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1.
Emerg Microbes Infect ; 8(1): 1445-1455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31595827

RESUMO

Coxsackievirus A4 (CVA4) infection can cause hand, foot and mouth disease (HFMD), an epidemic illness affecting neonatal and paediatric cohorts, which can develop to severe neurological disease with high mortality. In this study, we established the first ICR mouse model of CVA4 infection for the evaluation of inactivated vaccines and antiviral drug screening. The CVA4 YT226R strain was selected to infect the neonatal mice and three infectious factors were optimized to establish the infection model. The 3-day-old neonatal mice exhibited clinical symptoms such as hind limb paralysis and death. The severe inflammatory reactions were closely related to the abnormal expression of the acute phase response proinflammatory cytokine IL-6 and an imbalance in the IFN-γ/IL-4 ratio. Importantly, the inactivated CVA4 whole-virus vaccine induced humoral immune responses in adult females and the maternal antibodies afforded mice complete protection against lethal dose challenges of homologous or heterologous CVA4 strains. Both IFN-α2a and antiserum inhibited the replication of CVA4 and increased the survival rates of neonatal mice during the early stages of infection. This neonatal murine model of CVA4 infection will be useful for the development of prophylactic and therapeutic vaccines and for screening of antiviral drugs targeting CVA4 to decrease morbidity and mortality.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31614055

RESUMO

Preparation of large single crystals of linear polymers for X-ray analysis is very challenging. Herein, we employ a coordination-driven self-assembly strategy to secure the appropriate head-to-tail alignment of anthracene moieties, and for the first time obtained large-sized Pt-based linear polymer crystals through a [4+4] cycloaddition of anthracene in a single-crystal to single-crystal fashion. Using X-ray diffraction to determine the polymer crystal structure, we found that both the polymerisation and depolymerisation steps proceed via a stable intermediate. Taking advantage of the temperature-dependent slow depolymerization, the Pt-based linear polymer showed potential as a sustained release anticancer drug platform. Utilizing the reversible contraction effect of unit-cell volume upon irradiation or heating, the stimuli-responsive crystals were hybridized with polyvinylidene fluoride to obtain a "smart material" with outstanding photoactuator performance.

3.
Top Curr Chem (Cham) ; 377(6): 34, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31664532

RESUMO

Given the unique properties of metal-organic frameworks (MOFs) including adjustable porosity, high surface area, and easy modification, they have attracted great attention as excellent solid supports for the incorporation of biomolecules. The formed biomolecules-MOFs composites show promising prospects in various fields such as biocatalysis, drug delivery, and biosensing. This review focuses on the state-of-the-art of biomolecules-incorporation using MOFs. Moreover, the relationship between properties of MOFs and biomolecules-incorporation is also discussed and highlighted. We hope this work will inspire the innovation in this emerging field for highly efficient synthesis of biomolecules-MOFs composites with various properties and advanced applications.


Assuntos
Estruturas Metalorgânicas/química , Adsorção , DNA/química , Porosidade , Proteínas/química , Propriedades de Superfície
4.
Appl Spectrosc ; : 3702819871627, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31397585

RESUMO

As a technique capable of rapid, nondestructive, and multi-elemental analysis, portable X-ray fluorescence (pXRF) has applications to mineral exploration, environmental evaluation, and archaeological analysis. However, few applications have been conducted in the smelting industry especially when analyzing the metal concentration in ore concentrate samples. This research analyzed the effectiveness of using pXRF in determining the metal concentration in Fe concentrate. For this proof of concept study, Fe ore samples dominated by Fe and Si were collected from the Northeastern University Mineral Processing Laboratory (Shenyang, China) and directly analyzed using pXRF, laboratory-based XRF, and titration methods. The compactness (density) of the ore concentrate was found to have very little effect on pXRF readings. The pXRF readings for Fe and Si were comparative to laboratory-based XRF results. Based on the strong correlations between the pXRF and XRF results (Fe: R2 > 0.99, Si: R2 > 0.96), linear calibrations were adopted to improve the accuracy of pXRF readings. Linear regression equations derived from the relations between XRF results and pXRF results of 21 Fe ore concentrate samples were used to calibrate the pXRF, and then validation was performed on five additional samples. Results from this preliminary study suggest that ordinary least squares (OLS) regression improves the accuracy dramatically, especially for Fe with relative errors (REs) decreasing to 0.03%-3.27% from 4.26%-8.32%. Consequently, pXRF shows strong promise for rapid, quantitative analysis of Fe concentration in Fe ore concentrate. Based on the results obtained in this study, a larger, more comprehensive study is warranted to confirm the results obtained.

5.
J Am Chem Soc ; 141(36): 14443-14450, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31431009

RESUMO

The corrole unit from the porphyrinoid family represents one of the most important ligands in the field of coordination chemistry, which creates a unique environment allowing for the observation of unusual electronic states of bound metal cations and has shown great promise in various applications. Nevertheless, studies that directly and systematically introduce these motifs in porous crystalline materials for targeting further functionalizations are still lacking. Herein, we report for the first time the construction of two robust corrole-based metal-organic frameworks (MOFs), M6(µ3-O)4(µ3-OH)4(OH)3(H2O)3(H3TCPC)3 (M = Zr for Corrole-MOF-1 and M = Hf for Corrole-MOF-2, H3TCPC = 5,10,15-tris(p-carboxylphenyl)corrole), which are assembled by a custom-designed C2ν-symmetric corrolic tricarboxylate ligand and the unprecedented D3d-symmetric 9-connected Zr6/Hf6 clusters. The resultant frameworks feature a rare (3,9)-connected gfy net and exhibit high chemical stability in aqueous solutions within a wide range of pH values. Furthermore, we successfully prepared the cationic Corrole-MOF-1(Fe) from the iron corrole ligand, which can serve as an efficient heterogeneous catalyst for [4 + 2] hetero-Diels-Alder reactions between unactivated aldehydes and a simple diene, outperforming both the homogeneous counterpart and the porphyrinic MOF counterpart.

6.
Angew Chem Int Ed Engl ; 58(45): 16071-16076, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31469218

RESUMO

In the evolution of metal-organic frameworks (MOFs) for carbon capture, a lasting challenge is to strike a balance between high uptake capacity/selectivity and low energy cost for regeneration. Meanwhile, these man-made materials have to survive from practical demands such as stability under harsh conditions and feasibility of scale-up synthesis. Reported here is a new MOF, Zn(imPim) (aka. MAF-stu-1), with an imidazole derivative ligand, featuring binding pockets that can accommodate CO2 molecules in a fit-like-a-glove manner. Such a high degree of shape complementarity allows direct observation of the loaded CO2 in the pockets, and warrants its optimal carbon capture performances exceeding the best-performing MOFs nowadays. Coupled with the record thermal (up to 680 °C) and chemical stability, as well as rapid large-scale production, both encoded in the material design, Zn(imPim) represents a most competitive candidate to tackle the immediate problems of carbon dioxide capture.

7.
J Am Chem Soc ; 141(30): 12064-12070, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31287954

RESUMO

Fabrication of hybrid membranes composed of porous materials embedded in polymer matrices is a subject of topical interest. Herein, we introduce a new class of hybrid membranes: hyper-cross-linked metal-organic polyhedra (HCMOPs). These membranes are based upon soluble MOPs that can serve as high-connectivity nodes in hyper-cross-linked polymer networks. HCMOPs spontaneously form macro-scale, defect-free, freestanding membranes, and, thanks to the covalent cross-linking of MOPs, the resulting membranes possess multiple functionalities: strong water permeability; self-healing ability; antimicrobial activity; and better separation and mechanical performance than pristine polyimine membranes. This study introduces a new concept for the design and fabrication of multifunctional membranes and also broadens the applications of MOPs.

8.
Inorg Chem ; 58(15): 9916-9921, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31318535

RESUMO

Carbonic anhydrase (CA) mimicking is an effective and environmentally friendly strategy for carbon dioxide sequestration. Herein, we developed a nonanuclear CA-mimetic zinc coordination complex (1) which possesses a coordination environment similar to that of CA's catalytically active zinc sites. Complex 1 exhibited excellent reusability, solvent and thermal stability, and gram-scale synthesis, which are essential for practical applications. It was found that complex 1 exhibited outstanding catalytic performance that is much better in comparison to that of the popular CA-mimetic compound Zn-cyclen and comparable to that of the reported metal-organic frameworks (e.g., CFA-1). Moreover, we found that its catalytic activity can be significantly improved via OAc-/OH- exchange and particle size reduction treatment. This study provides important guidance for the design of highly efficient CA-mimetic materials.

9.
ACS Appl Mater Interfaces ; 11(26): 23192-23197, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184107

RESUMO

Inspired by the structure of carbonic anhydrase, we developed a robust ultramicroporous lanthanide metal-organic framework (MOF) platform (NKMOF-3-Ln), which possesses a porous pocket to selectively bind with CO2 at ambient conditions. Notably, CO2 molecules can be precisely observed in the single-crystal structure of NKMOF-3-Ln. Highly ordered CO2 molecules can strongly interact with the framework via electrostatic interaction of nitrates. We found that the CO2 adsorption capacity and binding energy were gradually enhanced as lanthanide contraction. The strong CO2 binding affinity endows NKMOF-3-Ln with excellent CO2 separation performance, which is verified by experimental breakthrough results. Moreover, because of the specific binding affinity of CO2, NKMOF-3-Eu showed a fluorescence response to CO2.

10.
Inorg Chem ; 58(13): 8787-8792, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31247848

RESUMO

Highly efficient and selective removal of pharmaceuticals and personal care products (PPCPs) from wastewater is a great challenge and is significant. In this study, we chose UiO-66-R, which contains eight isostructural metal-organic frameworks (MOFs) with variable functional groups (-R), as a platform for systemically investigating the influence of functionalization on its adsorption behavior with respect to three classic PPCPs. We conducted kinetic, modeling, and structure-function relationship studies on PPCP removal using MOFs. The adsorption kinetics, including the adsorption rate, affinity, and separation factor ( RL), were comprehensively analyzed and simulated. The design and function of MOFs can greatly promote their adsorption capacity and the efficiency of PPCPs. The structure-function relationship study revealed that hydrogen bonding, electrostatic, and π-π interactions between MOFs and PPCP molecules played important roles in the adsorption process and significantly influenced the adsorption efficiency. This study paves a new way for the application of MOFs with respect to the removal of PPCP pollution and provides guidance for the design of new porous materials for environmental treatment and separation applications.


Assuntos
Estruturas Metalorgânicas/química , Poluentes Químicos da Água/química , Ácido 2,4-Diclorofenoxiacético/química , Adsorção , Anti-Inflamatórios não Esteroides/química , Ácido Clofíbrico/química , Diclofenaco/química , Herbicidas/química , Ligações de Hidrogênio , Cinética , Estruturas Metalorgânicas/síntese química , Mutagênicos/química , Porosidade , Eletricidade Estática
11.
Angew Chem Int Ed Engl ; 58(30): 10209-10214, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31059186

RESUMO

Simultaneous removal of trace amounts of propyne and propadiene from propylene is an important but challenging industrial process. We report herein a class of microporous metal-organic frameworks (NKMOF-1-M) with exceptional water stability and remarkably high uptakes for both propyne and propadiene at low pressures. NKMOF-1-M separated a ternary propyne/propadiene/propylene (0.5 : 0.5 : 99.0) mixture with the highest reported selectivity for the production of polymer-grade propylene (99.996 %) at ambient temperature, as attributed to its strong binding affinity for propyne and propadiene over propylene. Moreover, we were able to visualize propyne and propadiene molecules in the single-crystal structure of NKMOF-1-M through a convenient approach under ambient conditions, which helped to precisely understand the binding sites and affinity for propyne and propadiene. These results provide important guidance on using ultramicroporous MOFs as physisorbent materials.

12.
J Nat Prod ; 82(5): 1089-1097, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31063370

RESUMO

Coxsackievirus A16 (CVA16) is one of the most prevalent enteroviral pathogens associated with hand, foot, and mouth disease. In the present study, we have investigated (1) whether the bioactive compound acetylshikonin (AS) inhibits CVA16 infection in vitro and in vivo and (2) the potential antiviral mechanism(s). The results suggest that AS is nontoxic at concentrations of up to 5 µmol/L and could directly inactivate virus particles at relatively low concentrations (0.08 µmol/L), thereby rendering CVA16 incapable of cellular entry. Correspondingly, the expression of viral RNA in vitro was also reduced 100-fold ( P < 0.05) when compared to infected, untreated controls. Results from a CVA16-infected neonatal mouse model indicate that, in comparison to the virus-infected, untreated group, body weights of the mice in the virus-infected, compound-treated group increased more steadily with less severe clinical symptoms. In addition, viral loads in internal organs significantly decreased in treated animals, concomitantly with both reduced pathology and diminished expression of the proinflammatory cytokines IFN-γ and IL-6. In conclusion, AS exerted an inhibitory effect on CVA16 infection in vitro and in vivo. Our study provides a basis for further investigations of AS-type compounds to develop therapeutics to mitigate CVA-associated disease in children.

13.
J Am Chem Soc ; 141(23): 9408-9414, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117669

RESUMO

Soft porous crystals (SPCs) that exhibit stimuli-responsive dynamic sorption behavior are attracting interest for gas storage/separation applications. However, the design and synthesis of SPCs is challenging. Herein, we report a new type of SPC based on a [2 + 3] imide-based organic cage (NKPOC-1) and find that it exhibits guest-induced breathing behavior. Various gases were found to induce activated NKPOC-1 crystals to reversibly switch from a "closed" nonporous phase (α) to two porous "open" phases (ß and γ). The net effect is gate-opening behavior induced by CO2 and C3 hydrocarbons. Interestingly, NKPOC-1-α selectively adsorbs propyne over propylene and propane under ambient conditions. Thus, NKPOC-1-α has the potential to separate binary and ternary C3 hydrocarbon mixtures, and the performance was subsequently verified by fixed bed column breakthrough experiments. In addition, molecular dynamics calculations and in situ X-ray diffraction experiments indicate that the gate-opening effect is accompanied by reversible structural transformations. The adsorption energies from molecular dynamics simulations aid are consistent with the experimentally observed selective adsorption phenomena. The understanding gained from this study of NKPOC-1 supports the further development of SPCs for applications in gas separation/storage because SPCs do not inherently suffer from the recyclability problems often encountered with rigid materials.

14.
Rev Med Virol ; 29(4): e2046, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31016795

RESUMO

Long noncoding RNAs (lncRNAs) represent a key class of cellular regulators, involved in the modulation and control of multiple biological processes. Distinct classes of lncRNAs are now known to be induced by host cytokines following viral infections. Current evidence demonstrates that lncRNAs play essential roles at the host-pathogen interface regulating viral infections by either innate immune responses at various levels including activation of pathogen recognition receptors or by epigenetic, transcriptional, and posttranscriptional effects. We review the newly described mechanisms underlying the interactions between lncRNAs, cytokines, and metabolites differentially expressed following viral infections; we highlight the regulatory networks of host antiviral responses and emphasize the need for interdisciplinary research between lncRNA biology and immunology to deepen understanding of viral pathogenesis.

15.
Parasitol Int ; 71: 80-86, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30974206

RESUMO

To assess the prevalence and molecular characteristics of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in grazing adult sheep from Xinjiang Uygur Autonomous Region, China, 318 fecal samples were collected and screened for the presence of these parasites by polymerase chain reaction. The overall infection rate for the three pathogens was 13.5% (43/318), with observed individual infection rates of 0.9% (3/318), 7.5% (24/318), and 6.3% (20/318) for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. Three Cryptosporidium species were identified amongst the samples, including C. xiaoi (n = 1), C. ubiquitum (n = 1), and C. parvum (n = 1), with gp60-based subtyping analysis identifying C. parvum as subtype IIdA15G1 and C. ubiquitum as subtype XIIa. Eight E. bieneusi genotypes were identified based on internal transcribed spacer region sequencing, including six known (BEB6, CHG1, CHG3, CHS3, CHS8, and COS-I) and two novel (designated XJS1 and XJS2) genotypes. All G. duodenalis-positive samples were identified as assemblage E based on small subunit rRNA (n = 24) and gdh (n = 10) gene sequence analysis. These data support the occurrence of host adaptation by Cryptosporidium spp., G. duodenalis, and E. bieneusi in sheep, and the zoonotic risk may posed by these parasites in Xinjiang, China.


Assuntos
Cryptosporidium/genética , Enterocytozoon/genética , Giardia lamblia/genética , Ovinos/parasitologia , Animais , China/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/classificação , DNA Intergênico/genética , Enterocytozoon/classificação , Fezes/parasitologia , Genótipo , Giardia lamblia/classificação , Giardíase/epidemiologia , Giardíase/veterinária , Microsporidiose/epidemiologia , Microsporidiose/veterinária , Prevalência , RNA Ribossômico/genética , Análise de Sequência de DNA , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia
16.
Chem Commun (Camb) ; 55(38): 5423-5426, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-30957115

RESUMO

A squaramide-decorated COF was synthesized and used as a highly efficient heterogeneous catalyst for hydrogen-bonding organocatalysis as exemplified in the context of catalyzing Michael addition reactions under mild conditions. Our work lays a foundation for the development of functional COFs as a new platform for biomimetic organocatalysis.

17.
Chemistry ; 25(22): 5611-5622, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30632218

RESUMO

Photomechanical molecular crystals are receiving much attention due to their efficient conversion of light into mechanical work and advantages including faster response time; higher Young's modulus; and ordered structure, as measured by single-crystal X-ray diffraction. Recently, various photomechanical crystals with different motions (contraction, expansion, bending, fragmentation, hopping, curling, and twisting) are appearing at the forefront of smart materials research. The photomechanical motions of these single crystals during irradiation are triggered by solid-state photochemical reactions and accompanied by phase transformation. This Minireview summarizes recent developments in growing research into photoresponsive molecular crystals. The basic mechanisms of different kinds of photomechanical materials are described in detail; recent advances in photomechanical crystals for promising applications as smart materials are also highlighted.

18.
Brain ; 142(3): 700-718, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30689733

RESUMO

Ectonucleotidase-mediated ATP catabolism provides a powerful mechanism to control the levels of extracellular adenosine. While increased adenosine A2A receptor (A2AR) signaling has been well-documented in both Parkinson's disease models and patients, the source of this enhanced adenosine signalling remains unclear. Here, we show that the ecto-5'-nucleotidase (CD73)-mediated adenosine formation provides an important input to activate A2AR, and upregulated CD73 and A2AR in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease models coordinatively contribute to the elevated adenosine signalling. Importantly, we demonstrate that CD73-derived adenosine-A2AR signalling modulates microglial immunoresponses and morphological dynamics. CD73 inactivation significantly attenuated lipopolysaccharide-induced pro-inflammatory responses in microglia, but enhanced microglia process extension, movement and morphological transformation in the laser injury and acute MPTP-induced Parkinson's disease models. Limiting CD73-derived adenosine substantially suppressed microglia-mediated neuroinflammation and improved the viability of dopaminergic neurons and motor behaviours in Parkinson's disease models. Moreover, CD73 inactivation suppressed A2AR induction and A2AR-mediated pro-inflammatory responses, whereas replenishment of adenosine analogues restored these effects, suggesting that CD73 produces a self-regulating feed-forward adenosine formation to activate A2AR and promote neuroinflammation. We further provide the first evidence that A2A enhanced inflammation by antagonizing dopamine-mediated anti-inflammation, suggesting that the homeostatic balance between adenosine and dopamine signalling is key to microglia immunoresponses. Our study thus reveals a novel role for CD73-mediated nucleotide metabolism in regulating neuroinflammation and provides the proof-of-principle that targeting nucleotide metabolic pathways to limit adenosine production and neuroinflammation in Parkinson's disease might be a promising therapeutic strategy.

19.
BMC Genomics ; 20(1): 37, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30642246

RESUMO

BACKGROUND: Cryptosporidium parvum is an important zoonotic parasitic disease worldwide, but the molecular mechanisms of the host-parasite interaction are not fully understood. Noncoding microRNAs (miRNAs) are considered key regulators of parasitic diseases. Therefore, we used microarray, qPCR, and bioinformatic analyses to investigate the intestinal epithelial miRNA expression profile after Cryptosporidium parvum infection. RESULTS: Twenty miRNAs were differentially expressed after infection (four upregulated and 16 downregulated). Further analysis of the differentially expressed miRNAs revealed that many important cellular responses were triggered by Cryptosporidium parvum infection, including cell apoptosis and the inflammatory and immune responses. CONCLUSIONS: This study demonstrates for the first time that the miRNA expression profile of human intestinal epithelium cells is altered by C. parvum infection. This dysregulation of miRNA expression may contribute to the regulation of host biological processes in response to C. parvum infection, including cell apoptosis and the immune responses. These results provide new insight into the regulatory mechanisms of host miRNAs during cryptosporidiosis, which may offer potential targets for future C. parvum control strategies.


Assuntos
Criptosporidiose/genética , Cryptosporidium parvum , Interações Hospedeiro-Parasita , MicroRNAs , Transcriptoma , Linhagem Celular Tumoral , Criptosporidiose/parasitologia , Regulação para Baixo , Redes Reguladoras de Genes , Humanos , Mucosa Intestinal/citologia , Ativação Transcricional , Regulação para Cima
20.
Adv Mater ; : e1805148, 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30480344

RESUMO

Antibodies have emerged as a fast-growing category of biopharmaceuticals that have been widely applied in scientific research, medical diagnosis, and disease treatment. However, many antibodies and other biopharmaceuticals display inferior biophysical properties, such as low stability and a propensity to undergo aggregation. Enhancing the stability of biopharmaceuticals is essential for their wide applications. Here, a facile in vitro protective coating strategy based on metal-organic frameworks (MOFs) is proposed to efficiently protect antibodies against perturbation environments and quickly recover them from the MOFs before usage, which avoids introducing protective additives into the body, which may cause biosafety risks. The protected antibodies exhibit extraordinary thermal, chemical, and mechanical stabilities, and they can survive for long-term storage (>3 weeks) under severe temperature variation (4 ↔ 50 °C) at a fast ramp rate (25 °C min-1 ). More importantly, the encapsulated antibodies can be easily released as quickly as 10 s with high efficiency (≈100%) to completely remove the MOFs before use. This study paves a new avenue for the facile preparation and storage of biopharmaceuticals represented by antibodies under ambient or perturbation conditions, which may greatly broaden and promote the applications of both MOFs and biopharmaceuticals.

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