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1.
Front Neurol ; 15: 1375587, 2024.
Article in English | MEDLINE | ID: mdl-39036634

ABSTRACT

Background: Many systematic reviews (SRs) and meta-analysis (MAs) have reported the efficacy of acupuncture treatment for primary trigeminal neuralgia (PTN), but the quality of evidence is unknown and therefore needs to be evaluated comprehensively. Methods: Eight electronic databases were searched from their inception until January 5, 2024. The methodological quality, reporting quality, and risk of bias of the included SRs were assessed by the assessment of multiple systematic reviews 2 (AMSTAR-2), the Risk of Bias in Systematic Reviews (ROBIS) tool, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The quality of evidence for outcome measures was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Results: We identified 13 SRs/MAs met inclusion criteria. According to the results of the AMSTAR-2, six were rated as critically low quality and seven as low quality. According to ROBIS assessment, 8 SRs/MAs were classified as low risk, and 5 SRs/MAs were found to be high risk. The PRISMA report still has some reporting deficiencies in aspects such as protocol and registration, search strategy, risk of bias, additional analyzes and funding. According to the GRADE system, no high-quality evidence was found, 1 was of moderate quality, 4 were of low quality, and 8 were of critical low quality. Conclusion: Based on the evidence collected, acupuncture shows promise as a treatment for PTN patients. However, it is important to note that the included SRs/MAs generally have low methodological quality and evidence quality. Therefore, caution must be exercised when interpreting this conclusion. To enhance future research in this area, it is recommended to adequately report methodological details and adhere to guidelines for conducting SRs/MAs.Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42024499280.

2.
Huan Jing Ke Xue ; 45(6): 3661-3670, 2024 Jun 08.
Article in Chinese | MEDLINE | ID: mdl-38897785

ABSTRACT

The impact of microplastics (MPs) as a new type of pollutant on water pollution has become a research hotspot. To explore the response relationship between the abundance of MPs and nitrogen metabolism function in a freshwater environment, Lake Ulansuhai was used as the research object; the abundance of MPs in the water was detected using a Zeiss microscope, and the distribution characteristics of nitrogen metabolism functional bacteria and functional genes in the water were analyzed using metagenomics sequencing. The correlation analysis method was used to explore the relationship between the abundance of MPs and nitrogen metabolism functional microorganisms and nitrogen metabolism functional genes. The results showed that the presence of MPs in freshwater environments had a higher impact on Cyanobacteria and Firmicutes as the dominant phyla, and the presence of MPs promoted their enrichment and growth. Among the dominant bacterial genera, MPs promoted the growth of Mycobacterium and inhibited Candidatus_Planktopila more significantly, further indicating that in freshwater environments, MPs affected normal nitrogen metabolism by affecting microbial communities, and pathways such as carbon and nitrogen fixation and denitrification were important pathways for MPs to affect nitrogen metabolism. From the perspective of nitrogen metabolism functional genes, it was found that the abundance of MPs significantly affected some functional genes during nitrification (pmoA-amoA, pmoB-amoB, and pmoC-amoC), denitrification (nirK and napA), and dissimilatory nitrate reduction (nrfA) processes (P < 0.05). Moreover, the influence of MPs abundance on different functional genes in the same pathway of nitrogen metabolism varied, making the impact of MPs on aquatic environments very complex; thus, its harm to the water environment cannot be underestimated.


Subject(s)
Bacteria , Microplastics , Nitrogen , Water Pollutants, Chemical , Nitrogen/metabolism , Water Pollutants, Chemical/metabolism , Bacteria/metabolism , Bacteria/genetics , Bacteria/classification , Water Microbiology , Cyanobacteria/metabolism , Cyanobacteria/genetics , Lakes/microbiology , China , Fresh Water , Environmental Monitoring
3.
Angew Chem Int Ed Engl ; 63(23): e202403156, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38566540

ABSTRACT

Among the intriguing bicontinuous self-assembled structures, the gyroid cubic is the most ubiquitous. It is found in block and star polymers, surfactants with or without solvent, in thermotropic liquid crystals with end- or side-chains, and in biosystems providing structural color and modelling cell mitosis. It contains two interpenetrating networks of opposite chirality and is thus achiral if, as usual, the content of the two nets is the same. However, we now find that this is not the case for strongly chiral compounds. While achiral molecules follow the opposite twists of nets 1 and 2, molecules with a chiral center in their rod-like core fail to follow the 70° twist between junctions in net 2 and instead wind against it by -110° to still match the junction orientation. The metastable chiral gyroid is a high-entropy high-heat-capacity mesophase. The homochirality of its nets makes the CD signal of the thienofluorenone compounds close to that in the stable I23 phase with 3 isochiral nets.

4.
ACS Macro Lett ; 13(5): 550-557, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38634712

ABSTRACT

Highly ordered, network-nanostructured polymers offer compelling geometric features and application potential. However, their practical utilization is hampered by the restricted accessibility. Here, we address this challenge using commercial Pluronic surfactants with a straightforward modification of tethering polymerizable groups. By leveraging lyotropic self-assembly, we achieve facile production of double-gyroid mesophases, which are subsequently solidified via photoinduced cross-linking. The exceptionally ordered periodicities of Ia3d symmetry in the photocured polymers are unambiguously confirmed by synchrotron small-angle X-ray scattering (SAXS), which can capture single-crystal-like diffraction patterns. Electron density maps reconstructed from SAXS data complemented by transmission electron microscopy analysis further elucidate the real-space gyroid assemblies. Intriguingly, by tuning the cross-linking through thiol-acrylate chemistry, the mechanical properties of the polymer are modulated without compromising the integrity of Ia3d assemblies. The 3-D percolating gyroid nanochannels demonstrate an ionic conductivity that surpasses that of disordered structures, offering promising prospects for scalable fabrication.

5.
Front Aging Neurosci ; 16: 1383278, 2024.
Article in English | MEDLINE | ID: mdl-38572153

ABSTRACT

Objective: Alzheimer's disease (AD) is a prevalent neurodegenerative condition that significantly impacts both individuals and society. This study aims to evaluate the effectiveness of repetitive transcranial magnetic stimulation (rTMS) as a treatment for AD by summarizing the evidence from systematic reviews (SRs) and meta-analyses (MAs). Methods: SRs/MAs of rTMS for AD were collected by searching Embase, Web of Science, Cochrane Library, PubMed, CNKI, VIP, Sino-Med, and Wanfang databases. The search was conducted from database creation to January 23, 2024. Methodological quality, reporting quality and risk of bias were assessed using the Assessing Methodological Quality of Systematic Reviews 2 (AMSTAR-2), Risk of Bias in Systematic Reviews (ROBIS) tool and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). In addition, the quality of evidence for outcome measures was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Results: Eight SRs/MAs included in this study met the inclusion criteria. Based on the AMSTAR-2, 4 of the SRs/MA were classified as low quality, while the remaining 4 were deemed to be of very low quality. The PRISMA analysis revealed that out of the 27 items reporting, 16 achieved full reporting (100%). However, there were still some deficiencies in reporting, particularly related to protocol and registration, search strategy, risk of bias, and additional analysis. The ROBIS tool indicated that only 3 SRs/MAs had a low risk of bias. The GRADE assessment indicated that 6 outcomes were of moderate quality (18.75%), 16 were of low quality (50%), and 10 were classified as very low quality (31.25%). Conclusion: Based on the evidence collected, rTMS appears to be effective in improving cognitive function in AD patients, although the methodological quality of the SRs/MAs reduces the reliability of the conclusions and the overall quality is low. However, based on the available results, we still support the value of rTMS as an intervention to improve cognitive function in AD. In future studies, it is necessary to confirm the efficacy of rTMS in AD patients and provide more reliable and scientific data to contribute to evidence-based medicine.

6.
Inorg Chem ; 63(8): 3637-3641, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38341868

ABSTRACT

Two unique 22-core sandwich {[Mn6Mo6O37]Ln3[MnMo6O24]} (Ln = La or Pr) units have been assembled, featuring an undisclosed {Mn6Mo6} cluster. This assembly is subsequently integrated into two three-dimensional polyoxometalate organic frameworks, which exhibit one-dimensional hydrophilic hexagonal channels formed by six intertwined 63 helical chains, leading to effective proton conduction primarily facilitated by an abundance of water molecules within the channels.

7.
Inorg Chem ; 62(48): 19749-19757, 2023 Dec 04.
Article in English | MEDLINE | ID: mdl-37983184

ABSTRACT

Lanthanide-containing polyoxometalate-based metal-organic frameworks (POMOFs) not only enjoy intriguing architectures but also have good application prospects as catalysts. Herein, three novel three-dimensional (3D) POMOFs with the formulas of {H[Ln3(2,6-pydc)2(H2O)10(MnMo9O32)]·2H2O}n (Ln = La(1), Pr(2), Nd(3)) have been synthesized based on Waugh-type [MnMo9O32]6- anions and pyridine-2,6-dicarboxylate (2,6-H2pydc). Compounds 1-3 are isomorphic, and there are two kinds of one-dimensional (1D) helical chains with opposite handedness staggered into two-dimensional (2D) layers. Interestingly, the coordinated L- and R-[MnMo9O32]6- anions are encapsulated in 1D chains with the same chirality and are further expanded into 3D structures. The catalytic tests indicate that compounds 1-3 exhibit high-efficiency heterogeneous catalytic activity in the oxidative desulfurization reaction for catalyzing the oxidation of sulfides to sulfoxides using tert-butyl hydrogen peroxide (TBHP) as the oxidant. Moreover, a series of control experiments have been conducted to investigate the influence of various parameters such as temperature, time, solvent, catalyst, and substrate on the reaction. Significantly, compound 2, as an example, exhibits good reusability and structural stability in the oxidative desulfurization reaction. It is worth noting that investigations on the oxidative desulfurization of [MnMo9O32]6- anions are scarce. Moreover, their electrochemical properties are also explored.

8.
J Am Chem Soc ; 145(31): 17443-17460, 2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37523689

ABSTRACT

The recently discovered orthorhombic liquid crystal (LC) phase of symmetry Fddd is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping. Although pure R and S enantiomers form only a strongly chiral hexagonal columnar LC phase (Colh*), the racemic mixture forms a highly ordered Fddd phase with 4 right- and 4 left-handed twisted ribbon-like columns traversing its large unit cell. In that structure, the two enantiomers locally deracemize and self-sort into the columns of their preferred chirality. The twisted ribbons in Fddd, with a 7.54 nm pitch, consist of stacked rafts, each containing ∼2 side-by-side molecules, the successive rafts rotated by 17°. In contrast, an analogous achiral compound forms only the columnar phase. The multiple methods used gave a comprehensive picture and helped in-depth understanding not only of the Fddd phase but also of the "parachiral" Colh* in pure enantiomers with irregular helicity, whose chirality is compared to the magnetization of a paramagnet in a field. Unusual short-range ordering effects are also described. An explanation of these phenomena is proposed based on conformational analysis. Surprisingly, the isotropic-columnar transition is extremely fast, completing within ∼20 ms. A clear effect of phase on UV-vis absorption and emission is observed.

9.
Molecules ; 28(11)2023 May 27.
Article in English | MEDLINE | ID: mdl-37298858

ABSTRACT

Substituent-regulated cyclization of conjugated alkynes with acid catalysis was developed in this paper, and it provides a straightforward synthesis of cyclic-(E)-[3]dendralenes. Depending on the electronic effect of the aromatic ring pairing, a variety of phosphinyl quintuplet/hexa cyclo-[3]dendralenes with diverse substitution patterns are accessible, with good efficiency and high stereoselectivity. This self-cyclization process achieves the first precise construction of a phosphinylcyclo-(E)-[3]dendralene from conjugated alkynes to aromatization.


Subject(s)
Alkenes , Alkynes , Cyclization , Catalysis , Molecular Structure
10.
Shanghai Kou Qiang Yi Xue ; 32(5): 485-490, 2023 Oct.
Article in Chinese | MEDLINE | ID: mdl-38171517

ABSTRACT

PURPOSE: To analyze the morphological changes of the upper airway and related influencing factors in patients with skeletal Class Ⅲ malocclusion after bimaxillary surgery. METHODS: Twenty skeletal Class Ⅲ patients who underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy(BSSRO) for maxillary advancement and mandibular setback were selected. The patients received CT scans before(T0) and 3-6 months after surgery, and the images were reconstructed three-dimensionally with Dolphin Imaging 11.9 software. Changes in the volume, cross-sectional area, and landmarks of each soft and hard tissue of the airway were measured. Statistical analysis of the data was performed using SPSS 25.0 software package. RESULTS: The volume of nasopharyngeal airway increased after operation (P<0.05), and the volume of oropharyngeal airway decreased significantly(P<0.01). The cross-sectional area of the airway at the plane of the second cervical vertebra was significantly decreased (P<0.01), and the coronal and sagittal diameters were decreased(P<0.05). The change of nasopharyngeal airway volume was moderately positively correlated with the sagittal change of the posterior nasal spine (r=0.460, P<0.05), and the change of oropharynx and laryngopharyngeal airway volume was positively correlated with the vertical change of the midpoint of the soft palate(r=0.496, 0.696, P<0.05). The airway cross-sectional area in the second and third cervical vertebra planes and the sagittal diameter of the airway in the third cervical vertebra plane were positively correlated with the vertical changes of the midpoint of the soft palate(r=0.474, 0.629, 0.547, P<0.05). The change of airway cross-sectional area at the third cervical vertebra plane was moderately negatively correlated with the change of mandibular plane angle(r=-0.536, P<0.05). CONCLUSIONS: The volume and cross-sectional area of oropharyngeal airway in skeletal Class Ⅲ patients after bimaxillary surgery will decrease. However, the total upper airway volume doesn't change significantly. The changes in the upper airway are correlated with the changes in some soft and hard tissue landmarks.


Subject(s)
Malocclusion, Angle Class III , Pharynx , Humans , Malocclusion, Angle Class III/diagnostic imaging , Malocclusion, Angle Class III/surgery , Oropharynx/diagnostic imaging , Hypopharynx , Maxilla/diagnostic imaging , Maxilla/surgery , Cephalometry/methods , Osteotomy, Le Fort/methods , Osteotomy, Sagittal Split Ramus/methods , Cone-Beam Computed Tomography/methods
11.
Inorg Chem ; 61(35): 13829-13835, 2022 Sep 05.
Article in English | MEDLINE | ID: mdl-35998378

ABSTRACT

Water-stable proton-conducting materials owning excellent performances at ambient temperatures are currently one of the crucial challenges. Herein, four water-stable three-dimensional polyoxometalate-based rare-earth organic frameworks have been successfully synthesized and formulated as H{Ln4(L)2(H2O)21[Zr3(OH)3(PW9O34)2]}·15H2O (1-3) (Ln = La (1), Ce (2), Pr (3); L = 3,5-pyridine dicarboxylic acid), which are the first examples of MOFs constructed by a zirconium sandwiched polyoxoanion. There are abundant coordinated water molecules functionalizing the PrIII centers, and simultaneously, plenty of lattice water molecules are fitted into the channel of the framework. A continuous H-bonding network is found between the architectures and plays an important role in stabilizing the structure. Benefiting from the consecutive H-bonding networks, compounds 1-3 showed high proton conductivities at ambient temperature (up to 1.05 × 10-3 S·cm-1 under 98% RH) by a synergistic effect of the combined components.

12.
Sensors (Basel) ; 22(11)2022 May 25.
Article in English | MEDLINE | ID: mdl-35684616

ABSTRACT

In existing cryptographic key distribution (CKD) protocols based on computational ghost imaging (CGI), the interaction among multiple legitimate users is generally neglected, and the channel noise has a serious impact on the performance. To overcome these shortcomings, we propose a multi-party interactive CKD protocol over a public network, which takes advantage of the cascade ablation of fragment patterns (FPs). The server splits a quick-response (QR) code image into multiple FPs and embeds different "watermark" labels into these FPs. By using a CGI setup, the server will acquire a series of bucket value sequences with respect to different FPs and send them to multiple legitimate users through a public network. The users reconstruct the FPs and determine whether there is an attack in the public channel according to the content of the recovered "watermark" labels, so as to complete the self-authentication. Finally, these users can extract their cryptographic keys by scanning the QR code (the cascade ablation result of FPs) returned by an intermediary. Both simulation and experimental results have verified the feasibility of this protocol. The impacts of different attacks and the noise robustness have also been investigated.


Subject(s)
Computer Security , Renal Insufficiency, Chronic , Computers , Confidentiality , Diagnostic Imaging , Humans
13.
Biomed Pharmacother ; 149: 112799, 2022 May.
Article in English | MEDLINE | ID: mdl-35279011

ABSTRACT

Lupus nephritis (LN) is an autoimmune disease with multiple system involvement and is also one of the most serious forms of organ damage in systemic lupus erythematosus (SLE), which is mainly caused by the formation and deposition of immune complexes in glomeruli. More than 50% of SLE patients have clinical manifestations of renal damage. At present, the treatment of lupus nephritis is mainly based on glucocorticoids and immunosuppressants. However, due to adverse drug reactions and frequent recurrence or aggravation after drug reduction or withdrawal, the prognosis remains poor; thus, it is still one of the most important causes of end-stage renal failure. Therefore, new treatment strategies are urgently needed. This article aims to review the application of traditional Chinese medicine and natural extracts in the treatment of lupus nephritis to provide the basic mechanisms of treatment and a new treatment strategy with clear effects and high safety performance.


Subject(s)
Lupus Erythematosus, Systemic , Lupus Nephritis , Female , Humans , Kidney , Lupus Nephritis/drug therapy , Male , Medicine, Chinese Traditional , Plant Extracts
14.
Nat Commun ; 13(1): 384, 2022 01 19.
Article in English | MEDLINE | ID: mdl-35046396

ABSTRACT

Helical structures continue to inspire, prompted by examples such as DNA double-helix and alpha-helix in proteins. Most synthetic polymers also crystallize as helices, which relieves steric clashes by twisting, while keeping the molecules straight for their ordered packing. In columnar liquid crystals, which often display useful optoelectronic properties, overall helical chirality can be induced by inclusion of chiral chemical groups or dopants; these bias molecular twist to either left or right, analogous to a magnetic field aligning the spins in a paramagnet. In this work, however, we show that liquid-crystalline columns with long-range helical order can form by spontaneous self-assembly of straight- or bent-rod molecules without inclusion of any chiral moiety. A complex lattice with Fddd symmetry and 8 columns per unit cell (4 right-, 4 left-handed) characterizes this "antiferrochiral" structure. In selected compounds it allows close packing of their fluorescent groups reducing their bandgap and giving them promising light-emitting properties.

15.
Sensors (Basel) ; 21(22)2021 Nov 13.
Article in English | MEDLINE | ID: mdl-34833635

ABSTRACT

Ghost imaging is an indirect optical imaging technique, which retrieves object information by calculating the intensity correlation between reference and bucket signals. However, in existing correlation functions, a high number of measurements is required to acquire a satisfied performance, and the increase in measurement number only leads to limited improvement in image quality. Here, inspired by the gradient descent idea that is widely used in artificial intelligence, we propose a gradient-descent-like ghost imaging method to recursively move towards the optimal solution of the preset objective function, which can efficiently reconstruct high-quality images. The feasibility of this technique has been demonstrated in both numerical simulation and optical experiments, where the image quality is greatly improved within finite steps. Since the correlation function in the iterative formula is replaceable, this technique offers more possibilities for image reconstruction of ghost imaging.

16.
Ying Yong Sheng Tai Xue Bao ; 32(9): 3159-3166, 2021 Sep.
Article in Chinese | MEDLINE | ID: mdl-34658201

ABSTRACT

We analyzed soil water, nutrients, and yields in three different slope sites in the sloping farmland under Yuluxiang pear planted in the loess hilly region of Western Shanxi, across the growth periods and different soil depths. The results showed that: 1) The yield of pear was in the order of high slope site > middle slope site > low slope site. In high slope site, the yield was significantly correlated with soil water content (SWC), soil organic matter (SOM), available potassium (AK), with AK showing the most significant effect. The yield of pear in middle and low slope sites was significantly correlated with SWC, SOM, and total nitrogen (TN), with SWC having the most significant effect on yield. The contents of SWC, SOM, available phosphorus (AP) and TN in high slope site were higher than in middle and low slope sites, while AK was the highest in middle slope site. 2) Among different soil depths, soil nutrient contents were the highest within 0-20 cm soil layer, but the lowest within 20-40 cm soil layer. The SWC was significantly lower within 0-20 cm than the other soil layers and was the highest within 20-40 cm soil layer. 3) Among different growth periods, the contents of SOM, AP, and TN were the highest in flowering period, the SWC was the highest in fruiting period, and AK content was the highest in maturing period. It was suggested that in the future management of pear water and fertilizer in the region, more K fertilizer should be applied in the high slope sites in the flowering period, while N and P compound fertilizer should be applied in the fruiting period, to enhance irrigation in middle and low slope sites to decrease the limitation of water with 300 m3·hm-2. Our results could provide theoretical support and data refe-rence for planting precision irrigation and scientific fertilization of pear planted in loess hilly areas.


Subject(s)
Pyrus , Soil , Nutrients , Phosphorus , Water
17.
mSystems ; 6(4): e0015821, 2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34282934

ABSTRACT

The influence of human genetic variants on the vaginal bacterial traits (VBTs) of pregnant women is still unknown. Using a genome-wide association approach based on the 16S rRNA bacteriome analysis, a total of 72 host genetic variant (single nucleotide polymorphisms [SNPs], indels, or copy number variations [CNVs])-VBT associations were found that reached the genome-wide significance level (P < 5 × 10-8) with an acceptable genomic inflation factor λ of <1.1. The majority of these SNPs that reached the genome-wide significance level had a relatively low minor allele frequency (MAF), and only seven of them had MAFs greater than 0.05. rs303212, located at the IFIT1 gene on chromosome 10, was the most eye-catching variant, which had a genome-wide association with the relative abundance (RAB) of Actinobacteria and Bifidobacteriaceae and also had a suggestive association with the RAB of a few common vaginal bacteria including Actinobacteriota, Firmicutes, Lactobacillus, and Gardnerella vaginalis and the beta diversity weighted UniFrac (P < 1 × 10-5). The findings of the study suggest that the vaginal bacteriome may be influenced by a number of genetic variants across the human genome and that interferon signaling may have an important influence on vaginal bacterial communities during pregnancy. IMPORTANCE Knowledge about the influence of host genetics on the vaginal bacteriome in pregnancy is still limited. Although a number of environmental and behavioral factors may exert influences on the structure of vaginal bacterial communities, the vaginal bacteriome often undergoes a relatively fixed transition to a more stable and less diverse state as the menstrual cycle stops, which raises questions on the effects of human genetics. We utilized a genome-wide approach to identify the associations between genetic variants and multiple VBTs and performed enrichment analyses. The human genetics during pregnancy may be involved in multiple pathways. The results may disclose innate functional factors involved in shaping the vaginal bacteriome during pregnancy and provide insight into the establishment of specific strategies for prevention and clinical treatment of pregnancy complications.

18.
Macromol Rapid Commun ; 42(12): e2100115, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33960572

ABSTRACT

Gyroid-nanostructured all-solid polymer films with exceedingly high proton conductivity and low H2 gas permeability have been created via crosslinking polymerization of mixtures of a zwitterionic amphiphilic monomer and a polymerizable imide-type acid that co-organize into bicontinuous cubic liquid-crystalline phases. The gyroid nanostructures are visualized by reconstructing a 3D electron map from the synchrotron X-ray diffraction patterns. These films exhibit high proton conductivity of the order of 10-1 S cm-1 and extremely low H2 gas permeability of the order of 10-15 mol m m-2 s-1 Pa-1 . These properties can be ascribed to the presence of the ionic liquid-like layer along the gyroid minimal surface. Since these two characteristics are required for improving the performance of proton-exchange membrane fuel cells, the present membrane design represents a promising strategy for the development of advanced devices, pertinent to establishing sustainable energy sources.


Subject(s)
Nanostructures , Polymers , Electric Conductivity , Permeability , Protons
19.
Angew Chem Int Ed Engl ; 59(22): 8445-8450, 2020 May 25.
Article in English | MEDLINE | ID: mdl-32128958

ABSTRACT

We report a new molecular-design principle for creating double-gyroid nanostructured molecular assemblies based on atropisomerization. Ionic amphiphiles containing two imidazolium rings close to each other were designed and synthesized. NMR data revealed that the rotation of the imidazolium rings is restricted, with an activation energy as high as 63 kJ mol-1 in DMSO-d6 solution (DFT prediction for a model compound in the vacuum: 90-100 kJ mol-1 ). Due to the restricted rotation, the amphiphiles feature "double" atropisomeric axes in their ionic segments and form three stable atropisomers: meso, R, and S. These isomers co-organize into I a 3 ‾ d -type bicontinuous cubic liquid-crystalline mesophases through nanosegregation of the ionic and non-ionic parts. Considering the intrinsic characteristic of I a 3 ‾ d -type bicontinuous cubic structures that they are composed of intertwined right- and left-handed single gyroids, we propose that the simultaneous presence of both R- and S-atropisomers is an important contributor to the formation of double-gyroid structures.

20.
Opt Express ; 27(24): 35166-35181, 2019 Nov 25.
Article in English | MEDLINE | ID: mdl-31878690

ABSTRACT

Ghost imaging technologies acquire images through intensity correlation of reference patterns and bucket values. Among them, an interesting method named correspondence imaging can generate positive-negative images by only conditionally averaging reference patterns, but still requires full/over sampling to treat the ensemble average of bucket values as a selection criteria, causing a long acquisition time. Here, we propose a sequential-deviation ghost imaging approach, which can realize real-time reconstructions of positive-negative images with a high image quality close to that of differential ghost imaging. Since it is no longer necessary to compare with the ensemble average, this method can improve the real-time performance. An explanation of its essence is also given here. Both simulation and experimental results have demonstrated the feasibility of this technique. This work may complement the theory of ghost imaging.

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