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1.
Artigo em Inglês | MEDLINE | ID: mdl-34767166

RESUMO

Tetracycline (TC) is a typical ecotoxic antibiotic, which easily causes bacterial resistance. Therefore, it is necessary to remove TC from the water environment. In recent years, advanced oxidation processes (AOPs) rely on the use of highly reactive oxidizing sulfate radical which is turning into an increasingly popular as a tool of the removal of TC. In this study, cobalt-doped pomelo peel carbon composite (Co-PPCC) was prepared by the impregnation coprecipitation method to activate peroxymonosulfate (PMS) to remove TC. SEM, BET, XRD, FTIR, XPS, TGA, and other analytical techniques indicated that a carbon composite catalyst with excellent performance has been successfully prepared. TC was removed by the synergistic effect of adsorption and catalytic degradation processes. The adsorption capacity was limited (only approximately 20% within 60 min) and tending to saturation, which indicated that the removal of TC in the Co-PPCC/PMS system was mainly due to oxidative degradation. The influence of the Co-PPCC and PMS dosage, initial TC concentration, initial pH values, and coexisting anions on the removal efficiency of TC was investigated. When the Co-PPCC catalyst dosage was 1 g/L, PMS concentration was 2 g/L, and pH value was 11, the removal efficiency of TC with a concentration of 50 mg/L reached 99% within 60 min. Free radical quenching experiment and electron paramagnetic resonance (EPR) analysis indicated that the free radical and non-radical degradation processes exist in the Co-PPCC/PMS/TC system. The main degradation products and the possible transformation pathways of TC were explored by LC-MS. In addition, after four cycles of Co-PPCC tests, the removal efficiency of TC can reach 64%. This study provides a new method to reuse abandoned pomelo peels and synthesize an economical and environmentally friendly catalyst for activating peroxymonosulfate to remove TC antibiotics in water.

2.
ChemSusChem ; 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34783202

RESUMO

Electrochemical nitrogen reduction reaction (NRR) is intensively investigated by researchers for its potential to be the next generation technology to produce ammonia. Many attempts have been made to explore the possibility of electrochemical ammonia production catalyzed by noble metals. However, the produced ammonia in most reported cases is in ppm level or even lower, which is susceptible to potential contaminants in experiments, leading to fluctuated even contradictory results. Herein, rigorous procedure was adopted to systematically evaluated the performance of commercial noble metals nano-catalysts toward NRR. And no discernible amount of ammonia was detected in either acidic or alkaline solutions. Further, we detected and characterized nitrogen-containing contaminants in catalysts which might cause false positive results. An effective way to remove pre-exist pollutants by consecutive cyclic voltammetry scan is proposed, helping to obtain reliable and reproducible results.

4.
J Mater Chem B ; 9(37): 7734-7740, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586149

RESUMO

Superparamagnetic iron oxide nanoparticles with high magnetization strength and good biological safety have been widely used as magnetic resonance imaging (MRI) contrast agents for tumors. However, the accuracy of tumor diagnosis is still low due to the lack of tumor targeting and the interference signals from normal tissues. Endogenous substances in tumor (such as high levels of GSH and pH) stimuli-responsive contrast agents could offer higher sensitivity for tumor diagnosis. Herein, based on the characteristic of overexpression of GSH in tumors, we propose an ultra-small Fe3O4 assembly as an endogenous GSH responsive MRI contrast agent. The ultra-small superparamagnetic Fe3O4 are bonded to the crosslinker cystamine to synthesize Fe3O4 nanoclusters, which exhibit a T2 imaging effect. When the contrast agent reaches the tumor tissue, the disulfide bond in cystamine is induced by GSH to break, the Fe3O4 nanoclusters are disassembled into ultra-small Fe3O4 nanoparticles, and the relaxation signal changes from T2 to T1, which is helpful for accurate diagnosis of tumors. In vivo experiments have shown that Fe3O4 nanoclusters can rapidly respond to overexpressed GSH in tumor sites for T2/T1 switchable imaging. This work not only designed an endogenous GSH responsive platform through simple synthesis methods, but also improved the accuracy of tumor diagnosis through the transformation of T2/T1 MRI signals.

5.
J Mater Chem B ; 9(41): 8631-8638, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34585715

RESUMO

Gd(III) chelates are important T1-weighted contrast agents used in clinical magnetic resonance imaging (MRI), but their low longitudinal relaxivity (r1) results in limited imaging efficiency. In this study, we utilize a geometric confinement strategy to restrict a Gd chelate (Gd-DTPA) within the channels of a porous metal-organic framework material (MOF-808) for increasing its r1 relaxivity. Moreover, the Gd-DTPA-grafted MOF-808 nanoparticles were further surface modified with polyaniline (PANI) to construct an MRI-guided photothermal therapy platform. The resulting Gd-DTPA-MOF-808@PANI shows a high r1 relaxivity of 30.1 mM-1 s-1 (0.5 T), which is 5.4 times higher than that of the commercial contrast agent Magnevist. In vivo experiments revealed that Gd-DTPA-MOF-808@PANI has good T1-weighted contrast performance and can effectively guide photothermal ablation of tumors upon 808 nm laser irradiation. This work may shed some light on the design and preparation of high relaxation rate Gd-based contrast agents for theranostic application via utilization of versatile MOF materials.

6.
Chem Commun (Camb) ; 57(69): 8612-8615, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34369527

RESUMO

Here, we constructed Pb-free Cu-DABDT-MOFs-based (DABDT = 2,5-diamino-1,4-benzenedithiol) X-ray detectors. Combined with the advantage of high activation energy, the Cu-DABDT-MOFs-based detector can effectively generate and capture electrons under X-ray exposure and presents a high mobility-lifetime (µτ) product of 6.49 × 10-4 cm2 V-1 and promising detection sensitivity of 78.7 µC Gyair-1 cm-2. As groundbreaking work, these discoveries have provided information for exploring MOF materials toward green and high-performance high-energy radiation detectors by exploiting the designable structure and tunable properties of the MOF family.

7.
Geophys Res Lett ; 48(6): e2020GL091342, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-34219836

RESUMO

Humboldt Gletscher is a 100-km wide, slow-moving glacier in north Greenland which holds a 19-cm global sea level equivalent. Humboldt has been the fourth largest contributor to sea level rise since 1972 but the cause of its mass loss has not been elucidated. Multi-beam echo sounding data collected in 2019 indicate a seabed 200 m deeper than previously known. Conductivity temperature depth data reveal the presence of warm water of Atlantic origin at 0°C at the glacier front and a warming of the ocean waters by 0.9 ± 0.1°C since 1962. Using an ocean model, we reconstruct grounded ice undercutting by the ocean, combine it with calculated retreat caused by ice thinning to floatation, and are able to fully explain the observed retreat. Two thirds of the retreat are caused by undercutting of grounded ice, which is a physical process not included in most ice sheet models.

8.
ACS Appl Mater Interfaces ; 13(24): 28703-28709, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34101425

RESUMO

Two-dimensional (2D) metal-molecule hybrid frameworks have attracted great attention due to their π-d interactions for the charge-spin-lattice coupling, promising for next-generation molecular electronics. However, a high electrical conductivity is indispensable to realize such potential. Herein, we design and assemble a conductive 2D conjugated coordination thin film through an interfacial reaction between the aqueous and organic phases. Its electronic conducting properties are derived from the π-d coupling interactions to achieve an electrical conductivity of 1.05 S/cm, while the stimulus-dependent π-d interactions induce multifunctional sensory capabilities. The Co-DABDT (DABDT = 2,5-diamino-1,4-benzenedithiol dihydrochloride) thin films demonstrate an excellent performance for sensing light, strain, temperature, and humidity, as well as robust mechanical stability. The 2D frameworks with multisensing properties for real-time static and dynamic monitoring are promising for smart wearable electronic systems.

9.
Radiat Res ; 196(3): 250-260, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34107043

RESUMO

Severe radiation-induced skin injury is a complication of tumor radiotherapy and nuclear accidents. Cell therapy is a potential treatment for radiation-induced skin injury. The stromal vascular fraction (SVF) is a newer material in stem cell therapy that is made up of stem cells harvested from adipose tissue, which has been shown to promote the healing of refractory wounds of different causes. In this study, SVF was isolated from patients with radiation-induced skin injury. Adipose-derived stem cells (ADSCs) accounted for approximately 10% of the SVF by flow cytometry. Compared with the control group of rats, administration with SVF attenuated the skin injury induced by electron beam radiation. The effect of SVF on the human skin fibroblast microenvironment was determined by proteomic profiling of secreted proteins in SVF-co-cultured human skin fibroblast WS1 cells. Results revealed 293 upregulated and 1,481 downregulated proteins in the supernatant of SVF-co-cultured WS1 cells. WS1 co-culture with SVF induced secretion of multiple proteins including collagen and MMP-1. In the clinic, five patients with radiation-induced skin injury were recruited to receive SVF transfer-based therapy, either alone or combined with flap transplantation. Autogenous SVF was isolated and introduced into a multi-needle precision electronic injection device, which automatically and aseptically distributed the SVF to the exact layer of the wound in an accurate amount. After SVF transfer, wound healing clearly improved and pain was significantly relieved. The patients' skin showed satisfactory texture and shape with no further wound recurrence. Our findings suggest that transplantation of SVF could be an effective countermeasure against severe radiation-induced skin injury.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Radiodermatite/terapia , Adulto , Aloenxertos , Animais , Células Cultivadas , Técnicas de Cocultura , Meios de Cultivo Condicionados , Elétrons/efeitos adversos , Feminino , Fibroblastos/metabolismo , Ontologia Genética , Redes Reguladoras de Genes , Traumatismos da Mão/terapia , Xenoenxertos , Humanos , Radioisótopos de Irídio/efeitos adversos , Masculino , Transplante de Células-Tronco Mesenquimais/instrumentação , Transplante de Células-Tronco Mesenquimais/métodos , Pessoa de Meia-Idade , Proteoma , Lesões Experimentais por Radiação/terapia , Radiodermatite/etiologia , Radiodermatite/patologia , Radiodermatite/cirurgia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Pele/efeitos da radiação , Organismos Livres de Patógenos Específicos , Retalhos Cirúrgicos
10.
Nano Lett ; 21(9): 4099-4105, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33886320

RESUMO

Magnetoelectrics are witnessing an ever-growing success toward the voltage-controlled magnetism derived from inorganic materials. However, these inorganic materials have predominantly focused on the ferroelectromagnetism at solid-to-solid interfaces and suffered several drawbacks, including the interface-sensitive coupling mediators, high-power electric field, and limited chemical tunability. Here, we report a promising design strategy to shift the paradigm of next-generation molecular magnetoelectrics, which relies on the integration between molecular magnetism and electric conductivity though an in situ cross-linking strategy. Following this approach, we demonstrate a versatile and efficient synthesis of flexible molecular-based magnetoelectronics by cross-linking of magnetic coordination networks that incorporate conducting chain building blocks. The as-grown compounds feature an improved critical temperature up to 337 K and a room-temperature magnetism control of low-power electric field. It is envisaged that the cross-linking of molecular interfaces is a feasible method to couple and modulate magnetism and electron conducting systems.

11.
Dalton Trans ; 50(15): 5124-5127, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33881107

RESUMO

We report here the dealloying treatment on a RuNiOx catalyst for enhanced acidic oxygen evolution reaction (OER) performance. Specifically, the dealloyed RuNiOx is capable of delivering a current density of 50 mA cm-2 at a low overpotential of 280 mV and demonstrates superior stability after 10 000 potential cycles.

12.
Sci Adv ; 7(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33523831

RESUMO

The retreat and acceleration of Greenland glaciers since the mid-1990s have been attributed to the enhanced intrusion of warm Atlantic Waters (AW) into fjords, but this assertion has not been quantitatively tested on a Greenland-wide basis or included in models. Here, we investigate how AW influenced retreat at 226 marine-terminating glaciers using ocean modeling, remote sensing, and in situ observations. We identify 74 glaciers in deep fjords with AW controlling 49% of the mass loss that retreated when warming increased undercutting by 48%. Conversely, 27 glaciers calving on shallow ridges and 24 in cold, shallow waters retreated little, contributing 15% of the loss, while 10 glaciers retreated substantially following the collapse of several ice shelves. The retreat mechanisms remain undiagnosed at 87 glaciers without ocean and bathymetry data, which controlled 19% of the loss. Ice sheet projections that exclude ocean-induced undercutting may underestimate mass loss by at least a factor of 2.

13.
Molecules ; 26(3)2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33535547

RESUMO

It is counterintuitive that chemical reactions can be accelerated by freezing, but this amazing phenomenon was discovered as early as the 1960s. In frozen systems, the increase in reaction rate is caused by various mechanisms and the freeze concentration effect is the main reason for the observed acceleration. Some accelerated reactions have great application value in the chemistry synthesis and environmental fields; at the same time, certain reactions accelerated at low temperature during the storage of food, medicine, and biological products should cause concern. The study of reactions accelerated by freezing will overturn common sense and provide a new strategy for researchers in the chemistry field. In this review, we mainly introduce various mechanisms for accelerating reactions induced by freezing and summarize a variety of accelerated cryochemical reactions and their applications.


Assuntos
Compostos Orgânicos/química , Fragmentos de Peptídeos/química , Proteínas/química , Animais , Congelamento , Humanos , Concentração de Íons de Hidrogênio , Cinética , Polimerização
14.
J Mater Chem B ; 9(7): 1787-1791, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33595044

RESUMO

Iron-based coordination complexes are showing increasing potential to be alternatives for T1-weighted magnetic resonance imaging (MRI) and contribute to the safety of gadolinium-based compounds. In this work, three water-soluble iron-based complexes constructed using catechol ligands exhibiting T1-weighted MRI contrast behavior are described. The longitudinal relaxivity (r1) increase from 0.88 to 1.43 mM-1 s-1 mainly depends on the sizes and the number of water molecules in the second and outer spheres around the discrete complexes.


Assuntos
Materiais Biocompatíveis/química , Meios de Contraste/química , Compostos Férricos/química , Imageamento por Ressonância Magnética , Animais , Linhagem Celular , Humanos , Camundongos , Estrutura Molecular , Tamanho da Partícula , Solubilidade , Propriedades de Superfície , Água/química
16.
J Cell Biochem ; 122(3-4): 442-455, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33399227

RESUMO

As a posttranscriptional regulatory factor, microRNA (miRNA) plays an important role in the formation of myotubes. However, little is known about the mechanism of miRNA regulating myotube morphogenesis. Here, we aimed to characterize the function of miR-455-5p in myotube morphogenesis by inducing differentiation in C2C12 myoblasts containing murine Mylip fragments with the miR-455-5p target sequence. We found that miR-455-5p overexpression promoted the differentiation and hypertrophy of myotubes, while miR-455-5p inhibition led to the failure of myotube differentiation and formation of short myotubes. Furthermore, we demonstrated that miR-455-5p directly targeted the Mylip 3'-untranslated region, which plays a key role in monitoring myotube morphogenesis. Interestingly, the expression and function of Mylip were opposite to those of miR-455-5p during myogenesis. Our data uncovered novel miR-455-5p targets and established a functional link between Mylip and myotube morphogenesis. Understanding the involvement of Mylip in myotube morphogenesis provides insight into the function of the gene regulatory network.


Assuntos
Diferenciação Celular/fisiologia , MicroRNAs/metabolismo , Mioblastos/citologia , Mioblastos/metabolismo , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Proliferação de Células/fisiologia , Humanos , MicroRNAs/genética , Desenvolvimento Muscular/genética , Desenvolvimento Muscular/fisiologia
17.
Prostate ; 81(2): 118-126, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33152137

RESUMO

OBJECTIVE: Prostate cancer (PCa) incidence has stabilized but not in patients at a young age. We assessed patient characteristics and disease progression in early-onset PCa. METHODS: A retrospective cohort of 28,039 newly diagnosed PCa patients aged ≥35 years was constructed using the Taiwan Cancer Registry in 2008-2016. Patients were categorized by age at diagnosis (≤54, 55-59, 60-69, 70-74, and ≥75 years). The clinical stage at diagnosis, Gleason score, prostate-specific antigen level at diagnosis, Charlson's comorbidity index, and primary and secondary treatments for PCa were included in the analysis. All-cause mortality and prostate cancer-specific mortality (PCSM) were reported. Hazard ratios (HRs) and 95% confidence intervals (CIs) estimating the risks of death and of receiving secondary cancer treatment were generated by Cox hazard models. RESULTS: In patients aged ≤54, 55-59, and 60-69 years, about 60% of them in each group were classified into the high-risk, very high-risk, or metastatic group. However, young patients ≤54 years had a higher risk of PCSM than patients aged 60-69 years (HR = 1.22; 95% CI = 1.10-1.49). This trend of an increased risk in PCSM remained for high-risk, very high-risk, or metastatic patients (HR = 1.24; 95% CI = 1.01-1.51), but not in low- or intermediate-risk patients. Besides, young patients diagnosed with high-risk diseases had the highest risk of receiving secondary cancer treatment within 180 days after completing primary treatment among all age groups (HR = 1.32; 95% CI = 1.07-1.63). CONCLUSIONS: PCa arising in young patients ≤54 years of age, especially those with a high risk or metastatic form, might be more aggressive than that in other age groups.


Assuntos
Fatores Etários , Progressão da Doença , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Adulto , Idoso , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Antígeno Prostático Específico/análise , Neoplasias da Próstata/terapia , Estudos Retrospectivos , Fatores de Risco , Taiwan
18.
Nanomedicine ; 32: 102335, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33220508

RESUMO

Targeted T1-T2 MRI contrast agents, which can eliminate the difficulty of image matching across multiple imaging instruments and permit specific localization of lesions, are promising candidates for more accurate diagnosis of tumors. In this study, ultrasmall Fe@Fe3O4 nanoparticles were designed and synthesized as T1-T2 dual-mode MRI contrast agents for accurate tumor imaging. First, to investigate the influence of nanoparticle size, Fe@Fe3O4 nanoparticles with diameters of 4, 8, and 12 nm were prepared, among which the 8 nm 3-(3,4-dihydroxyphenyl)propionic acid (DHCA)-modified nanoparticles exhibited the optimal T1-T2 dual-mode MRI performance. Next, to develop a tumor-targeted contrast agent, the DHCA-Fe@Fe3O4 nanoparticles were conjugated with the F56 peptide, which targets the vascular endothelial growth factor receptor, and the resulting F56-DHCA-Fe@Fe3O4 nanoparticles were found to exhibit good T1-T2 dual-mode imaging and tumor-targeting performance both in vitro and in vivo, indicating the nanoparticles represent a new research tool for accurate tumor diagnosis.

19.
J Med Chem ; 64(1): 871-889, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33332136

RESUMO

The NLRP3 inflammasome is a critical component of innate immunity, which defends internal and external threats. However, inappropriate activation of the NLRP3 inflammasome induces various human diseases. In this study, we discovered and synthesized a series of tetrahydroquinoline inhibitors of NLRP3 inflammasome. Among these analogues, compound 6 exhibited optimal NLRP3 inhibitory activity. In vitro studies indicated that compound 6 directly bound to the NACHT domain of NLRP3 but not to protein pyrin domain (PYD) or LRR domain, inhibited NLRP3 ATPase activity, and blocked ASC oligomerization, thereby inhibiting NLRP3 inflammasome assembly and activation. Compound 6 specifically inhibited the NLRP3 inflammasome activation, but had no effect on the activation of NLRC4 or AIM2 inflammasomes. Furthermore, in the dextran sulfate sodium (DSS)-induced colitis mouse model, compound 6 exhibited significant anti-inflammatory activity through inhibiting NLRP3 inflammasome in vivo. Therefore, our study provides a potent NLRP3 inflammasome inhibitor, which deserves further structural optimization as a novel therapeutic candidate for NLRP3-driven diseases.


Assuntos
Anti-Inflamatórios/uso terapêutico , Colite/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Quinolinas/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colite/induzido quimicamente , Colite/patologia , Sulfato de Dextrana/toxicidade , Desenho de Fármacos , Feminino , Humanos , Concentração Inibidora 50 , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Quinolinas/metabolismo , Quinolinas/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
20.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33372140

RESUMO

Zachariae Isstrøm (ZI) and Nioghalvfjerdsfjorden (79N) are marine-terminating glaciers in northeast Greenland that hold an ice volume equivalent to a 1.1-m global sea level rise. ZI lost its floating ice shelf, sped up, retreated at 650 m/y, and experienced a 5-gigaton/y mass loss. Glacier 79N has been more stable despite its exposure to the same climate forcing. We analyze the impact of ocean thermal forcing on the glaciers. A three-dimensional inversion of airborne gravity data reveals an 800-m-deep, broad channel that allows subsurface, warm, Atlantic Intermediate Water (AIW) (+1.[Formula: see text]C) to reach the front of ZI via two sills at 350-m depth. Subsurface ocean temperature in that channel has warmed by 1.3[Formula: see text]C since 1979. Using an ocean model, we calculate a rate of ice removal at the grounding line by the ocean that increased from 108 m/y to 185 m/y in 1979-2019. Observed ice thinning caused a retreat of its flotation line to increase from 105 m/y to 217 m/y, for a combined grounding line retreat of 13 km in 41 y that matches independent observations within 14%. In contrast, the limited access of AIW to 79N via a narrower passage yields lower grounded ice removal (53 m/y to 99 m/y) and thinning-induced retreat (27 m/y to 50 m/y) for a combined retreat of 4.4 km, also within 12% of observations. Ocean-induced removal of ice at the grounding line, modulated by bathymetric barriers, is therefore a main driver of ice sheet retreat, but it is not incorporated in most ice sheet models.

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