POLYMER
·
2024
·
IF 4.1
Chunlei Xu,Hang Guo,Changzhu Lv,Wei Chen,Liangbin Li,Kunpeng Cui
Understanding on the structure and dynamics of poly(vinyl acetal)s is insufficient due to the complicated chemical structure and amorphous nature of this type of polymers. In this work, we investigate the effect of side group length on structure and dynamics heterogeneity at different length scales spanning from side group, segment, and polymer network by combing dynamic mechanical analysis (DMA), dielectric relaxation spectroscopy (DRS), solid-state NMR, and differential scanning calorimetry analysis (DSC). By increasing the length of acetal side group, its intrinsic dynamics slows down. Taking into account the scale of segment and networks, with the increase of acetal group length, the formation of cross-linking sites formed by the hydroxyl-rich domain is suppressed, the relaxation distribution of the segment widens, and the volume fraction of rigid component decreases. The effect of side group length on the structure and dynamics heterogeneity of poly(vinyl acetal)s at different scales results in significant changes in material properties such as the non-monotonic change in loss factor value (tan δ ) and a monotonous reduction in glass transition temperature ( T g ).
研究领域:
高分子化学
·
材料科学
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产品关联
DOI
高影响因子
iScience
·
2023
·
IF 5.8
Xuanlin Meng,Ping Xu,Fei Tao
Summary Synthetic biology, relying on Design-Build-Test-Learn (DBTL) cycle, aims to solve medicine, manufacturing, and agriculture problems. However, the DBTL cycle’s Learn (L) step lacks predictive power for the behavior of biological systems, resulting from the incompatibility between sparse testing data and chaotic metabolic networks. Herein, we develop a method, “RespectM,” based on mass spectrometry imaging, which is able to detect metabolites at a rate of 500 cells per hour with high efficiency. In this study, 4,321 single cell level metabolomics data were acquired, representing metabolic heterogeneity. An optimizable deep neural network was applied to learn from metabolic heterogeneity and a “heterogeneity-powered learning (HPL)” based model was trained as well. By testing the HPL based model, we suggest minimal operations to achieve high triglyceride production for engineering. The HPL strategy could revolutionize rational design and reshape the DBTL cycle.
研究领域:
合成生物学
·
代谢组学
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DOI
高影响因子
Materials
·
2015
·Vol. 8
·期 7
·4249-4257
·
IF 2.651
Cheng Song,Ruofan Du,Yongmei Zheng
Inspired by the high adhesiveness of the electrospun fiber, we propose a method to fabricate multi-scale heterogeneous hump-on-string fiber via the adsorption of nanoparticles, the NPCTi which is the hydrolysate of titanium tetrachloride (TiCl4) and the nanoparticles containing Al (NPCAl) which is produced by the hydrolysis of Trimethylaluminium (TMA, Al(CH3)3). The water collection efficiency of the fibers can be easily controlled via changing not only the size of the beads but also the ratio of the Ti and Al. In addition, we introduce a computational fluid dynamics (CFD) simulation to show the pressure distribution of on the surface of the fibers, which gives another explanation regarding the high water collection efficiency.Keywords:wet-induced assembly;heterogeneous;hump-on-string fiber
研究领域:
材料科学
·
仿生学
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产品关联
DOI
PubMed
高影响因子
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
·
2020
·Vol. 64
·期 3
·
IF 4.904
Zhiwei Lin,Zhangya Pu,Guangjian Xu,Bing Bai,Zhong Chen,Xiang Sun,Jinxin Zheng,Peiyu Li,Di Qu,Qiwen Deng,Zhijian Yu
This study aimed to evaluate the in vitro antimicrobial activity, heteroresistance emergence, and resistance mechanism of omadacycline (OMC) in clinical Enterococcus faecalis isolates from China. A total of 276 isolates were collected retrospectively in China from 2011 to 2015. The MICs of OMC, doxycycline (DOX), and minocycline (MIN) against E. faecalis were determined by broth microdilution. Tetracycline (TET)-specific resistance genes and multilocus sequence typing (MLST) of the isolates were investigated using PCR. The detection frequency of OMC heteroresistance in E. faecalis was evaluated with population analysis profiling (PAP). The mechanism of OMC heteroresistance and resistance in E. faecalis was examined by amplifying 30S ribosomal subunit genes, RNA sequencing (RNA-Seq), and in vitro recombination experiments. The OMC MICs of clinical E. faecalis isolates ranged from ≤0.06 to 1.0 mg/liter, and 42% of the E. faecalis isolates with an OMC MIC of 1.0 mg/liter were found to be sequence type 16 (ST16). Six OMC-heteroresistant isolates with MIC values of ≤0.5 mg/liter were detected among 238 E. faecalis isolates. The resistant subpopulations of heteroresistant isolates showed OMC MICs in the range of 2 to 4 mg/liter and were found without 30S ribosomal subunit gene mutations. Moreover, RNA sequencing and in vitro recombination experiments demonstrated that overexpression of a bone morphogenetic protein (BMP) family ATP-binding cassette (ABC) transporter substrate-binding protein, OG1RF_RS00630, facilitated OMC heteroresistance in E. faecalis. In conclusion, OMC exhibited better activity against clinical E. faecalis isolates from China than that of DOX or MIN, and overexpression of OG1RF_RS00630 in E. faecalis facilitated the development of OMC heteroresistance.
研究领域:
微生物学
·
感染病学
·
药理学
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DOI
PubMed
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-8
·
IF 14.919
Lei Yuting,Zhang Guihua,Zhang Qinglan,Yu Ling,Li Hua,Yu Haili,He Yi
Zeolitic imidazolate frameworks (ZIFs) are very useful as high-capacity iodine (I 2 ) adsorbents. The adsorption performance is usually probed by measuring a statistical average property over an entire sample consisting of a large number of ZIF particles, leaving the interparticle heterogeneity information among individuals. Here we report a dark-field microscopy (DFM) method to visualize gaseous I 2 adsorption on single ZIF-90 particles in situ and in real time. The adsorption of I 2 is found to alter the scattering spectrum of ZIF-90 particles, inducing a distinct color change from bluewhite to yellow. According to correlating the adsorption amount of gaseous I 2 with the change of B value from DFM images, we quantitatively image the adsorption process and estimate the related kinetic parameters at the single particle level. Single particle measurements clarify the large particle-to-particle heterogeneity in adsorption reactivity and significant adsorption activity improvement of ZIF-90 after introduction of linker defects, which provides a microscopic understanding of the structure-activity relationship. We further demonstrate the capacity of this strategy for studying gaseous I 2 adsorption on single ZIF-91 particle as a derivative of ZIF-90 to illustrate the generality.
研究领域:
材料科学
·
化学
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产品关联
DOI
PubMed
高影响因子
Membranes
·
2025
·Vol. 15
·期 5
·141
·
IF 3.6
Ning Li,Hongbo Xin,Keyu Deng
Outer membrane vesicles (OMVs) are extracellular vesicles secreted by Gram-negative bacteria with diameters of 20–250 nm. OMVs contain various biologically active substances from their parent bacteria, such as proteins, lipids, and nucleic acids.Escherichia coliNissle 1917 (EcN) is a Gram-negative probiotic that resides in the human intestine. EcN-derived OMVs are pivotal in modulating intestinal immune responses. However, few studies have addressed the heterogeneity of EcN-derived OMVs in terms of size, significantly limiting the research on their clinical applications. Currently, there are a lack of feasible methods for obtaining EcN-derived OMVs of different sizes. To address this knowledge gap, we developed a membrane filtration method to isolate EcN-derived OMVs of varying sizes. In this study, we first used gradient filtration to isolate high-purity EcN-derived OMVs and conducted a proteomic analysis. Subsequently, we used membrane filtration to separate the EcN-derived OMVs by size. We successfully obtained EcN-derived OMVs of three specific sizes: <50 nm, 50–100 nm, and 100–300 nm. We then performed proteomic analyses of these EcN-derived OMVs and compared their protein profiles. Finally, we compared the ability of each EcN-derived OMV type to induce RAW264.7 macrophages to secrete the pro-inflammatory factor interleukin (IL)-1β and the anti-inflammatory factor IL-10. The EcN-derived OMVs contained 646 different proteins overall; those of different sizes contained different protein types. Among them, the EcN-derived OMVs in the <50 nm group contained significantly fewer proteins (262 different types in total) than those in the 50–100 nm (1603 types) and 100–300 nm (1568 types) groups. Furthermore, the <50 nm group had fewer membrane proteins (40) than the 50–100 nm (215) and 100–300 nm (209) groups. We also found that RAW264.7 macrophages secreted different concentrations of IL-1β and IL-10 following co-incubation with the three EcN-derived OMV types. The 50–100 nm EcN-derived OMV group showed a stronger effect in terms of inducing inflammatory cytokine secretion compared to the other two groups. This study provides direct experimental evidence that EcN-derived OMVs of different sizes exhibit heterogeneous properties.
研究领域:
微生物学
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免疫学
·
蛋白质组学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Mengni Zhu,Huan Liu,Qiping Cao,Hao Zheng,Dang Xu,Haoyu Guo,Shumei Wang,Yao Li,Jinghui Zhou
Lignin shows great potential for carbon-based functional materials and composite material electronics. However, high heterogeneity, poor thermal stability, and low molecular weight limit the practical application of lignin for fiber-shaped lignin-based materials, especially in the field of supercapacitors with high energy storage devices. Herein, a simple modification and fractionation strategy is designed to obtain lignin for the preparation of high-performance lignin-based carbon fibers (CFs). The modification and fractionation process effectively increases the molecular weight and reduces the heterogeneity of lignin. The introduction of lignin with large molecular weight and low heterogeneity is conducive to reduce the carbon weight loss of the precursor fibers, maintain the morphology of lignin-based CFs, and then significantly improve the specific surface area and energy storage properties. The specific surface area and energy storage density of the obtained lignin-based CFs reach 2042.86 m2/g and 442.2 F/g, respectively. This strategy provides a simple and effective method for the preparation of high-performance, low-cost, and green energy storage materials.
研究领域:
材料科学
·
能源存储技术
·
生物质化学
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产品关联
DOI
高影响因子
Emerging Microbes & Infections
·
2018
·
IF 6.032
Jin-xin Zheng,Zhi-wei Lin,Xiang Sun,Wei-hong Lin,Zhong Chen,Yang Wu,Guo-bin Qi,Qi-wen Deng,Di Qu,Zhi-jian Yu
This study investigated the characteristics and mechanisms of eravacycline resistance and heteroresistance in clinical Klebsiella pneumoniae isolates. A total of 393 clinical K. pneumoniae isolates were collected and subjected to eravacycline and tigecycline MIC determinations using the agar dilution method. Eravacycline heteroresistance was assessed by a population analysis profile (PAP). The expression levels of efflux pumps and their regulators were determined by quantitative reverse-transcription PCR (qRT-PCR). This study identified 67 eravacycline-nonsusceptible isolates; among the extended-spectrum β-lactamase (ESBL)-positive isolates, eravacycline-nonsusceptible isolates were detected more frequently than tigecycline-nonsusceptible isolates (21.7% vs. 9.4%, p = 0.001). The study sample was observed to include 20 K. pneumoniae isolates with eravacycline heteroresistance. Compared to the reference strain, oqxA or oqxB overexpression was observed in nine eravacycline-nonsusceptible isolates (range, 35.64–309.02-fold) and 13 eravacycline-heteroresistant isolates (8.42–296.34-fold). The overexpression of macA or macB was detected in 12 eravacycline-heteroresistant isolates (3.23–28.35-fold). Overexpression of the efflux pump regulator gene ramA was observed in 11 eravacycline-nonsusceptible isolates (3.33–94.05-fold) and 18 eravacycline-heteroresistant isolates (3.89–571.70-fold). The eravacycline MICs were increased by one–fourfold by overexpression of oqxAB or macAB in three eravacycline-sensitive isolates. In conclusion, the overexpression of OqxAB and MacAB efflux pumps and the transcriptional regulator RamA were suggested to be involved in K. pneumoniae eravacycline resistance and heteroresistance.
研究领域:
微生物学
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医学
·
药理学
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产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Haiyan Zhang,Zhiguang Xu,Tao Zhang,Yan Zhao
Superhydrophobicity and hygroscopicity are two properties that are theoretically exclusive to each other. The fabrication of functional fabrics with these two properties remains very challenging. In this work, it is demonstrated that a non-sticky superhydrophobic and hygroscopic fabric coating can be prepared via the photo polymerization of hexadecyl acrylate and methacrylic acid. On coating surface , the phase-separation-induced chemical heterogeneity has a unique feature of possessing elevated continuous hydrophobic domain and depressed hydrophilic domain, as evidenced by atomic force microscopy measurement. The elevation of hydrophobic domain (i.e., depression of hydrophilic domain) allows the hydrophilic domain to make negligible contribution to the surface wettability to water drop, but can absorb water molecules, thus inducing the unique superhydrophobic but hygroscopic property. The coating has a very low total surface energy of 22.61 mN m −1 , with its polar part (0.01 mN m −1 ) being negligible, thereby showing a high static water contact angle of ~112° on flat glass slide. The coated polyester fabric shows a non-sticky superhydrophobicity with a static water contact angle of ~151° and a water shedding angle of ~10°, as well as good hygroscopic and anti-static properties. We anticipate that this novel coating and the reported strategy of generating the particular chemical heterogeneity may lead to the development of advanced special wettability coatings for various applications.
研究领域:
材料科学
·
表面化学
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产品关联
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Yaxin Qiu,Dheeman-Roy Munna,Fang Wang,Juqun Xi,Zhifeng Wang,Defeng Wu
For shape-memory polymers (SMPs), introducing material heterogeneity is vital to tailor shape-shifting pathways. However, it is hard to reprogram the heterogeneity for both covalent networks and dynamic covalent networks after these networks are encoded. Here, photoactive coumarin derivative end-capped dangling chains were used to participate in building photoreversible polycaprolactone/poly(malic acid) networks, endowing the networks with reprogrammable heterogeneity and a capability of room-temperature storage of entropic energy. The alternations of network topology with 365/254 nm UV irradiation and strain-induced crystallization behavior of as-prepared bio-based elastomers were studied, aiming at quantitatively guiding the spatiotemporal release of entropic energy to regulate asynchronous deformations. This work provides applicable methods for simplifying shaping manipulation or for diversifying shape-shifting pathways of SMPs.
研究领域:
材料科学
·
高分子化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Biomaterials Advances
·
2025
·
IF 6
Yingjun Yang,Kai Wang,Xin Li,Shukai Ding,Miao Zhang,Siyuan Huang
Currently, in vitro fabrication of intra-tissue heterogeneity remains a critical challenge in development of adult stem cell based tissue engineering. Interestingly, as a typical structure in symmetry-breaking phase transitions, topological defects are extensively presented in biological substances. These topological defects are commonly observed within cell monolayer in vitro and demonstrated to be effective in induction of intra-tissue heterogeneity by regulating cell migration. Nevertheless, their impacts on the behavior of mesenchymal stem cells (MSCs) remain elusive. In this study, micro-grooved substrates were utilized to explore the role of topological defects in regulation of MSCs' self-organization and osteogenic differentiation. The results indicated that topological defects could induce the central aggregates of MSCs at central region of +1 and +1/2 topological defects by modulating centripetal migration. On the contrast, negatively charged topological were able to induce centrifugal migration and further inducing heterogeneous distribution of MSCs. Subsequently, these heterogeneously distributed MSCs were capable of inducing intra-tissue heterogeneity in terms of proliferation, stemness maintenance and osteogenic differentiation via regulatory morphogenesis.
研究领域:
细胞生物学
·
组织工程学
·
再生医学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Yihui Lv,Qi Shi,Xiaocao Yan,Yudong Cai,Yunxuan Weng,Hainan Gao
The responsive secreting function of artificial materials plays an important role in wettability, self-regulation, self-lubrication, antifouling, and controlled loading and release. Drawing inspiration from the secretory tissues in plant bodies, here we present a facile strategy to prepare a stimuli-responsive organohydrogel with water-driven and thermally-driven oil-release functions, and the responsive wettability is achieved. In essence, the stimuli-responsive secretory function is inextricably linked to the infiltration and exfiltration behavior of different dispersion media between heterogeneous networks. The responsive deswelling of the dispersion medium can be induced by certain environmental factors, including changing the dispersion medium or environmental temperature, which further enables unique on-demand water-driven and thermally-driven oil-release properties. It is anticipated that such smart, self-secreting organohydrogel materials, featured with controllable liquid loading and releasing properties, have great potential in a variety of fields, such as drug delivery systems, self-lubrication and antifouling surfaces, and controlled embedding and release of bioactive molecules.
研究领域:
材料科学
·
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）