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1.
Chem Commun (Camb) ; 55(95): 14335-14338, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31720600

RESUMO

A syn-atropisomer of naphthalene diimide as a highly preorganized precursor was used to construct a type of trapezoid-shape macrocycle, namely 'trapezoid' molecular boxes (TBox). As supramolecular hosts, TBox can bind electron-rich guests and selectively recognize free tryptophan and tryptophanyl residues from 20 standard amino acids.


Assuntos
Imidas/química , Compostos Macrocíclicos/química , Naftalenos/química , Triptofano/análise
2.
Chem Commun (Camb) ; 55(69): 10257-10260, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31393470

RESUMO

A robust microporous material (FJI-H19), which is constructed from distorted cuboctahedral cages and distorted octahedral cages, has been successfully synthesized. FJI-H19 possesses good thermal and water stability as well as highly selective adsorption of C3 and C4 hydrocarbons over CH4 under ambient conditions. More importantly, the high selectivities for the separation of CH4/C3 or C4 mixtures (85/15) have not only been estimated by ideal adsorbed solution theory (IAST) but also definitely confirmed by breakthrough experiments.

3.
Inorg Chem ; 58(18): 11983-11987, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31310509

RESUMO

Herein, a microporous NbO-type framwork (FJI-H23) that showed outstanding surface area (3740.4 m2·g-1) was fabricated by utilizing an azobenzene-derived carboxylate ligand. As anticipated, FJI-H23 can store 2.35 wt % H2 at 77 K up to 1 bar. Furthermore, FJI-H23 exhibits high-capacity storage of C2 and C3 hydrocarbons at room temperature. Especially, the uptake amount of C3H8 is 325.76 cm3·g-1 at 298 K, which represents the new record of C3H8 adsorption capacity in the MOFs materials. In addition, FJI-H23 exhibits excellent gravimetric total uptake of 332 cm3·g-1 at 298 K and 65 bar.

4.
J Glob Antimicrob Resist ; 19: 188-191, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31121335

RESUMO

OBJECTIVES: The aim of this study was to investigate the molecular mechanisms conferring amikacin (AMK) resistance in Mycobacterium abscessus clinical isolates. METHODS: A total of 194M. abscessus clinical isolates were collected from patients with pulmonary disease during the period 2012-2017. AMK susceptibility was determined by the broth microdilution method. Whole-genome data were used for identification of mutations in resistance-associated genes. Quantitative reverse transcription PCR (qRT-PCR) was performed to measure the gene transcriptional level. RESULTS: AMK showed high in vitro killing activity against M. abscessus, with an MIC50 of 8mg/L and an MIC90 of 16mg/L. Five isolates (2.6%) were resistant to AMK (MIC>1024mg/L), of which four (80.0%) harboured a resistance-associated rrs mutation A1408G. qRT-PCR analysis showed that most of the AMK-resistant isolates (4/5; 80.0%) overexpressed the transcriptional regulator gene whiB7 and the multidrug-efflux transporter gene tap. However, overexpression of the aminoglycoside-modifying enzyme gene eis2 was only observed in one (20.0%) AMK-resistant isolate. CONCLUSION: The AMK resistance rate in M. abscessus clinical isolates in this study was low (2.6%). The A1408G mutation in rrs and overexpression of WhiB7 and Tap were the predominant mechanisms of AMK resistance in M. abscessus.

5.
Dalton Trans ; 48(17): 5527-5533, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30946410

RESUMO

Herein, an anionic indium-organic framework, FJI-H21, was successfully prepared using an azobenzene-derivated tetra-carboxylate ligand, which had well-shaped honeycomb-like hexagonal channels along the crystallographic b-axis and trapezoidal window-like one-dimensional channels along the crystallographic c-axis. Due to its intrinsic microporosity, FJI-H21 demonstrated highly selective storage of C2-C3 hydrocarbons over CH4 under ambient conditions; furthermore, the selectivities for equimolar light hydrocarbons/CH4, estimated by the ideal adsorbed solution theory (IAST), indicated that FJI-H21 could efficiently separate C2-C3 hydrocarbons from CH4. However, FJI-H21 could also selectively adsorb cationic dyes, such as methylene blue (MB), ethyl violet (EV) and cation red (GTL) from anionic or neutral dyes with high uptake, rapid adsorption rate, and good recyclability; especially, using microcrystalline materials developed by fast synthesis, the adsorption rate for cationic dyes was significantly improved by 100-fold as compared to that of block crystals. The abovementioned results indicate that the sizes of the samples have an important influence on their adsorption performance.

6.
J Am Chem Soc ; 141(7): 3129-3136, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30689379

RESUMO

The predictable topologies and designable structures of metal-organic frameworks (MOFs) are the most important advantages for this emerging crystalline material compared to traditional porous materials. However, pore-environment engineering in MOF materials is still a huge challenge when it comes to the growing requirements of expanded applications. A useful method for the regulation of pore-environments, linker installation, has been developed and applied to a series of microporous MOFs. Herein, employing PCN-700 and PCN-608 as platforms, ionic linker installation was successfully implemented in both microporous and mesoporous Zr-based MOFs to afford a series of ionic frameworks. Selective ionic dye capture results support the ionic nature of these MOFs. The mesopores in PCN-608 are able to survive after installation of the ionic linkers, which is useful for ion exchange and further catalysis. To illustrate this, Ru(bpy)32+, a commonly used photoactive cation, was encapsulated into the anionic mesoporous PCN-608-SBDC via ion exchange. Photocatalytic activity of Ru(bpy)3@PCN-608-SBDC was examined by aza-Henry reactions, which show good catalytic performance over three catalytic cycles.

7.
Mol Genet Genomics ; 294(2): 493-500, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30604070

RESUMO

Congenital anomalies of the kidney and urinary tract (CAKUT) are a wide range of congenital structural renal defects. CAKUT is the leading cause of chronic renal failure and end-stage renal disease in children. Studies in humans and animal models have confirmed the large genetic contribution to CAKUT. The previous evidence suggested that human TBX6 coding mutations might cause CAKUT via gene-dosage insufficiency. However, the potential involvement of TBX6 noncoding mutations in CAKUT remains to be elucidated. Here, we described DNA sequencing and copy-number analysis of TBX6 in 269 Chinese subjects with CAKUT. Interestingly, we identified two heterozygous noncoding variants of TBX6 in sporadic subjects with CAKUT: one is c.769-7delT, from a subject with duplex renal and collecting system, and the other is a 3' untranslated region (3'-UTR) variant (c.1392C>T) from a subject with unilateral renal hypoplasia. These two TBX6 noncoding variants are novel and extremely rare, respectively, in human populations archived in the ExAC database. The mini-gene splicing assay showed that the TBX6 c.769-7delT variant significantly reduced the splicing efficiency of TBX6 intron 5 when compared to the wild-type control. In this work, we identified a novel splicing variant of TBX6 in human CAKUT. Our experimental observations suggested that the TBX6 noncoding variant can affect gene expression and may potentially be involved in human CAKUT.


Assuntos
Sítios de Splice de RNA/genética , Análise de Sequência de DNA , Proteínas com Domínio T/genética , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/genética , Adolescente , Criança , Feminino , Humanos , Rim/fisiopatologia , Masculino , Mutação , Fenótipo , Anormalidades Urogenitais/fisiopatologia , Refluxo Vesicoureteral/fisiopatologia , Sequenciamento Completo do Exoma
8.
Nat Commun ; 9(1): 4941, 2018 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-30467391

RESUMO

Research into stimuli-responsive controlled self-assembly and reversible transformation of molecular architectures has received much attention recently, because it is important to understand and reproduce this natural self-assembly behavior. Here, we report two coordination nanocapsules with variable cavities: a contracted octahedral V24 capsule and an expanded ball-shaped V24 capsule, both of which are constructed from the same number of subcomponents. The assemblies of these two V24 capsules are solvent-controlled, and capable of reversible conversion between contracted and expanded forms via control of the geometries of the metal centers by association and dissociation with axial water molecules. Following such structural interconversions, the magnetic properties are significantly changed. This work not only provides a strategy for the design and preparation of coordination nanocapsules with adaptable cavities, but also a unique example with which to understand the transformation process and their structure-property relationships.

9.
J Am Chem Soc ; 140(39): 12328-12332, 2018 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-30227706

RESUMO

Multicomponent metal-organic frameworks (MOFs) promise the precise placement of synergistic functional groups with atomic-level precision, capable of promoting fascinating developments in basic sciences and applications. However, the complexity of multicomponent systems poses a challenge to their structural design and synthesis. Herein, we show that linkers of low symmetry can bring new opportunities to the construction of multicomponent MOFs. A carbazole-tetracarboxylate linker of  C s point group symmetry was designed and combined with an 8-connected Zr6 cluster to generate a low-symmetry MOF, PCN-609. PCN-609 contains coordinatively unsaturated Zr sites arranged within a lattice with three crystallographically distinct pockets, which can accommodate linear linkers of different lengths. Sequential linker installation was carried out to postsynthetically insert three linear linkers into PCN-609, giving rise to a quinary MOF. Functionalization of each linker from the quinary MOF system creates multivariate pore environments with unprecedented complexity.

10.
Zhongguo Zhong Yao Za Zhi ; 42(15): 2939-2945, 2017 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-29139261

RESUMO

Sichuan safflower (Carthamus tinctorius) is a traditional Chinese medicine for promoting blood circulation and removing blood stasis. In this paper, taking Sichuan province as an example, based on TM image, digital elevation model (DEM), meteorology, soil and other data, and using remote sensing and GIS technology to extract grassland, elevation, temperature and precipitation, soil and other influencing factors, the spatial distribution of the suitability of safflower was studied, and the field investigation was carried out. The results indicate that Sichuan safflower resources are mainly concentrated in the eastern and northeastern parts of Sichuan, and the suitable distribution area is about 6 277.14 km2. The area of suitable area of Dazhou is 1 143.45 km², which is suitable for the province area of 18.22%. From the county point of view, the suitable area of Dachuan is about 507.15 km², and accounting for 17.9% of county. In addition, Naxi, Qingshen, Jiangan and other 12 counties of the suitable area of more than 100 km², and accounted for more than 10% of the county. The results of remote sensing and GIS analysis are in accordance with the real area of Sichuan safflower resources. It is feasible to find out the area suitable for the growth of Sichuan safflower by 3S technologies. It can provide a scientific basis for the monitoring and development of Chinese herbal resources.


Assuntos
Carthamus tinctorius/crescimento & desenvolvimento , Plantas Medicinais/crescimento & desenvolvimento , China , Medicamentos de Ervas Chinesas , Sistemas de Informação Geográfica , Medicina Tradicional Chinesa , Solo , Telemetria , Temperatura Ambiente
11.
Int J Environ Health Res ; 27(6): 487-497, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28994318

RESUMO

The aim of this study was to investigate the accumulation characteristics of tungsten (W) by different indica rice cultivars from the soil and to assess the potential risks to human health via dietary intake of W in rice consumption. A total of 153 rice (ear) samples of 15 cultivars and the corresponding surface soil samples were collected from 7 cities in Fujian Province of southeastern China. The available soil W were extracted using H2C2O4·2H2O-(NH4)2C2O4·H2O at pH 3.3). Results showed that the total soil W ranged from 2.03 mg kg-1 to 15.34 mg kg-1 and available soil W ranged from 0.03 mg kg-1 to 1.61 mg kg-1. The W concentration in brown rice varied from 7 µg kg-1 to 283 µg kg-1 and was significantly correlated with the available soil W. The highest mean TFavail (transfer factor based on available soil W) was 0.91 for Te-you 627 (hybrid, indica rice), whereas the lowest was 0.08 for Yi-you 673 (hybrid, indica rice). The TFavail decreased with the increase in available soil W, clay content, and cation exchange capacity. The consumption of the brown rice produced from the investigated areas in some cultivars by the present study may cause risks to human health.


Assuntos
Oryza/metabolismo , Poluentes do Solo/farmacocinética , Tungstênio/farmacocinética , Disponibilidade Biológica , Monitoramento Ambiental , Contaminação de Alimentos , Humanos , Solo/química , Poluentes do Solo/química , Tungstênio/química
12.
Angew Chem Int Ed Engl ; 56(46): 14622-14626, 2017 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-28990352

RESUMO

A series of flexible MOFs (PCN-605, PCN-606, and PCN-700) are synthesized and applied to reversible bromine encapsulation and release. The chemical stability of these Zr-MOFs ensures the framework's integrity during the bromine adsorption, while the framework's flexibility allows for structural adaptation upon bromine uptake to afford stronger host-guest interactions and therefore higher bromine adsorption capacities. The flexible MOFs act as bromine-nanocontainers which elongate the storage time of volatile halides under ambient conditions. Furthermore, the bromine pre-adsorbed flexible MOFs can be used as generic bromine sources for bromination reactions giving improved yields and selectivities under ambient conditions when compared with liquid bromine.

13.
J Am Chem Soc ; 139(46): 16939-16945, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29073358

RESUMO

Ligands with flexible conformations add to the structural diversity of metal-organic frameworks but, at the same time, pose a challenge to structural design and prediction. Representative examples include Zr-tetracarboxylate-based MOFs, which afford assorted structures for a wide range of applications, but also complicate the structural control. Herein, we systematically studied the formation mechanism of a series of (4,8)-connected Zr-tetracarboxylate-based MOFs by altering the substituents on different positions of the organic linkers. Different ligand rotamers give rise to three types of structures with flu, scu, and csq topologies. A combination of experiment and molecular simulation indicate that the steric hindrance of the substituents at different positions dictates the resulting MOF structures. Additionally, the controllable formation of different structures was successfully implemented by a combination of linkers with different steric effects at specific positions.

14.
Adv Mater ; 29(42)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28960582

RESUMO

Network structures based on Star-of-David catenanes with multiple superior functionalities have been so far elusive, although numerous topologically interesting networks are synthesized. Here, a metal-organic framework featuring fused Star-of-David catenanes is reported. Two triangular metallacycles with opposite handedness are triply intertwined forming a Star-of-David catenane. Each catenane fuses with its six neighbors to generate a porous twofold intercatenated gyroid framework. The compound possesses exceptional stability and exhibits multiple functionalities including highly selective CO2 capture, high proton conductivity, and coexistence of slow magnetic relaxation and long-range ordering.

15.
Sci Rep ; 7(1): 9443, 2017 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-28842695

RESUMO

The combined toxic effects of copper (Cu) and cobalt (Co) were predicted using the biotic ligand model (BLM) for different concentrations of magnesium (Mg2+) and pH levels, with parameters derived from Cu-only and Co-only toxicity data. The BLM-based toxic unit (TU) approach was used for prediction. Higher activities of Mg2+ linearly increased the EC50 of Cu and Co, supporting the concept of competitive binding of Mg2+ and metal ions in toxic action. The effects of pH on Cu and Co toxicity were related not only to free Cu2+ and Co2+ activity, respectively, but also to inorganic metal complexes. Stability constants for the binding of Cu2+, CuHCO3+, CuCO3(aq), CuOH+, Mg2+, Co2+, CoHCO3+ and Mg2+ with biotic ligands were logK CuBL 5.87, [Formula: see text] 5.67, [Formula: see text] 5.44, logK CuOHBL 5.07, logK MgBL 2.93, logK CoBL 4.72, [Formula: see text] 5.81 and logK MgBL 3.84, respectively. The combinations of Cu and Co showed additive effects under different conditions. When compared with the FIAM-based TU model (root mean square error [RMSE = 16.31, R 2 = 0.84]), the BLM-based TU model fitted the observed effects better (RMSE = 6.70, R 2 = 0.97). The present study supports the BLM principles, which indicate that metal speciation and major cations competition need to be accounted for when predicting toxicity of both single metals and mixtures of metals.


Assuntos
Cobalto/toxicidade , Cobre/toxicidade , Magnésio/metabolismo , Modelos Biológicos , Raízes de Plantas/fisiologia , Triticum/fisiologia , Cátions/química , Grão Comestível , Concentração de Íons de Hidrogênio , Ligantes , Magnésio/química
16.
Chem Commun (Camb) ; 53(69): 9598-9601, 2017 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-28809411

RESUMO

Herein, an unprecedented monomeric bowl-like coordination complex, Ti12PgC3 (PgC3 = C-propylpyrogallol[4]arene), has been successfully synthesized. To the best of our knowledge, Ti12PgC3 not only presents the first pyrogallol[4]arene-based titanium coordination complex, but also the highest nuclearity titanium coordination complex in the metal-calixarene system. In addition, this titanium coordination complex can effectively degrade the methylene blue (MB) dye under sunlight.

17.
Angew Chem Int Ed Engl ; 56(8): 2101-2104, 2017 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-28090721

RESUMO

A robust hydrogen-bonded organic framework HOF-TCBP (H4 TCBP=3,3',5,5'-tetrakis-(4-carboxyphenyl)-1,1'-biphenyl) has been successfully constructed and structurally characterized. It possesses a permanent 3D porous structure with a 5-fold interpenetrated dia topological network. This activated HOF-TCBP has a high BET surface area of 2066 m2 g-1 and is capable of highly selective adsorption and separation of light hydrocarbons under ambient conditions. It shows excellent thermal stability, as demonstrated by PXRD experiments and N2 adsorption tests. Practical use of HOF-TCBP is facilitated by the ease of its preparation and renewal through rotary evaporation.

18.
Zhongguo Zhong Yao Za Zhi ; 42(22): 4395-4401, 2017 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-29318841

RESUMO

Research on predictive distribution and planting GAP of Cyathula officinalis in China is helpful to provide scientific basis for its protection and planting popularization. According to the data in 63 distribution sites and 49 ecological variables, using MaxEnt ecological niche model and 3S technology, we performed a quantitative analysis of suitable distribution and planting GAP of C. officinalis in China. Our results show that: ① the area of suitable distribution of C. officinalis is about 634 385.80 km² in total, and mainly in Northeastern and Southeastern Sichuan, Northern and Southeastern Yunnan, Western and Southwestern Guizhou, Southwestern and Northeastern Chongqing, Southwestern Shaanxi, Southeastern Gansu, Western Guangxi, Southeastern Tibet. ② The main ecological factors determining the potential distribution are precipitation, altitude, minimum temperature of coldest month, soil type, monthly mean temperature. ③ The planting GAP region are mainly in Guangyuan, Mianyang, Ya'an, Leshan, Liangshan, Panzhihua of Sichuan province, Hanzhong of Shaanxi province, Dali, Nujiang, Chuxiong, Baoshan, Qujing, Wenshan of Yunnan province, southwestern autonomous prefecture in Guizhou province. The results are of great significance for realizing the growth environment, predicting the potential distribution and promoting planting popularization for C. officinalis.


Assuntos
Amaranthaceae/crescimento & desenvolvimento , Clima , Dispersão Vegetal , Altitude , China , Ecologia , Modelos Teóricos , Plantas Medicinais/crescimento & desenvolvimento , Solo , Tibet
19.
Nat Commun ; 7: 11564, 2016 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-27168321

RESUMO

Flexible porous materials generally switch their structures in response to guest removal or incorporation. However, the design of porous materials with empty shape-switchable pores remains a formidable challenge. Here, we demonstrate that the structural transition between an empty orthorhombic phase and an empty tetragonal phase in a flexible porous dodecatuple intercatenated supramolecular organic framework can be controlled cooperatively through guest incorporation and thermal treatment, thus inducing empty shape-memory nanopores. Moreover, the empty orthorhombic phase was observed to exhibit superior thermoelasticity, and the molecular-scale structural mobility could be transmitted to a macroscopic crystal shape change. The driving force of the shape-memory behaviour was elucidated in terms of potential energy. These two interconvertible empty phases with different pore shapes, that is, the orthorhombic phase with rectangular pores and the tetragonal phase with square pores, completely reject or weakly adsorb N2 at 77 K, respectively.

20.
Angew Chem Int Ed Engl ; 55(26): 7478-82, 2016 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-27145401

RESUMO

We demonstrate that three flexible MOFs termed FJI-H11-R (FJI-H=Hong's group in Fujian Institute of Research on the Structure of Matter, R=Me, Et, (i) Pr) can reversibly respond to temperature and solvents via structural transformations, which can be visualized by in situ single-crystal X-ray snapshot analyses. FJI-H11-R exhibit colossal anisotropic thermal expansion, with a record-high uniaxial positive thermal-expansion coefficient of 653.2×10(-6)  K(-1) observed in FJI-H11-Me. Additionally, large c-axial shrinkage of 32.4 % is also observed during desolvation. The stimuli-responsive mechanism reveals the structural evolutions are related to the rotations and deformations of the organic linkers.

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