' knowledge. Thus, the proposed method can be applied to different embedded system architectures for system-level security verification. This study can improve the knowledge of the relationships between EMR pattern recognitions and embedded system security issues.

11.
Anal Chem ; 94(15): 5744-5751, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35385251

RESUMEN

Intracellular reactive oxygen species and reactive sulfur play a vital role in regulating redox homeostasis and maintaining cell functions. Sulfur dioxide (SO2) has emerged as an important gas signal molecule recently, which is not only a potential reducing agent but also a potential inductor of oxidative stress in organisms. Due to high reactivity, peroxynitrite (ONOO-) could act on many biomolecules, such as proteins, lipids, and nucleic acids, and cause irreversible damage, eventually leading to cell apoptosis or necrosis. In order to further illuminate the dichotomous role of SO2 under oxidative stress induced by ONOO-, we designed the first dual-site fluorescent sensor (NIR-GYf) for separate or continuous detection of SO2 and ONOO-. NIR-GYf was successfully used for cell imaging of endogenous SO2 and ONOO-. In addition, western blotting analysis was used to verify the oxidation and antioxidation of SO2 and its dichotomous biological influence. Finally, NIR-GYf was integrated with multiple Boolean logic operations to construct an advanced analysis device, thereby realizing the direct analysis of SO2 and ONOO- levels.


Asunto(s)
Ácido Peroxinitroso , Dióxido de Azufre , Colorantes Fluorescentes , Lógica , Estrés Oxidativo , Dióxido de Azufre/análisis
12.
Inorg Chem ; 61(49): 19658-19662, 2022 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-36448834

RESUMEN

Lanthanide metal-organic framework (Ln-MOF) luminescent sensors monitoring the H2O content in D2O are still rare. We designed and built a hydrophilic mixed Ln-MOF (Eu0.4Tb0.6-MOF) monitoring the H2O content in D2O. By designing a ligand and controlling the synthesis method, we achieved a balance between the structural stability and sensing capacity. When the H2O content ranges from 0 to 100%, the photoluminescence color of Eu0.4Tb0.6-MOF can change from yellow to green, which can be observed by the naked eye. The mechanism is that the photoluminescence intensity of Eu3+ decreases faster than that of Tb3+ when the H2O content increases. The sensing mechanism was studied further by transient fluorescence spectrometry.


Asunto(s)
Elementos de la Serie de los Lantanoides , Estructuras Metalorgánicas , Elementos de la Serie de los Lantanoides/química , Estructuras Metalorgánicas/química , Límite de Detección , Luminiscencia , Espectrometría de Fluorescencia/métodos
13.
Inorg Chem ; 61(32): 12591-12598, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35920803

RESUMEN

Surface states and slow water oxidation kinetics greatly limit the photoelectrochemical (PEC) water oxidation performance of Fe2O3. To solve the above problems, coupling Fe2O3 with a passivation layer and an oxygen evolution cocatalyst, respectively, is the common method. Though this method may improve its PEC performance, this also results in a low charge-transfer efficiency caused by the interface resistance between Fe2O3 and the modification materials (passivation layer and oxygen evolution cocatalyst). Therefore, it is important to identify a multifunctional modifier material to reduce the interfacial resistance due to the presence of multiple different materials. In this work, we introduced a thin cobalt-based metal-organic framework layer (ZIF-67) as a dual-functional material that acted as both a passivation layer and a water oxidation cocatalyst for a photoanode based on Ce-Fe2O3 nanorod arrays. The ZIF-67 layer inhibited charge carrier recombination by passivating the surface states. The PEC performance was improved due to the rich Co2+ photogenerated hole-capture sites, which facilitated charge transfer and separation. As expected, the Ce-Fe2O3/ZIF-67 photoanode exhibited superior water oxidation performance, with a photocurrent of 2.07 mA cm-2 at 1.23 VRHE, which is 1.74 times higher than that of the Ce-Fe2O3 photoanode. The onset potential was negatively shifted by 71 mV. This study provides basic insights and a strategy for reducing interfacial resistance in hybrid materials.

14.
Inorg Chem ; 61(9): 4009-4017, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35188386

RESUMEN

The exploration and development of coordination nanocages can provide an approach to control chemical reactions beyond the bounds of the flask, which has aroused great interest due to their significant applications in the field of molecular recognition, supramolecular catalysis, and molecular self-assembly. Herein, we take the advantage of a semirigid and nonsymmetric bridging ligand (H5L) with rich metal-chelating sites to construct an unusual and discrete 3d-4f metallacage, [Zn2Er4(H2L)4(NO3)Cl2(H2O)]·NO3·xCH3OH·yH2O (Zn2Er4). The 3d-4f Zn2Er4 cage possesses a quadruple-stranded structure, and all of the ligands wrap around an open spherical cavity within the core. The self-assembly of the unique cage not only ensures the structural stability of the Zn2Er4 cage as a nanoreactor in solution but also makes the bimetallic lanthanide cluster units active sites that are exposed in the medium-sized cavity. It is important to note that the Zn2Er4 cage as a homogeneous catalyst has been successfully applied to catalyze three-component aza-Darzens reactions of formaldehyde, anilines, and α-diazo esters without another additive under mild conditions, displaying better catalytic activity, higher specificity, short reaction time, and low catalyst loadings. A possible mechanism for this three-component aza-Darzens reaction catalyzed by the Zn2Er4 cage has been proposed. These experimental results have demonstrated the great potential of the discrete 3d-4f metallacage as a host nanoreactor for the development of supramolecular or molecular catalysis.

15.
Inorg Chem ; 60(4): 2764-2770, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33523673

RESUMEN

The transfer of configuration information from supramolecular helices is a ubiquitous phenomenon in nature. DNA and proteins often change their helical structure in response to particular external stimuli and can activate important related events through sophisticated mechanisms. Attempts to create artificial multiple-stranded helicates that can adjust the configuration under external stimuli have also met with limited success. Using a simple ligand, we now show multiple-stranded lanthanide helicates that transform efficiently. Lanthanide and ligand are successfully self-assembled into different multiple helical supermolecular clusters using different templates. Additionally, these intelligent supermolecular transformers can also be transformed by different external stimuli and realize the selective recognition and fixation of the corresponding ions and molecules.


Asunto(s)
Dióxido de Carbono/química , Elementos de la Serie de los Lantanoides/química , Potasio/química , Cristalografía por Rayos X , Análisis Espectral/métodos
16.
Anticancer Drugs ; 31(10): 1012-1017, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33009034

RESUMEN

Tumor cells can activate platelets, which in turn facilitate tumor cell survival and dissemination. Platelets inhibition or blocking platelet-tumor cell interactions has become a strategy to suppress tumor progression. In this study, we investigated the effect of ticagrelor, a new antiplatelet drug, on tumor cell proliferation and metastasis. Our results show that ticagrelor not only inhibits the proliferation, migration, and invasion of B16F10 and Lewis lung carcinoma cells but also induces platelet apoptosis. In addition, we find that apoptosis of the platelet cells is dose dependent. Further, the result of in-vivo experiments proved that ticagrelor treatment decreased the tumor metastasis. The results of this study demonstrate that ticagrelor may be a potential anti-tumor agent for tumor metastasis.


Asunto(s)
Antineoplásicos/farmacología , Plaquetas/efectos de los fármacos , Carcinoma Pulmonar de Lewis/tratamiento farmacológico , Melanoma Experimental/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/farmacología , Ticagrelor/farmacología , Animales , Apoptosis/efectos de los fármacos , Plaquetas/patología , Carcinoma Pulmonar de Lewis/patología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario , Masculino , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL
17.
Inorg Chem ; 59(19): 13888-13897, 2020 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-32941032

RESUMEN

The Eu2+/3+ mixed-valent complexes have aroused attention because of their potential application in the catalytic field endowed by the variable valence. Herein, we develop an ingenious green strategy to achieve the partial reduction of Eu3+ to Eu2+ ions in the complex of pyrenol-containing cyclen (H4(Pyr)4cyclen, H4[PC]) via a ligand-to-metal charge transfer (LMCT) effect in air at room temperature. To reveal the inherent regulated capacity of the Eu2+/3+ complex in catalysis, we prepared the nanocomposites assembled by the lanthanide complexes encapsulated into ZIF-67 to successively realize the decomposition of H2O2, including europium, gadolinium, and terbium complexes. Among the nanocomposites, Eu2+/3+[PC]H@ZIF-67 exhibits the best catalytic performance due to the achievement of dual regulation of Co3+/Co2+ ratio by the mixed-valent complex. Because of extremely abundant Co2+ active sites, the Eu2+/3+[PC]H@ZIF-67 after catalyzing H2O2 sample was further utilized to degrade organic dye rhodamine B (RhB). The rather outstanding catalytic degradation efficiency was still present in Eu2+/3+[PC]H@ZIF-67. This research presents a facile strategy of Eu3+ reduction based on the ligand design and a new direction for the future development of the composite catalytic materials with mixed-valent complexes.

18.
Inorg Chem ; 59(21): 15681-15689, 2020 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-33064941

RESUMEN

With the rapid development of technology, information security has always been considered a major challenge. In this work, the excellent combination of persistent luminescence, photoluminescence, up-conversion luminescence, and thermo-luminescence in a particular material Zn4B6O13:Tb3+,Yb3+ synthesized via a solid-state reaction is reported, which can be used for the information encryption and anti-counterfeiting. Tb3+ ions were chosen as the emitting centers for multimodal emissions, and Yb3+ codoping can be used as electron traps and sensitizer to adjust trap distribution and efficient up-conversion luminescence in rare-earth-doped luminescent materials. Besides, the as-prepared luminescent materials exhibit high thermal stability and excellent water resistance. On the basis of these properties, the samples were used to print luminescent images through a screen printing process on the film and banknote. The luminescent image in a film is showing different patterns and on a banknote is showing green emissions under different stimulations. These multimodal emissions demonstrate that the as-prepared sample is suitable for advanced information encryption and anti-counterfeiting.

19.
Inorg Chem ; 59(4): 2328-2336, 2020 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-31994877

RESUMEN

One-pot reaction of an asymmetrical acylhydrazone ligand H3L with Ln(ClO4)3 and CuCl2 in MeOH and MeCN solvents resulted in two novel octanuclear complexes, [Cu4Dy4L4Cl6(CH3OH)8(H2O)4]·Cl2(CH3OH)9(H2O)3 (1) and [Cu4Tb4L4Cl6(CH3OH)2(H2O)10]·Cl2(H2O)x (2). Single-crystal X-ray diffraction studies revealed that these two complexes are isostructural and can be viewed as being built from two {Cu2Ln2L2} (Ln = Dy or Tb) butterfly-shaped units. Direct current magnetic susceptibilities and field-dependent magnetization measurements demonstrated the presence of strong ferromagnetic interaction between CuII and LnIII and magnetic anisotropy. Furthermore, alternating current (ac) magnetic measurements illustrated that these two complexes showed temperature- and frequency-dependent signals in the out-of-phase ac susceptibility under zero applied field, which are typical features of the slow relaxation of the magnetization for 1 and 2. The effective energy barrier (Ueff) for 1 was 54 K, which is one of the highest Ueff values yet reported for CuII/LnIII single-molecule magnets.

20.
Anal Bioanal Chem ; 412(2): 481-488, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31728594

RESUMEN

Monitoring and imaging glutathione (GSH) in living systems is an essential tool to determine the key roles of GSH in biological pathways, but most fluorescent sensors can only be used in vitro because of their potential biotoxicity. Here, a peptide-based fluorescent sensor, FP, has been successfully designed and synthesized based on the biocompatibility of the peptide backbone and low toxicity. The design strategy of FP contains a specific spatial structure of the peptide sequence which selectively binds to Cu2+, triggering fluorescence quenching. Interestingly, the fluorescence of FP can be fully restored by GSH, due to the strong binding between Cu2+ and the GSH sulfhydryl groups. Finally, the sensor is highly sensitive and selective for imaging GSH both in vitro and in vivo with low toxicity. Thus, FP with its strong "on-off-on" fluorescence changes is a powerful way to image GSH both in cells and zebrafish larvae to study the GSH pathway.


Asunto(s)
Colorantes Fluorescentes/química , Glutatión/metabolismo , Péptidos/química , Animales , Cromatografía Líquida de Alta Presión , Células HeLa , Humanos , Límite de Detección , Microscopía Fluorescente , Espectrometría de Fluorescencia , Espectrometría de Masa por Ionización de Electrospray , Pez Cebra/embriología
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