Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
Neuro Oncol ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023130

RESUMO

BACKGROUND: Pediatric low-grade glioma incidence has been rising in the U.S., mirroring the rising rates of pediatric and maternal obesity. Recently, children of obese mothers were demonstrated to develop brain tumors at higher rates. Importantly, obesity in the U.S. is largely driven by diet, given the prevalence of high fat and high sugar (HFHS) food choices. Since high-fat diet exposure can increase embryonic neuroglial progenitor cell (NPC) proliferation, the potential cells of origin for low-grade glioma, we hypothesized that in utero exposure to an obesogenic diet would modify pediatric brain penetrance and latency by affecting the tumor cell of origin. METHODS: We employed several murine models of the Neurofibromatosis type 1 (NF1) pediatric brain tumor predisposition syndrome, in which optic pathway gliomas (Nf1-OPGs) arise from NPCs in the embryonic third ventricular zone (TVZ). We exposed dams and offspring to an obesogenic HFHS diet or control chow and analysed fetal neurodevelopment at E19.5 and tumor formation at 6w-3mo. RESULTS: Progeny from HFHS diet-exposed dams demonstrated increased TVZ NPC proliferation and glial differentiation. Dietary switch cohorts confirmed that these effects were dependent upon maternal diet, rather than maternal weight. Obesogenic diet (Ob) similarly accelerated glioma formation in a high-penetrance Nf1-OPG strain and increased glioma penetrance in two low-penetrance Nf1-OPG strains. In contrast, Ob exposure in the postnatal period alone did not recapitulate these effects. CONCLUSIONS: These findings establish maternal obesogenic diet as a risk factor for murine Nf1-OPG formation, acting in part through in utero effects on the tumor cell of origin.

2.
iScience ; 26(12): 108455, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38077126

RESUMO

Wood, with its inherent hierarchical structure, presents opportunities for creating eco-friendly and cost-effective alternatives to petroleum-based plastics. We introduced a top-down and polymer-free method for engineering natural balsa wood into transparent wood film, demonstrating its potential use in food packaging windows. The wood was delignified and then proceeded with 2,2,6,6-tetramethyl-1-piperidinyloxy oxidation to soften the wood structure and introduce carboxyl groups. A robust and transparent wood film was produced by drying the wood under ambient condition without the need for additional polymers or mechanical force. Curcumin was also integrated into the wood using vacuum impregnation. The functionalized wood film with curcumin (WFC) exhibited a distinguishable redness shift in alkaline conditions. We then applied the WFC as an intelligent food packaging window to sense the freshness of shrimp based on the pH-responsive color change. This study provides a simple and scalable approach for developing sustainable and smart food packaging using wood.

3.
ACS Nano ; 17(19): 19087-19097, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37726178

RESUMO

Uneven zinc (Zn) deposition typically leads to uncontrollable dendrite growth, which renders an unsatisfactory cycling stability and Coulombic efficiency (CE) of aqueous zinc ion batteries (ZIBs), restricting their practical application. In this work, a lightweight and flexible three-dimensional (3D) carbon nanofiber architecture with uniform Zn seeds (CNF-Zn) is prepared from bacterial cellulose (BC), a kind of biomass with low cost, environmental friendliness, and abundance, as a host for highly reversible Zn plating/stripping and construction of high-performance aqueous ZIBs. The as-prepared 3D CNF-Zn with a porous interconnected network significantly decreases the local current density, and the functional Zn seeds provide uniform nuclei to guide the uniform Zn deposition. Benefiting from the synergistic effect of Zn seeds and the 3D porous framework in the flexible CNF-Zn host, the electrochemical performance of the as-constructed ZIBs is significantly improved. This flexible 3D CNF-Zn host delivers a high and stable CE of 99.5% over 450 cycles, ensuring outstanding rate performance and a long cycle life of over 500 cycles at 4 A g-1 in the CNF-Zn@Zn//NaV3O8·1.5H2O full battery. More importantly, owing to the flexibility of the 3D CNF-Zn host, the as-assembled pouch cell shows outstanding mechanical flexibility and excellent energy storage performance. This strategy of producing readily accessible carbon from biomass can be employed to develop advanced functional nanomaterials for next-generation flexible energy storage devices.

4.
Adv Sci (Weinh) ; 10(32): e2303830, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37747263

RESUMO

The sluggish kinetics of sulfur conversions have long been hindering the implementation of fast and efficient sulfur electrochemistry in lithium-sulfur (Li-S) batteries. In this regard, herein the unique chromium boride (CrB) is developed via a well-confined mild-temperature thermal reaction to serve as an advanced sulfur electrocatalyst. Its interstitial-alloy nature features excellent conductivity, while the nano-lamination architecture affords abundant active sites for host-guest interactions. More importantly, the CrB nanocatalyst demonstrates a dual sulphophilicity with simultaneous Cr─S and B─S bondage for establishing strong interactions with the intermediate polysulfides. As a result, significant stabilization and promotion of sulfur redox behavior can be achieved, enabling an excellent Li-S cell cyclability with a minimum capacity fading rate of 0.0176% per cycle over 2000 cycles and a favorable rate capability up to 7 C. Additionally, a high areal capacity of 5.2 mAh cm-2 , and decent cycling and rate performances are still attainable under high sulfur loading and low electrolyte dosage. This work offers a facile approach and instructive insights into metal boride sulfur electrocatalyst, holding a good promise for pursuing high-efficiency sulfur electrochemistry and high-performance Li-S batteries.

5.
Molecules ; 28(8)2023 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-37110736

RESUMO

ß-lactoglobulin (ß-Lg) is a protein found in milk that can cause severe allergic reactions, including rash, vomiting, and diarrhea. Thus, it is crucial to develop a sensitive ß-Lg detection method to protect people who are susceptible to allergies. Here, we introduce a novel and highly sensitive fluorescent aptamer biosensor for detecting ß-Lg. First, a fluorescein-based dye (FAM)-labeled ß-lactoglobulin aptamer (ß-Lg aptamer) is adsorbed on the surface of tungsten disulfide (WS2) nanosheets via van der Waals forces, resulting in fluorescence quenching. When ß-Lg is present, the ß-Lg aptamer selectively binds to ß-Lg, causing a conformational change in the ß-Lg aptamer and releasing it from the surface of WS2 nanosheets, which restores the fluorescence signal. Simultaneously, DNase I in the system cleaves the aptamer bound to the target, producing a short oligonucleotide fragment and releasing ß-Lg. The released ß-Lg then binds to another ß-Lg aptamer adsorbed on WS2, initiating the next round of cleavage, resulting in significant amplification of the fluorescence signal. This method has a linear detection range of 1-100 ng mL-1, and the limit of detection is 0.344 ng mL-1. Furthermore, this approach has been successfully used for detecting ß-Lg in milk samples with satisfactory results, providing new opportunities for food analysis and quality control.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Humanos , Lactoglobulinas , Desoxirribonuclease I , Técnicas Biossensoriais/métodos , Limite de Detecção
6.
Anal Methods ; 14(12): 1239-1245, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35258061

RESUMO

In this study, we demonstrate a colorimetric approach for the detection of hydrogen sulfide (H2S) in water samples with high sensitivity. Firstly, copper-metal-organic frameworks (Cu-MOFs) were synthesized by ultrasonic-assisted hydrothermal method, presenting a maximum absorption peak at 700 nm. It was found that Cu-MOFs could react with H2S to form a copper-sulfur complex along with a decrease of the absorption peak at 700 nm and a visible color change from blue to tan. Under the optimal reaction conditions, the absorption intensity at 700 nm was linear with H2S concentration in a range of 0.05-2 mM (R2 = 0.9928), providing a detection limit of 22 µM. Furthermore, the method was successfully applied to the detection of H2S in lake water samples with a recovery rate between 94.4% and 112.6%. In addition, a practical and portable device for on-site H2S detection was designed by using agarose hydrogels, and a simple colorimetric detection method based on a smartphone was developed. This analytical method showed good selectivity for H2S compared to other interfering substances, and the feasibility of the agarose hydrogel-based device was proved by the determination of H2S in real lake water samples.


Assuntos
Sulfeto de Hidrogênio , Estruturas Metalorgânicas , Colorimetria/métodos , Cobre , Sefarose , Smartphone , Água
7.
Cytotechnology ; 74(1): 65-75, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35185286

RESUMO

Mechanical strain regulated osteoclastic differentiation and angiogenesis are crucial for bone modeling and remodeling, and previous data indicate that high-magnitude strain within physiological load regulates osteoclastic differentiation. However, the underlying mechanisms are still not fully understood. In the present study, the RAW264.7 mouse monocyte/macrophage was used as an osteoclast precursor, and the bone marrow-derived macrophages (BMMs) were isolated and cultured in vitro. The above cells were subjected to macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) for the induction of osteoclast differentiation. Subsequently, the above cells were stretched by differential strain magnitudes to simulate the mechanical stimuli in the physiological conditions, and we found that low-magnitude strain (100 µÎµ) increased the expression levels of Acp5, Clcn7, MMP9 and Ctsk to promote osteoclastogenesis, while high-magnitude strain (3000 µÎµ) had opposite effects. In addition, we noticed that high-magnitude strain upregulated PTEN to inactivate the PI3K/Akt signaling pathway, and silencing of PTEN abrogated the suppressing effects of high-magnitude strain on osteoclastic differentiation. Next, we screened out that high-magnitude strain downregulated miR-21 to promote PTEN expressions in a competing endogenous RNA (ceRNA)-dependent manner. Finally, upregulation of miR-21 recovered osteoclastic differentiation in RAW264.7 and BMMs cells stimulated with high-magnitude strain. Collectively, our findings suggested that high-magnitude mechanical strain affected osteoclastic differentiation through modulating the miR-21/PTEN/PI3K/Akt signaling cascade, which provided potential strategies for the treatment of bone-related diseases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10616-021-00507-x.

8.
World J Clin Cases ; 10(3): 1131-1139, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35127929

RESUMO

BACKGROUND: Mycoplasma hominis (M. hominis), which causes central nervous system infections in adults, is very rare. It is also relatively difficult to culture mycoplasma and culturing requires special media, resulting in a high rate of clinical underdiagnosis. Therefore, clinicians often treat patients based on their own experience before obtaining pathogenic results and may ignore infections with atypical pathogens, thus delaying the diagnosis and treatment of patients and increasing the length of hospital stay and costs. CASE SUMMARY: A 44-year-old man presented to the hospital complaining of recurrent dizziness for 1 year, which had worsened in the last week. After admission, brain magnetic resonance imaging (MRI) revealed a 7.0 cm × 6.0 cm × 6.1 cm lesion at the skull base, which was irregular in shape and had a midline shift to the left. Based on imaging findings, meningioma was our primary consideration. After lesion resection, the patient had persistent fever and a diagnosis of suppurative meningitis based on cerebrospinal fluid (CSF) examination. The patient was treated with the highest level of antibiotics (meropenem and linezolid), but the response was ineffective. Finally, M. hominis was detected by next-generation metagenomic sequencing (mNGS) in the CSF. Therefore, we changed the antibiotics to moxifloxacin 0.4 g daily combined with doxycycline 0.1 g twice a day for 2 wk, and the patient had a normal temperature the next day. CONCLUSION: Mycoplasma meningitis after neurosurgery is rare. We can use mNGS to detect M. hominis in the CSF and then provide targeted treatment.

9.
J Mater Chem B ; 9(40): 8472-8479, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34550154

RESUMO

For the purpose of efficient targeted therapies, suppressing phagocytosis by a mononuclear phagocyte system (MPS), enhancing the "active" targeted delivery, and meeting clinical production criteria are extremely critical for engineering strategies of novel drug delivery systems. Herein, we used a chemically-induced membrane blebbing and extrusion combined method to induce triple-negative breast cancer (TNBC) cell apoptosis to secrete apoptotic body analogue (ABA) vesicles on a large scale for therapeutic drug delivery. After optimization, the ABAs have a desirable size, good biocompatibility, and long-term colloidal stability. Furthermore, ABAs present anti-phagocytosis ("don't eat me") and specific homologous targeting ("eat me") capacities because of their inheritance of membrane proteins such as CD47 and cellular adhesion molecules from parent cells. After loading with toxic protein saporin and anti-twist siRNA, ABAs can significantly inhibit the growth and lung metastasis of TNBC in an orthotopic metastasis model due to their reduced clearance of immune organs, long circulation time, and enhanced targeted accumulation at the tumor sites. These results suggest the great potential of ABAs for targeted drug delivery therapy, in particular efficient TNBC treatment.


Assuntos
Apoptose , Sistemas de Liberação de Medicamentos , Sistema Fagocitário Mononuclear/fisiologia , Neoplasias de Mama Triplo Negativas/terapia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Vesículas Extracelulares , Humanos , Camundongos , Camundongos Endogâmicos ICR , Camundongos Nus , Nanoestruturas , Fagocitose , Células RAW 264.7 , Distribuição Aleatória , Saporinas/química , Saporinas/farmacologia , Distribuição Tecidual , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Mol Ther Oncolytics ; 22: 232-244, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34514102

RESUMO

The difficulty of glioblastoma treatment makes it a good candidate for novel therapies, such as oncolytic viruses. Vesicular stomatitis virus expressing Lassa virus glycoprotein (Lassa-VSV) showed significant promise in animal models using established glioblastoma cell lines. These experiments were to determine the susceptibility of low-passage, patient-derived cell lines to Lassa-VSV oncolysis. Four patient-derived glioblastoma cell lines were infected with Lassa-VSV that expresses green fluorescent protein (GFP) and analyzed by fluorescence microscopy, flow cytometry, and cell viability assays. Cells were also analyzed as tumorspheres containing primarily glioma stem-like cells. Three low-passage, patient-derived cells were further analyzed with RNA sequencing (RNA-seq). Individual cell lines varied somewhat in their levels of viral gene expression and time course of Lassa-VSV-induced cell death, but each was susceptible to Lassa-VSV. Brain Tumor Center of Excellence (BTCOE) 4765 cells had the highest level of expression of interferon-stimulated genes but were most susceptible to Lassa-VSV-induced cell death, indicating that more susceptible cells do not necessarily have lower interferon pathway activation. Cells cultured as tumorspheres and infected with Lassa-VSV also showed variable susceptibility to Lassa-VSV, but BTCOE 4765 cells were least susceptible. Thus, patient-derived brain tumor cells show variable responses to Lassa-VSV infection, but each of the lines was susceptible to VSV oncolysis.

11.
Foods ; 10(6)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200160

RESUMO

The desire for foods with lower glycemic indices has led to the exploration of functional ingredients and novel food processing techniques. The glycemic index (GI) is a well-recognized tool to assess the capacity of foods to raise blood glucose levels. Among cereal crops, oats have shown the greatest promise for mitigating glycemic response. This review evaluated decades of research on the effects of oat components on the GI level of oat-based foods with specific emphasis on oat starch, ß-glucans, proteins, and phenolics. The effects of commonly used processing techniques in oats on GI level, including heating, cooling, and germination were also discussed. In addition, the GI of oat-based foods in various physical formats such as whole grain, flakes, and flour was systematically summarized. The aim of this review was to synthesize knowledge of the field and to provide a deeper understanding of how the chemical composition and processing of oats affect GI, thereby further benefiting the development of low-GI oat foods.

12.
Front Chem ; 9: 638557, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777901

RESUMO

In this work, titanium carbide (TiC) nanoparticles have been successfully synthesized at much lower temperatures of 500°C using cheaper starting materials, such as waste polytetrafluoroethylene (PTFE) (carbon source) and titanium and metallic sodium, than the traditional carbothermal reduction of TiO2 at 1,800°C. An XRD pattern proved the formation of face-centered cubic TiC, and TEM images showed the obtained TiC nanoparticles with an average size of approximately 50 nm. In addition, the separator coated with TiC nanoparticles as an active material of interlayer effectively mitigates the shuttling problem by taming the polysulfides in Li-S batteries compared with a traditional celgard separator. The assembled cell realizes good cycling stability with 501 mAh g-1 and a low capacity fading of 0.1% per cycle after 300 cycles at 1 C due to high utilization of the sulfur-based active species.

13.
Molecules ; 27(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35011406

RESUMO

The application of chitosan (CS) and whey protein (WP) alone or in combination in 3D/4D printing has been well considered in previous studies. Although several excellent reviews on additive manufacturing discussed the properties and biomedical applications of CS and WP, there is a lack of a systemic review about CS and WP bio-inks for 3D/4D printing applications. Easily modified bio-ink with optimal printability is a key for additive manufacturing. CS, WP, and WP-CS complex hydrogel possess great potential in making bio-ink that can be broadly used for future 3D/4D printing, because CS is a functional polysaccharide with good biodegradability, biocompatibility, non-immunogenicity, and non-carcinogenicity, while CS-WP complex hydrogel has better printability and drug-delivery effectivity than WP hydrogel. The review summarizes the current advances of bio-ink preparation employing CS and/or WP to satisfy the requirements of 3D/4D printing and post-treatment of materials. The applications of CS/WP bio-ink mainly focus on 3D food printing with a few applications in cosmetics. The review also highlights the trends of CS/WP bio-inks as potential candidates in 4D printing. Some promising strategies for developing novel bio-inks based on CS and/or WP are introduced, aiming to provide new insights into the value-added development and commercial CS and WP utilization.


Assuntos
Materiais Biocompatíveis , Quitosana/química , Indústria Alimentícia , Tinta , Impressão Tridimensional , Proteínas do Soro do Leite/química , Antocianinas/química , Géis/química , Probióticos/administração & dosagem , Probióticos/química
14.
J Colloid Interface Sci ; 579: 699-706, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663658

RESUMO

Fe7S8 has emerged as an attractive anode material for lithium-ion batteries (LIBs) due to its outstanding features such as low cost, high theoretical capacity, as well as environmental benignity. However, the rapid capacity fading derived from the tremendous volume change during the charging/discharging process hinders its practical application. Nanostructure engineering and the combination with carbonaceous material are essential to address this issue. In this work, Fe7S8 nanocrystals decorated on N, S-codoped carbon nanotubes (Fe7S8-NSC) were synthesized through a facile one-step pyrolysis of Fe-containing polypyrrole (PPy) nanotubes with sulphur powders under nitrogen atmosphere. When evaluated as anode of LIBs, Fe7S8-NSC demonstrates excellent cycling stability (718.8 mAh g-1 at 100 mA g-1 after 100 cycles) and superior rate ability (290.8 mAh g-1 at 2000 mA g-1). Moreover, Fe7S8-NSC shows a typical specific capacity recovery phenomenon, an extraordinary capacity of 744.4 mAh g-1 at 2000 mA g-1 after 1000 cycles can be achieved, which outperforms most of the Fe7S8-based anode materials reported before. The Fe7S8-NSC should be a promising anode material for high-performance LIBs.

15.
Food Sci Nutr ; 8(6): 2940-2949, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32566212

RESUMO

Commercial process of oat noodles was mainly hindered by its lack of gluten and difficulty in forming dough. Extrusion could be an effective method to produce oat noodles by forming network of gelatinized starch, and noodle quality could be improved by regulating the retrogradation process. In this study, we produced oat noodles by two-step extruding and investigated the effect of retrogradation treatment (retrogradation time and ambient relative humidity) on noodle properties. At each corresponding ambient relative humidity (RH), the starch crystallinity and enthalpy value increased, while setback value decreased, as well as noodle cooking loss was significantly improved as retrogradation time increased to 48 hr, and then decreased at 72 hr. At the same retrogradation time, the starch crystallinity, setback, and enthalpy value decreased to RH70% and then had a slight rise at RH80%, while noodle cooking loss with reversal trend. The retrogradation time of 48 hr and ambient RH of 60% could be an optimum treatment for effectively improving extruded oat noodle quality. Furthermore, multivariate data analysis indicated that samples at the same ambient RH tended to be clustered together. This study could provide basic knowledge for controlling processing condition of the extruded oat noodle.

16.
ACS Appl Mater Interfaces ; 12(5): 6336-6342, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31918539

RESUMO

Inspired by cytoskeletal structures that respond sensitively to environmental changes and chemical inputs, we report a strategy to trigger and finely control the assembly of stimulus-responsive DNA nanostructures with light under isothermal conditions. The strategy is achieved via integrating an upstream light-controlled, toehold-mediated DNA strand displacement circuit with a downstream DNA tile self-assembly process. By rationally designing an upstream DNA strand module, we further transform the upstream DNA strand displacement circuit to an "AND gate" circuit to control the assembly of DNA nanostructures. This example represents the demonstration of the spatial and temporal assembly of DNA nanostructures using a noninvasive chemical input. Such a light-controlled DNA logic circuit not only adds a new element to the tool box of DNA nanotechnology but also inspires us to assemble complex and responsive nanostructures.


Assuntos
DNA/química , Nanoestruturas/química , Lógica Fuzzy , Raios Ultravioleta
17.
Int J Biol Macromol ; 145: 768-776, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31866540

RESUMO

Intelligent packaging can provide better preservation and advanced convenience for consumers. In this study, corn starch and polyvinyl alcohol (PVA) were used to produce films. Two easily accessible anthocyanin sources-purple sweet potato extracts (PSPE) and red cabbage extracts (RCE), were added respectively to evaluate their potential of indicating food freshness. Film incorporated with PSPE or RCE showed distinguishable color changes in different buffers. Water vapor permeability (WVP) was not significantly (p > 0.05) affected by addition of RCE or lower level PSPE. As the extract content increased, a significant (p < 0.05) increase in thickness (from 64.0 to 97.7 or 85.5 µm with addition of PSPE or RCE, respectively), mechanical (from 7.3 to 11.3 or 9.1 MPa in TS, and from 92% to 249% or 284% in EB, added with PSPE or RCE, respectively), and thermal properties was observed, with the light transmittance reduced profoundly. PS-PSPE film exhibited bolder color, better mechanical properties and lower light transmittance than PS-RCE film at lower extract content. In addition, application for indicating shrimp freshness was conducted. The developed film presented visual color changes corresponding to TVB-N variation when shrimps were spoiled, showing its great potential as an indicator for monitoring shrimp freshness.


Assuntos
Antocianinas/química , Artemia/química , Álcool de Polivinil/química , Amido/química , Animais , Cor , Embalagem de Alimentos/métodos , Concentração de Íons de Hidrogênio , Extratos Vegetais/química , Alimentos Marinhos , Vapor
18.
ACS Omega ; 4(13): 15729-15733, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31572876

RESUMO

Plastic products have brought us great convenience in our daily life and work. But in the meantime, waste plastics have become solid pollutants in the environment due to its poor degradability. The resource utilization of waste plastic can decrease environmental pollution. Here, a thermal reduction method for the conversion of waste polyethylene to ZnCCo3 and ZnCNi3 in a stainless-steel autoclave under mild conditions has been reported. X-ray powder diffraction patterns indicate that the obtained samples are anti-perovskite-structured ternary carbides (ZnCCo3 and ZnCNi3) with good crystallinity. Moreover, the formation mechanism of ternary carbides has been briefly discussed. This method can be developed into an effective method for disposal of other waste plastics.

19.
ACS Omega ; 4(3): 4896-4900, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-31459673

RESUMO

The resource utilization of waste plastic can not only control environmental pollution but can also ease up the problems of lack of energy resources. In this study, molybdenum carbide (Mo2C) nanoparticles have been synthesized by utilizing waste polyvinyl chloride as a carbon source in a stainless-steel autoclave at 600 °C. X-ray diffraction pattern indicates that the product is orthorhombic phase Mo2C. Electron microscopy photographs show that the obtained Mo2C product consisted of crystalline nanoparticles with an average size of 50 nm. The possible formation mechanisms of Mo2C have been also briefly discussed on the basis of the structures of the products synthesized with different reaction times. The effects of reaction temperature on the crystallinity and microstructure of the obtained products have been investigated. The results show that higher reaction temperature promotes the formation of Mo2C with high crystallinity.

20.
Small ; 15(27): e1901795, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31120190

RESUMO

Biomolecular self-assembly is a powerful approach for fabricating supramolecular architectures. Over the past decade, a myriad of biomolecular assemblies, such as self-assembly proteins, lipids, and DNA nanostructures, have been used in a wide range of applications, from nano-optics to nanoelectronics and drug delivery. The method of controlling when and where the self-assembly starts is essential for assembly dynamics and functionalization. Here, train-shaped DNA nanostructures are actively self-assembled using DNA tiles as artificial "carriages," hairpin structures as "couplers," and initiators of catalytic hairpin assembly (CHA) reactions as "wrenches." The initiator wrench can selectively open the hairpin couplers to couple the DNA tile carriages with high product yield. As such, DNA nanotrains are actively prepared with two, three, four, or more carriages. Furthermore, by flexibly modifying the carriages with "biotin seats" (biotin-modified DNA tiles), streptavidin "passengers" are precisely arranged in corresponding seats. The applications of the CHA-triggered self-assembly mechanism are also extended for assembling the large DNA origami dimer. With the creation of 1D architectures established, it is thought that this CHA-triggered self-assembly mechanism may provide a new element of control for complex autonomous assemblies from a variety of starting materials with specific sites and times.


Assuntos
DNA/química , Nanoestruturas/química , Conformação de Ácido Nucleico , Catálise , Dimerização
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA