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1.
J Cell Physiol ; 235(1): 221-231, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31187497

RESUMO

The motility of mesenchymal stem cells (MSCs) is highly related to their homing in vivo, a critical issue in regenerative medicine. Our previous study indicated copper (Cu) might promote the recruitment of endogenous MSCs in canine esophagus defect model. In this study, we investigated the effect of Cu on the motility of bone marrow mesenchymal stem cells (BMSCs) and the underlying mechanism in vitro. Cu supplementation could enhance the motility of BMSCs, and upregulate the expression of hypoxia-inducible factor 1α (Hif1α) at the protein level, and upregulate the expression of rho family GTPase 3 (Rnd3) at messenger RNA and protein level. When Hif1α was silenced by small interfering RNA (siRNA), Cu-induced Rnd3 upregulation was blocked. When Rnd3 was silenced by siRNA, the motility of BMSCs was decreased with or without Cu supplementation, and Cu-induced cytoskeleton remodeling was neutralized. Furthermore, overexpression of Rnd3 also increased the motility of BMSCs and induced cytoskeleton remodeling. Overall, our results demonstrated that Cu enhanced BMSCs migration through, at least in part, cytoskeleton remodeling via Hif1α-dependent upregulation of Rnd3. This study provided an insight into the mechanism of the effect of Cu on the motility of BMSCs, and a theoretical foundation of applying Cu to improve the recruitment of BMSCs in tissue engineering and cytotherapy.

2.
J Hazard Mater ; : 121706, 2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31796358

RESUMO

Cadmium (Cd) is an environmental contaminant found in soil, water, and food, and can cause oxidative stress and male reproductive damage. During puberty, the male reproductive system is very vulnerable to interference, however, the dysregulation of Cd on spermatogenesis in this period is ambiguous. The anthocyanin cyanidin-3-O-glucoside (C3G) is phytochemical rich in plants and fruits and has been shown to have remarkable anti-oxidant activity, making it an ideal nutrient for nutritional intervention. By modeling Cd-induced damage in male pubertal mice and feeding with C3G, we demonstrated that the C3G could rescue the amount and activity of sperm predominantly. Furthermore, C3G showed partial resistance to Cd-induced histone modification during spermiogenesis and prevented oxidative damage of the DNA in the sperm nucleus. Additionally, C3G mitigated the oxidative stress of testis to achieve the level coinciding with the control group. Meanwhile, Cd-induced mitochondrial apoptosis of sperm cells was reduced significantly via the MAPK signaling pathway in the presence of C3G. Collectively, our findings can offer a potential intervention for combating Cd-induced reproductive damage during puberty by taking anthocyanin as a dietary supplement.

3.
Nat Commun ; 10(1): 5469, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784537

RESUMO

Biomolecular cryptography exploiting specific biomolecular interactions for data encryption represents a unique approach for information security. However, constructing protocols based on biomolecular reactions to guarantee confidentiality, integrity and availability (CIA) of information remains a challenge. Here we develop DNA origami cryptography (DOC) that exploits folding of a M13 viral scaffold into nanometer-scale self-assembled braille-like patterns for secure communication, which can create a key with a size of over 700 bits. The intrinsic nanoscale addressability of DNA origami additionally allows for protein binding-based steganography, which further protects message confidentiality in DOC. The integrity of a transmitted message can be ensured by establishing specific linkages between several DNA origamis carrying parts of the message. The versatility of DOC is further demonstrated by transmitting various data formats including text, musical notes and images, supporting its great potential for meeting the rapidly increasing CIA demands of next-generation cryptography.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31786930

RESUMO

Liquid crystal elastomer (LCE) as a kind of stimuli-responsive materials, which can be fabricated to present the three-dimensional (3D) change in shape, shows wide range of applications. Herein, we propose a simple and robust way to prepare 3D shape-change actuator based on gradient crosslinking of the vertically-aligned monodomain of liquid crystals (LCs). First, gold nanoparticles grafted by liquid crystalline polymers (LCPs) are used to induce the homeotropic orientation of the LC monomer and crosslinkers. Then, photopolymerization under UV irradiation is carried out, which can result in the LCE film with crosslink gradient. Different from the typical LCEs with homogenous alignment that usually show the shape change of extension/contraction, the obtained vertically-aligned LCE film exhibits excellent bendability under thermal stimulus. Nanoindentation experiment demonstrates that the deformation of LCE films comes from the difference in Young's modulus on two sides of the thin film. Simply scissoring the thin film can prepare the samples with different bending angles under the fixed length. Moreover, using photo mask to pattern the film during photopolymerization can realize the complex 3D deformation, such as bend, fold, and buckling. Further, the patterned LCE film doped with multiwalled carbon nanotubes modified by LCPs (CNT-PDB) can act as a light-fueled micro-walker with fast crawl behavior.

5.
J Environ Sci (China) ; 86: 187-194, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31787183

RESUMO

Enzymatic electrolysis cell (EEC) has advantages over microbial electrolysis cell (MEC) due to the needless of microbe inoculation and high-efficiency of enzymatic reaction. In this study, an EEC was first applied to achieve the effective degradation of halogenated organic pollutants and dichloromethane (CH2Cl2) was utilized as a model pollutant. The results indicate that the degradation efficiency of CH2Cl2 after 2 hr reaction in the EEC was almost 100%, which was significantly higher than that with enzyme (51.1%) or current (19.0%). The current induced the continuous regeneration of reduced glutathione (GSH), thus CH2Cl2 was degraded under the catalysis of GSH-dependent dehalogenase through stepwise dechlorination, and successively formed monochloromethane (CH3Cl) and methane (CH4). The kinetic result shows that with a current of 15 mA, the maximum specific degradation rate of CH2Cl2 (3.77 × 10-3hr-1) was increased by 5.7 times. The optimum condition for CH2Cl2 dechlorination was also obtained with pH, current and temperature of 7.0, 15 mA and 35°C, respectively. Importantly, this study helps to understand the behavior of enzymes and the fate of halogenated organic pollutants with EEC, providing a possible treatment technology for halogenated organic pollutants.

6.
Chem Commun (Camb) ; 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31789329

RESUMO

The terahertz dynamics of water nanodroplets confined in phospholipid reverse micelles have been developed as a probe to explore the interactions of metal ions with lipid membrane interfaces. The terahertz absorption coefficients of reverse micelles vary greatly with different Cu2+ concentrations and with different headgroups. The results proved that the metal ion effects on water dynamics near a membrane surface can be detected via terahertz spectroscopy, thus providing a novel tool for investigating ion-lipid interactions.

7.
Langmuir ; 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804082

RESUMO

Nanoparticle-decorated Polymer-coated Sub-microbubbles (NP-P-coated SMBs) as proved have shown promising application prospects in ultrasound imaging, magnetic resonance imaging and drug delivery, etc. However, the quantitative evaluation of the stability and mechanical properties of single NP-P-coated SMB are absent. Here, we firstly reported the stiffness and Young modulus of single NP-P-coated SMB obtained by Peakforce mode of atomic force microscopy. Such NP-P-coated SMBs could maintain perfect spherical shapes and has a thinner shell thickness (about 10 nm) by characterization of transmission electron microscope. The Young modulus of NP-P-coated SMBs is about 4.6 ± 1.2 GPa and their stiffness is about 15.0 ± 3.1 N/m. Both modulus and stiffness are obtained from the linear region in the force-deformation curve and are nearly independent on their sizes. Those results should be very useful to evaluate their stability, which plays a key role in maintaining the shell drug loading and acoustic capabilities.

8.
Nat Commun ; 10(1): 5552, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804474

RESUMO

Adding small nanoparticles (NPs) into polymer melt can lead to a non-Einstein-like decrease in viscosity. However, the underlying mechanism remains a long-standing unsolved puzzle. Here, for an all-polymer nanocomposite formed by linear polystyrene (PS) chains and PS single-chain nanoparticles (SCNPs), we perform large-scale molecular dynamics simulations and experimental rheology measurements. We show that with a fixed (small) loading of the SCNP, viscosity reduction (VR) effect can be largely amplified with an increase in matrix chain length [Formula: see text], and that the system with longer polymer chains will have a larger VR. We demonstrate that such [Formula: see text]-dependent VR can be attributed to the friction reduction experienced by polymer segment blobs which have similar size and interact directly with these SCNPs. A theoretical model is proposed based on the tube model. We demonstrate that it can well describe the friction reduction experienced by melt polymers and the VR effect in these composite systems.

9.
J Cell Mol Med ; 2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31736204

RESUMO

Patients with diabetes have an increased risk of vascular complications. Suv39h1, a histone methyltransferase, plays a protective role against myocardial injury in diabetes. Herein, we intend to explore whether Suv39h1 could affect neointimal formation after vascular injury in diabetic rats and reveal the underlying mechanism. In this study, we generated adenovirus expressing Suv39h1 as well as lentivirus expressing Suv39h1-targeting shRNA and evaluated the significance of Suv39h1 in vascular smooth muscle cells (VSMCs) under diabetic conditions. In vitro, we examined proliferative and migratory behaviours as well as the underlying signalling mechanisms in VSMCs in response to high glucose treatment. In vivo, we induced diabetes in SD rats with streptozocin and established the common carotid artery balloon injury model. Suv39h1 was found to be both necessary and sufficient to promote VSMC proliferation and migration under high glucose conditions. We observed corresponding changes in intracellular signalling molecules including complement C3 and phosphor-ERK1/2. However, either up-regulating or down-regulating Suv39h1, phosphor-p38 level was not significantly affected. Consistently, Suv39h1 overexpression led to accelerated neointima formation, while knocking down Suv39h1 reduced it following carotid artery injury in diabetic rats. Using microarray analyses, we showed that altering the Suv39h1 level in vivo dramatically altered the expression of myriad genes mediating different biological processes and molecular function. This study reveals the novel role of Suv39h1 in VSMCs of diabetes and suggests its potential role as a therapeutic target in diabetic vascular injury.

10.
J Am Chem Soc ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31763827

RESUMO

Despite the many attempts to build ultrathin 2D-2D heterojunctions via wet chemical methods, the resulting composite materials reported to date suffer from poor interfacial bonding and/or complexity of the synthetic protocols. Encouraged by the structural compatibility of Bi2WO6 and Bi2O2S, both of which are 2D semiconductors sharing a rather similar structural unit of [Bi2O2]2+ slice in their crystal structures, we have successfully fabricated an ultrathin nanosheet with a tightly bonded 2D-2D heterojunction between the two components by facilely joining the [Bi2O2]2+ and [S]2- slices using a simple two-step hydrothermal method. Such a Bi2WO6-Bi2O2S 2D-2D heterojunction has a five-alternating-layer (Bi2O2S-Bi2WO6-Bi2O2S-Bi2WO6-Bi2O2S) sandwich structure and a thickness down to ca. 5 nm, and was obtained by simply growing Bi2O2S layer in-situ on the surface of monolayer Bi2WO6 nanosheets. The judicious combination of Bi2WO6 and Bi2O2S through a 2D-2D heterojunction not only extended light absorption in the visible range but also significantly enhanced photo(electro)chemical water splitting efficiencies compared to the bare Bi2WO6 nanosheets alone due to the close-bonding promoted interfacial charge separation. Our findings provide a viable methodology to build a host of nanomaterials with closely bonded 2D nanosheets, which can be used as photocatalysts and electrocatalysts, among others.

11.
Phys Chem Chem Phys ; 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31746854

RESUMO

A first-principles approach is employed to study the influences of the metal species Al, Zr, Mo and Tc on the mechanical properties of U3Si2. When the Al, Zr, Mo and Tc atoms diffuse into the vacancy sites, they dissolve into the lattice, as confirmed by the solution energies. It is found that the compounds of U3Si2 with low amounts of Al, Zr, Mo, and Tc in the Si vacancies or Al, Zr, and Mo in the U vacancies can behave in the manner of ductility. However, in the cases where Al, Zr, Mo and Tc occupy the interstitial sites, all the compounds are demonstrated to be brittle. Furthermore, the stress-strain relationship for the U3Si1.9375Mo0.0625 system was calculated, which illustrates the enhanced ductility. The current results indicate that the substitution of Si by carefully selected metal atoms can enhance the performance of U3Si2.

12.
J Phys Chem Lett ; 10(23): 7362-7367, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31711289

RESUMO

Two-dimensional coherent photocurrent spectroscopies directly probe the electronic states and processes that are relevant to the performance of a photovoltaic device. In this Letter, we apply two-pulse nonlinear photocurrent spectroscopy to a photovoltaic device based on layered perovskite quantum wells. The method effectively decomposes the photovoltaic response into contributions from separate quantum wells and excited-state species (i.e., either single excitons or biexcitons). Our experiments show that the efficiency of photocurrent generation increases with the size of the quantum well. Overall, the results suggest that energy funneling processes in layered perovskites, which are most prominent in transient absorption spectroscopies, are largely irrelevant to the function of a photovoltaic cell.

13.
Diabetes Metab Res Rev ; : e3245, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31758628

RESUMO

OBJECTIVE: Fetal sex has recently been considered to be related to maternal glucose homeostasis and perinatal outcomes during pregnancy. Here, we investigated the effects of fetal sex on the perinatal outcomes of pregnancies with normal glucose tolerance (NGT) and gestational diabetes mellitus (GDM). METHODS: This was a retrospective cohort study of 1292 women with NGT and 1155 women with GDM. Pregnant women were divided into four groups according to the maternal glucose level and fetal sex. Logistic regression was used to evaluate the risks for adverse perinatal outcomes among NGT-males, NGT-females, GDM-males and GDM-females. RESULTS: NGT-males had higher risks for macrosomia and large for gestational age (LGA) than NGT-females with an odds ratio (OR) of 1.9 (95% CI 1.2-2.9). Additionally, GDM-males had higher risks for neonatal infection (OR, 3.0; 95% CI, 1.3-6.9), acute respiratory disorders (OR, 3.9; 95% CI, 1.1-13.7) and abnormal neonatal central nervous system development (OR, 3.1; 95% CI, 1.1-8.4) than GDM-females. Furthermore, there was a significantly higher risk for newborn infection (OR, 8.5; 95% CI, 1.1-66.8) in the GDM-male group than in the GDM-female group with a glycosylated hemoglobin A1c (HbA1c) level ≥5.5% in the late trimester of pregnancy, which was not observed with an HbA1c level of <5.5%. CONCLUSIONS: Male fetuses have worse perinatal outcomes than female fetuses, and the difference is more pronounced in GDM pregnancies. More postpartum care is needed for male fetuses, especially in GDM pregnancies with substandard glycemic control.

14.
J Phys Chem A ; 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730355

RESUMO

Two-dimensional (2D) hybrid perovskites are generating broad scientific interest because of their potential for use in photovoltaics and microcavity lasers. It has recently been demonstrated that mixtures of quantum wells with different thicknesses can be assembled in films with heterogeneous quantum well distributions. Large (small) quantum wells are concentrated at the air-side (substrate-side) of the films, thereby promoting directional energy and/or electron transfer. However, profiles of the quantum well concentrations have not been directly measured throughout the full thicknesses of the films. Similarly, the lateral motions of the excitations in these systems are not well-characterized. In this work, we perform focused ion beam milling tests to establish quantum well concentrations as a function of depth in layered 2D perovskite films. In addition, transient absorption microscopy is used to investigate carrier diffusion and two-body recombination processes. Comparisons of the layered films with phase-pure single crystals reveal that diffusion is suppressed by grain boundaries in the films, which in turn promotes two-body recombination. Similar behaviors were previously observed in bulk perovskite films and single crystals. These studies suggest that the morphology of the film, rather than the identity of the material, is the primary factor that governs the two-body recombination dynamics. Enhancement of two-body recombination processes is desirable for applications such as microcavity lasers.

15.
J Hazard Mater ; : 121578, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31732343

RESUMO

During the bloom seasons, the dissolved inorganic nitrogen declines, which results in the occurrence of nitrogen limitation. It is unclear where the nitrogen goes. Our enclosure experiments and batch tests suggested that Microcystis blooms could significantly reduce the nitrogen in water bodies and the key mechanisms for the nitrogen reduction in different layers were different. The assimilation was the main pathway for nitrogen reduction in the surface layer, while denitrification played an important role both at the sediment-water interface and in the overlying water. Stable nitrogen isotope experiments showed that the nitrate reduction efficiency at sediment-water interface was enhanced by Microcystis, reaching to 76.5∼84.7 %. Dissimilation accounted for 63.8∼67.3 % of the nitrate reduction, and the denitrification rate was 7.4∼8.5 times of DNRA rate. In the water column, the Microcystis bloom facilitated the formation of dark/anoxic condition, which favored the denitrification. The Microcystis aggregates collected from the field showed a great potential in removing nitrogen, and the TN in the overly water was reduced by 3.76∼6.03 mg L-1 within two days. This study provided field evidences and deeper insights into the relationship between Microcystis blooms and nitrogen reduction in the whole water column and gave more details about the enhancing effects of Microcystis on nitrogen reduction.

16.
Circ Arrhythm Electrophysiol ; 12(11): e007382, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31726860

RESUMO

BACKGROUND: STIM1 (stromal interaction molecule 1) is a calcium (Ca2+) sensor that regulates cardiac hypertrophy by triggering store-operated Ca2+ entry. Because STIM1 binding to phospholamban increases sarcoplasmic reticulum Ca2+ load independent of store-operated Ca2+ entry, we hypothesized that it controls electrophysiological function and arrhythmias in the adult heart. METHODS: Inducible myocyte-restricted STIM1-KD (STIM1 knockdown) was achieved in adult mice using an αMHC (α-myosin heavy chain)-MerCreMer system. Mechanical and electrophysiological properties were examined using echocardiography in vivo and optical action potential (AP) mapping ex vivo in tamoxifen-induced STIM1flox/flox-Cretg/- (STIM1-KD) and littermate controls for STIM1flox/flox (referred to as STIM1-Ctl) and for Cretg/- without STIM deletion (referred to as Cre-Ctl). RESULTS: STIM1-KD mice (N=23) exhibited poor survival compared with STIM1-Ctl (N=22) and Cre-Ctl (N=11) with >50% mortality after only 8-days of cardiomyocyte-restricted STIM1-KD. STIM1-KD but not STIM1-Ctl or Cre-Ctl hearts exhibited a proclivity for arrhythmic behavior, ranging from frequent ectopy to pacing-induced ventricular tachycardia/ventricular fibrillation (VT/VF). Examination of the electrophysiological substrate revealed decreased conduction velocity and increased AP duration (APD) heterogeneity in STIM1-KD. These features, however, were comparable in VT/VF(+) and VT/VF(-) hearts. We also uncovered a marked increase in the magnitude of APD alternans during rapid pacing, and the emergence of a spatially discordant alternans profile in STIM1-KD hearts. Unlike conduction velocity slowing and APD heterogeneity, the magnitude of APD alternans was greater (by 80%, P<0.05) in VT/VF(+) versus VT/VF(-) STIM1-KD hearts. Detailed phase mapping during the initial beats of VT/VF identified one or more rotors that were localized along the nodal line separating out-of-phase alternans regions. CONCLUSIONS: In an adult murine model with inducible and myocyte-specific STIM1 depletion, we demonstrate for the first time the regulation of spatially discordant alternans by STIM1. Early mortality in STIM1-KD mice is likely related to enhanced susceptibility to VT/VF secondary to discordant APD alternans.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31704169

RESUMO

OBJECTIVES: To monitor the serological typing of Haemophilus influenzae(Hi) in the lower respiratory tract infection in western Sichuan, China, the changes in beta-lactam resistance of the strains and the mechanism of beta-lactam resistance in these isolates over the past decade. METHODS: 54 strains of Nontypeable Haemophilus influenzae (NTHi) isolated from 2003 to 2004 and 220 strains of NTHi isolated from 2013 to 2014 were selected randomly. Hi strains were characterized by serological typing, and by PCR analysis of the p6, fucK and cap gene. The MIC values for ampicillin (AMP), Amoxicillin-clavulanic (AMC) acid and cefuroxime (CXM) were determined by broth microdilution susceptibility test. The TEM-1, ROB-1 and ftsI genes of the strain were sequenced; We compared the data obtained over a decade. The mechanisms of beta-lactam resistance and the effect of amino acid substitution of the ftsI gene on the MIC values of AMP, AMC and CXM were analyzed, respectively. RESULTS: 1. The MIC values of AMP, AMC and CXM of the NTHi strains isolated during 2013˜2014 were significantly higher than those of the strains collected during 2003˜2004 by rank sum test, p < 0.05. 2. BLA positive strains were 51.46% (141/274); gene sequencing showed that all 141 beta-lactamase positive strains were TEM-1 type. 3. There were 32 amino acid substitutions of the ftsI gene sequence and three of them had two amino acid substitutions in the NTHi isolated from 2013 to 2014. However, NTHi strains isolated from 2003 to 2004 had only the 9 amino acids substitutions (D350 N, M377I, A437S, G490E, A502 V,V511A, R517H and N526 K). 4. The results of rank sum test showed that only a few amino acids had no significant difference in the MIC values between the three beta-lactams. Ordered multiple classification logistic regression analysis showed that different amino acid replacement patterns of the ftsI gene had different effects on the MIC values of AMP, AMC and CXM, respectively. The main factors affecting the MIC value of AMP were in turn R517H (OR = 7.128), L389 F (OR = 6.999), N526 K (OR = 4.660) and D350 N (OR = 0.450); The main factor influencing the MIC value of AMC was an N526 K mutation (OR = 9.349);The main factors affecting the MIC value of CXM were the mutations S357 N (OR = 37.453) and N526 K (OR = 14.816). 5. Compared with the strains isolated from 2003 to 2004, the gBLNAR and gBLPAR strains isolated from 2013 to 2014 increased significantly from 12.96% (7/54), 9.26% (7/54) to 42.0% (84/220), 45.45% (100/220) respectively, p < 0.001. 6. Only 36.22% of the strains in the ftsI gene mutation fit the condition of group I ˜ III, and the group Ⅲ-like strain was 23.98% (47/196). In addition to M377I, S385 T, L389 F and N526 K mutations, all 47 NTHi strains also had amino acid substitution for D350 N and S357I. In other group, 13 NTHi strains had the same ftsI gene mutation pattern and 24 amino acid substitutions. CONCLUSIONS: Our results confirmed that Hi isolated from the lower respiratory tract of Western Sichuan in China from 2013 to 2014 were NTHi strains. Compared with ten years earler, beta-lactamase producing strains and beta-lactam resistant strains increased rapidly. The amino acid substitution of the ftsI gene was more complex and diversified. So far, although some progress has been made in the study of antibiotical resistance mechanism of NTHi strains, how to control the growth of NTHi resistant strains is still a challenge in China.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31692202

RESUMO

Introducing specific textures to titanium alloy implant surface is helpful to modify the surface properties of materials. In this article, biomedical TC4 (Ti-6Al-4V) alloy was textured by a 10-ps infrared laser. Laser parameters that directly affected the detailed dimension of textures and its characteristics were optimized within laser power, defocusing amount, and scanning parameters via response surface methodology. These textures consisted of groove array about 30-90 µm in depth and 100 µm in width were prepared and their surface property (including surface morphology, element composition, wetting behavior, and biocompatibility) was analyzed. Surface characteristic analysis indicated that picosecond laser texturing improved surface properties and biocompatibility mainly by altering the microstructure and morphology of materials. In addition, laser textured groove array promoted contact area and hydrophobicity of material surface. Cell culture experiments and animal studies showed that titanium alloy implants with 30- and 60-µm-deep groove arrays on the surface-enhanced cell proliferation and adhesion. Meanwhile, compared to the polished samples, these groove arrays promoted the growth of new blood vessels and enhanced the combination of blood vessel and implants in vivo. That is, the deeper groove array was, and the better vascularizing effect the blood vessel exhibited.

20.
ACS Appl Mater Interfaces ; 11(47): 44751-44757, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31689074

RESUMO

By adjusting the stretch state of a triethylenetetramine (TETA) chain in an amine-functionalized porous organic polymer (POP), two adsorbents were designed to study the rational microenvironment for heavy metal ion removal. The quantum calculation elucidated that the hooped amino chains in FC-POP-CH2TETA-H exhibited stronger interactions with Pb(II) than the extended one in FC-POP-CH2TETA-E, not only through metal-ligand chelation but also metal coordination. The high binding energy of -2624 kJ mol-1 as well as the constructed microenvironment by the hooped amino chains ensured an extremely high Pb(II) capacity of 1134 mg g-1 on FC-POP-CH2TETA-H. Meanwhile, no more than 5 min to approach adsorption equilibrium revealed its ultrafast adsorption rate. It also showed excellent broad removal capability for multiple metal ions and nonsensitivity to pH. Therefore, by controlling the microenvironmental structures with suitable porosity, functional group stretching states, and coordination modes, the removal efficiency of heavy metal ions would be significantly enhanced, which further provided a promising strategy for designing a rational microenvironment to improve the task-specific separation properties.

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