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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120232, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352500

RESUMO

To achieve the ultrastable LMOFs with predominant luminescent sensing performances, the aromatic π-electron mixed ligands strategy was introduced, and the ternary LMOF of {[Zn2(HDDB)(bib)1.5]·3H2O}n (1), was fabricated based on 3,5-di(2',4'-dicarboxylphenyl)benozoic acid (H5DDB) and the N-donor of meta-bis(imidazol-1-yl)benzene (bib) under mixed solvothermal condition. LMOF 1 features the first reported 3D 3,4,4-c {62.83.10}{62.8}2{63.82.10}2 framework with 21.2 % porosity as well as high thermal and chemical stability. Further luminescent sensing showed that LMOF 1 as a bifunctional chemosensor possessing predominant detectability for sensitive detect the hexavalent chromates and nitroimidazoles/nitrofurans antibiotics in water through strong luminescent quenching effects, with excellent reusability as well as trace detection limits. Moreover, luminescent quenching mechanisms were further investigated from electron transfer and energy transfer viewpoints.

2.
Front Pharmacol ; 12: 738630, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34630113

RESUMO

Photothermal therapy (PTT) has become effective method for the treatment of malignant cancer. The development of PTT system with high anti-tumour effect is still the feasible research direction. Here, a new type of gold nanorods (AuNRs)-doxorubicin (DOX)/mPEG10K-peptide/P(AAm-co-AN) (APP-DOX) nano drug delivery system was proposed. Among them, AuNRs was used as high-efficiency photothermal agent. APP-DOX had a suitable size and can be targeted to accumulate in tumour tissues through circulation in the body. The abundant matrix metalloproteinase 2 (MMP-2) in the tumour environment intercepted and cut off the short peptide chain structure grafted on APP-DOX. At the same time, the removal of the PEG segment leaded to an increase in the hydrophobic properties of the system. Nanoparticles aggregated into large particles, causing them to stay and aggregate further at the tumour site. When irradiated by 808 nm near-infrared laser, APP-DOX achieved a gradual heating process. High temperature can effectively ablate tumours and enable UCST polymer to achieve phase transition, resulting in more anti-cancer drugs loaded in the polymer layer DOX was released, effectively killing cancer cells. Animal experiments had verified the possibility of the nano drug-carrying system and good tumour treatment effect. What's more worth mentioning is that compared with free DOX, the nano drug delivery system had lower biological toxicity and not cause obvious harmful effects on normal organs and tissues.

3.
Materials (Basel) ; 14(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34639878

RESUMO

In this research, the sustainable applications for utilizing antimony tailing coarse aggregate (ATCA) in concrete is investigated. Comprehensive verifications were performed by a series of experiments on the characteristic of ATCA and the toxicity risks of concrete. Firstly, a real case study of utilization of ATCA as a complete substitute for natural coarse aggregate (NCA) in high strength concrete was conducted. Then, chemical composition of ATCA was tested. It is demonstrated that the essential mineral is SiO2 and the lithology of ATCA is quartzite. The mechanical properties, coarse quality of ATCA, and NCA were studied and compared. The compressive strength, splitting tensile strength, and compressive elastic modulus of ATWR are 221.51 MPa, 5.93 MPa, and 3.33 × 104 MPa, which are 1.31, 2.22, 1.40 times of that of NR, respectively. All of the quality control indices of ATCA meet the requirements of the current industry standards of China. Finally, the toxicity risks of ATCA concrete were investigated. It is illustrated that the leaching of main heavy metals including Sb, As, Hg, Pb, Cd, and Zn in the ATCA concrete under different pH conditions are below the regulatory limits. The utilization of antimony tailing has significant environmental and economic benefits.

4.
Front Cell Dev Biol ; 9: 687258, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34604210

RESUMO

Mesenchymal stem cells (MSCs) are intrinsically heterogeneous and are comprised of distinct subpopulations that differ in their differentiation potential. A deeper understanding of the heterogeneity and intercellular communication within these heterogeneous subpopulations has significant implications for the potential of MSC-based therapy from the bench to the clinic. Here, we focused on the clonal osteogenic heterogeneity of periodontal ligament stem cells (PDLSCs) and explored how interclonal communication affects the osteogenic differentiation among these heterogeneous single-cell colonies (SCCs), and sought to determine the underlying mechanisms. Alkaline phosphatase (ALP) and Alizarin red staining identified the presence of SCCs with high (H-SCCs) and low osteogenic ability (L-SCCs). Conditioned medium derived from H-SCCs (H-CM) promoted mineralized nodule formation to a greater extent than that derived from L-SCCs (L-CM), which served as the target cells (TCs). However, treatment with the exosome biogenesis/release inhibitor GW4869 reduced the H-CM- and L-CM-related osteogenic differentiation-promoting potential. We further found that exosomes secreted by H-SCCs (H-Exo) were superior to those secreted by L-SCCs (L-Exo) in promoting the osteogenic differentiation of TCs. Mechanistically, TCs stimulated with H-CM and H-Exo exhibited higher levels of PINK1/Parkin-mediated mitophagy, while gain- and loss-of-function experiments showed that PINK1/Parkin-mediated mitophagy was positively associated with SCC osteogenic differentiation. Furthermore, PINK1 knock-down in H-Exo- and L-Exo-stimulated TCs inhibited their osteogenic differentiation through inhibiting PINK1/Parkin-mediated mitophagy. Our study uncovers a previously unrecognized mechanism that an exosome-mediated PINK1/Parkin-dependent mitophagy regulates interclonal communication among SCCs with osteogenic heterogeneity.

5.
Front Genet ; 12: 722208, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659344

RESUMO

The lack of an accurate biomarker in hepatocellular carcinoma (HCC) has hindered early detection, diagnosis, and treatment. Circular RNAs (circRNAs), which can be used as novel biomarkers in liquid biopsies, have been brought to light as a result of the advances in research on molecular biomarkers and the progression of genomic medicine. We conducted a meta-analysis of the diagnostic accuracy of serum/plasma circRNAs or the combination of circRNAs and α-fetoprotein (AFP) in HCC. We identified eight studies that met the inclusion/exclusion criteria from PubMed, Web of Science, EMBASE, and Cochrane Library databases. The data were pooled, and the sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) with 95% confidence intervals (CIs) were calculated. The areas under the summary receiver operator characteristic (SROC) curves (AUCs) were also calculated. The sensitivity of circRNAs was 0.82 (95% CI: 0.78-0.85), and the specificity was 0.82 (95% CI: 0.78-0.86). The sensitivity of AFP was 0.65 (95% CI: 0.61-0.68), and the specificity was 0.90 (95% CI: 0.85-0.93). The AUC was 0.89 (95% CI: 0.86-0.91) for circRNAs and 0.77 (95% CI: 0.74-0.81) for AFP. The sensitivity of the combination of circRNAs and AFP was 0.88 (95% CI: 0.84-0.92), specificity was 0.86 (95% CI: 0.80-0.91), and AUC was 0.94 (95% CI: 0.91-0.96). Additionally, a subgroup analysis was conducted based on the control groups used; the diagnostic accuracy was particularly high in the comparison of HCC vs. healthy controls. In summary, serum/plasma circRNAs are accurate biomarkers suitable for clinical use for detecting HCC, and the combination of circRNAs and AFP improved the diagnostic accuracy.

6.
Nanomaterials (Basel) ; 11(10)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34685081

RESUMO

We developed a simple method to fabricate SiO2-sphere-supported N-doped CNTs (NCNTs) for electromagnetic wave (EMW) absorption. EMW absorption was tuned by adsorption of the organic agent on the precursor of the catalysts. The experimental results show that the conductivity loss and polarization loss of the sample are improved. Meanwhile, the impedance matching characteristics can also be adjusted. When the matching thickness was only 1.5 mm, the optimal 3D structure shows excellent EMW absorption performance, which is better than most magnetic carbon matrix composites. Our current approach opens up an effective way to develop low-cost, high-performance EMW absorbers.

7.
Chem Commun (Camb) ; 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34652356

RESUMO

Photothermal therapy (PTT) achieves substantive therapeutic progress in certain tumor types without exogenous agents but is hampered by the over-activated inflammatory response or tumor recurrence in some cases. Herein, we technically developed the metal-polyphenolic nanosystem with precise NIR-II fluorescence-imaging guidance for combining hafnium (Hf)-sensitized radiotherapy with PTT to regress tumor growth.

8.
Nat Commun ; 12(1): 5733, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593794

RESUMO

In addition to increasing the expression of programmed death-ligand 1 (PD-L1), tumor cells can also secrete exosomal PD-L1 to suppress T cell activity. Emerging evidence has revealed that exosomal PD-L1 resists immune checkpoint blockade, and may contribute to resistance to therapy. In this scenario, suppressing the secretion of tumor-derived exosomes may aid therapy. Here, we develop an assembly of exosome inhibitor (GW4869) and ferroptosis inducer (Fe3+) via amphiphilic hyaluronic acid. Cooperation between the two active components in the constructed nanounit induces an anti-tumor immunoresponse to B16F10 melanoma cells and stimulates cytotoxic T lymphocytes and immunological memory. The nanounit enhances the response to PD-L1 checkpoint blockade and may represent a therapeutic strategy for enhancing the response to this therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Portadores de Fármacos/química , Exossomos/efeitos dos fármacos , Ferroptose/efeitos dos fármacos , Melanoma Experimental/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Compostos de Anilina/farmacologia , Compostos de Anilina/uso terapêutico , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Compostos de Benzilideno/farmacologia , Compostos de Benzilideno/uso terapêutico , Linhagem Celular Tumoral/transplante , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/imunologia , Exossomos/imunologia , Exossomos/metabolismo , Feminino , Ferroptose/imunologia , Humanos , Ácido Hialurônico/química , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Memória Imunológica , Ativação Linfocitária/efeitos dos fármacos , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Evasão Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia
9.
Adv Healthc Mater ; : e2101586, 2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34601825

RESUMO

Pathological mineralization (PTM) often occurs under inflammation and affects the prognosis of diseases, such as atherosclerosis and cancers. However, how the PTM impacts inflammation has not been well explored. Herein, poly lactic-co-glycolic acid (PLGA)/gelatin/hydroxyapatite (HA) electrospun nanofibers are rationally designed as an ideal PTM microenvironment biomimetic system for unraveling the role of PTM on inflammation. The results demonstrate that the inflammatory response decreases continuously during the process of mineralization. When mature macromineralization forms, the inflammation almost completely disappears. Mechanistically, the PTM formation is mediated by matrix proteins, local high calcium, and cell debris (nuclei), or actively regulated by the lysosomal/plasma membrane components secreted by macrophages. These inflammatory inducible factors (calcium, cell debris, etc.) can be "buried" through PTM process, resulting in reduced immune responses. Overall, the present study demonstrates that PTM is an innate mechanism of inflammation subsidence, providing valuable insight into understanding the action of mineralization on inflammation.

10.
Dalton Trans ; 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622897

RESUMO

Luminescent metal-organic frameworks (LMOFs) as chemosensors, can sense various analytes, such as heavy metal ions, antibiotics, pesticides, and small biological molecules. Based on the fluorescence characteristics of LMOFs, a variety of logic gates have been developed. In this review, we mainly discuss some common logic systems based on LMOFs, and then summarize the strategies of constructing logic gates from two perspectives. One is based on superior characteristics of MOFs, which can be synthesized from Ln3+ based MOFs (Ln-MOFs) or form hybrids by encapsulating different materials, including metal ions, dyes, and quantum dots (QDs). The other is to control the presence of inputs by reactions between different reactants and then further control switches of logic gates. Additionally, the common sensing mechanisms of LMOFs in logic gates are discussed. In the end, we have envisioned MOFs that possess a promising future in logic computing areas.

11.
ACS Nano ; 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34661387

RESUMO

Nanomedicine has revolutionized cancer therapeutic strategies but has not completely changed the outcomes of tricky tumors that evolve a sophisticated immunosuppressive tumor microenvironment (TME) such as acidification. Here, a metal-phenolic network-based nanocomplex embedded with lactate oxidase (LOX) and a mitochondrial respiration inhibitor atovaquone (ATO) was constructed for immunosuppressive TME remodeling and sonodynamic therapy (SDT). In this nanocomplex, the sonosensitizer chlorin e6-conjugated polyphenol derivative can induce the generation of tumor lethal reactive oxygen species upon ultrasound irradiation. LOX served as a catalyst for intracellular lactic acid exhaustion, and ATO led to mitochondrial dysfunction to decrease oxygen consumption. This nanocomplex reversed the tumor immunosuppressive status by alleviating tumor hypoxia and acidic TME, achieving the characteristic enhancement of SDT and the inhibition of tumor proliferation and metastasis.

12.
Pest Manag Sci ; 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34469049

RESUMO

BACKGROUND: The Asian lady beetle Harmonia axyridis is an important predator of several agricultural pests, including aphids and whiteflies, and thus can contribute to pest management. Commercial viability as a pest control method requires that the beetle can be mass-reared, and that workable conditions for extended shelf-life can be guaranteed. One of the features of Harmonia's life cycle is that it enters diapause in the adult stage when the length of the photophase starts shortening in late summer. Reduction of juvenile hormone (JH) titer has been demonstrated to be the common endocrine mechanism inducing reproductive diapause in insects. However, whether H. axyridis enters diapause dependent on JH shutdown and how the JH level is regulated before diapause remains unknown. RESULTS: Like in other insects, the absence of JH triggers the induction and maintenance of reproductive diapause in H. axyridis, indicated by JH measurements and the knockdown of an intracellular JH receptor methoprene-tolerant (Met). Methoprene, a JH analog, significantly reversed diapause into reproduction via Met. Combined with RNA-sequencing and RNA interference, we also demonstrated that JH biosynthesis rather than the JH degradation pathway determines the reduction of JH titer in diapausing females. CONCLUSION: Our results reveal the vital role of JH in regulating reproductive diapause in female H. axyridis. Harmonia axyridis diapause could thus be manipulated by targeting JH production and JH signaling.

13.
Autoimmunity ; : 1-10, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499003

RESUMO

Infantile pneumonia is a common inflammatory disease with the infections of various pathogens in lower respiratory tracts. Here, the role and working mechanism of circular RNA (circRNA) ubiquinol-cytochrome c reductase core protein 2 (circ-UQCRC2; hsa_circ_0038467) in infantile pneumonia were investigated. Cell viability, apoptosis, and inflammatory response were assessed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). Cell oxidative stress was analyzed by measuring the production of malondialdehyde (MDA) and superoxide dismutase (SOD). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were performed to determine the expression of RNAs and proteins. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to confirm the interaction between microRNA-495-3p (miR-495-3p) and circ-UQCRC2 or myeloid differentiation primary response protein 88 (MYD88). Lipopolysaccharide (LPS) treatment suppressed the viability while induced the apoptosis, inflammation, and oxidative stress of 16HBE cells in a dose-dependent manner. LPS exposure dose-dependently up-regulated the expression of circ-UQCRC2 in 16HBE cells. Circ-UQCRC2 absence attenuated LPS-induced injury in 16HBE cells. miR-495-3p was a target of circ-UQCRC2, and circ-UQCRC2 silencing-mediated protective effects in LPS-induced 16HBE cells were partly reversed by anti-miR-495-3p. MYD88 was a target of miR-495-3p, and MYD88 overexpression partly counteracted miR-495-3p accumulation-mediated influences in 16HBE cells upon LPS exposure. Circ-UQCRC2 interference decreased the protein expression of MYD88 partly by up-regulating miR-495-3p in LPS-induced 16HBE cells. In conclusion, circ-UQCRC2 contributed to LPS-induced injury of 16HBE cells by targeting miR-495-3p/MYD88 signalling-mediated inflammatory response and oxidative stress.

14.
Nanoscale ; 13(37): 15647-15658, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34532728

RESUMO

Nanocapsules are a promising controlled release formulation for foliar pest control. However, the complicated process and high cost limit widespread use in agriculture, so a simpler and more convenient preparation system is urgently needed. Meanwhile, under complex field conditions, the advantageous mechanism of the nanosize effect and sustained release have no quantitative and detailed study. In this study, a reactive emulsifier (OP-10) is used to participate in the interfacial polymerization of the nanoemulsion, and polymer nanocapsules loaded with lambda-cyhalothrin (NCS@LC) are quickly and easily prepared to study the efficacy and synergistic mechanism of foliar pest control. As a result, the nanocapsule is about 150 nm with a stable core-shell structure. The nanoscale state increases the distribution and adhesion of the particles on the leaf surface, which increases the contact efficiency of pesticides under the different physiological stages and behavioral activities of the target organism. The shell structure provides sustained release characteristics and increases the UV resistance by about 2.5 times for pesticides. Compared with microcapsules loaded with lambda-cyhalothrin (CS@LC), NCS@LC not only shows rapid and synergistic insecticidal efficacy but also provides sustained insecticidal efficacy. The mortality of NCS is 3.4 times that of the nanosized emulsion in water (NEW) at the lowest concentration (0.5 mg L-1), and the control efficacy remained 77.3% after 7 days. Compared with NEW, NCS@LC provides excellent field efficacy, while LC50 for zebrafish is only 0.68 times without increasing the aquatic toxicity risk.


Assuntos
Inseticidas , Nanocápsulas , Piretrinas , Animais , Nanocápsulas/toxicidade , Nitrilas , Peixe-Zebra
15.
Bioengineered ; 12(1): 7188-7204, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34546854

RESUMO

Oral squamous cell carcinoma (OSCC) poses a threat to public health worldwide. LncRNA APCDD1L-AS1 has been reported to participate in tumorigenesis and development of acquired chemoresistance. However, the role of APCDD1L-AS1 in 5-fluorouracil (5-FU) resistance regulation within OSCC is still obscure. In this study, 5-FU-resistant cell models were established with OSCC cell lines (HSC-3 and HN-4). Gene expressions and protein levels were detected by RT-qPCR and Western blotting, respectively. CCK-8, colony forming, and flow cytometry were utilized to measure IC50 value, cell viability, and cell apoptosis of 5-FU-resistant OSCC cells. Dual-luciferase reporter assay and RIP assay were applied to identify the associations between miR-1224-5p and APCDD1L-AS1 or NSD2. Herein, high APCDD1L-AS1 expression was shown in OSCC tissues and cells resistant to 5-FU and related to the worse prognosis of OSCC patients. APCDD1L-AS1 knockdown impaired 5-FU resistance in 5-FU-resistant OSCC cells by reducing IC50 value, suppressing cell viability, and accelerating cell apoptosis. Besides, extracellular APCDD1L-AS1 could be transferred to sensitive cells via exosome incorporation, thereby transmitting 5-FU resistance in OSCC cells. Besides, miR-1224-5p was a molecular target of APCDD1L-AS1 and directly targeted NSD2 in 5-FU-resistant cells. MiR-1224-5p exhibited a much lower level in 5-FU-resistant tissues and increased 5-FU sensitivity in 5-FU-resistant OSCC cells. Moreover, NSD2 upregulation neutralized the influence of blocking APCDD1L-AS1 in HSC-3/5-FU and HN-4/5-FU cells on 5-FU resistance. To sum up, our study demonstrated that exosomal APCDD1L-AS1 conferred resistance to 5-FU in HSC-3/5-FU and HN-4/5-FU cells via the miR-1224-5p/NSD2 axis, thus providing a novel target for OSCC chemoresistance.

16.
J Plant Physiol ; 266: 153510, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34521019

RESUMO

Source sink balance is one of the major determinants of carbon partitioning in plants. However, its effects on photosynthesis in fruit trees are largely unknown. In this work, the effects of low sink demand on net photosynthetic rate (Pn) and chlorophyll fluorescence after fruit removal (-fruit) in peach (Prunus persica (L.) Batsch cv. 'Zaojiubao') trees were investigated. The stepwise energy flow through photosystem II (PSII) at the reaction center (RC) was analyzed with quantitative analyses of fluorescence transient, also called JIP-test. We found that Pn was significantly lower and closely correlated to the leaf stomatal conductance (Gs) of -fruit trees than that of fruit retained (+fruit) trees. Leaf temperature (Tleaf) of -fruit trees was remarkably higher than that of +fruit trees. Day-time-period assays of chlorophyll (Chl) fluorescence revealed that, in the leaves of -fruit trees, the fluorescence parameters, such as NPQ (non-photochemical quenching coefficient) and ΦD0 (maximum quantum yield of non-photochemical de-excitation), decreased in the morning and recovered to the normal level in the afternoon, whereas other parameters, such as ΦE0 (quantum yield for electron transport at t = 0), Ψ0 (probability that a trapped exciton moves an electron to QA pool), F0 (minimum fluorescence, when all PSII RCs are open) and Wk (relative variable fluorescence at 300 µs of the chlorophyll fluorescence transient), did not. These results suggest that OEC complex and QA pool were irreversibly affected by low sink demand, whereas light harvest antenna and PSII potential efficiency retained a strong ability to recover.

17.
J Mech Behav Biomed Mater ; 124: 104830, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34530300

RESUMO

In this work, molecular dynamics simulations are conducted to investigate the structural and mechanical properties of dental materials, i.e., the silica nanorod reinforced Bis-GMA/TEGDMA resin composite. The effects of loading content and size of the silica nanorods on the composite stiffness were performed by examining resin chain conformation, hydrogen bonds and matrix/filler binding energy. It is revealed that the presence of the silica nanorod causes polymer chain expansion, endowing the resins with higher stiffness. Moreover, the volumetric hydrogen bonds and binding energy increase considerably with the loading content, but decrease gradually with the diameter or show almost independence of the length. Furthermore, the composite moduli were quantified by the micromechanics models and the transverse moduli were well predicted by the Counto model, signifying a perfect bonding between the matrix and nanorod. The chain expansion and energetic matrix/filler interactions are believed to contribute to the significant mechanical reinforcement of the composites with the loading content. However, the length of the nanorod has a little effect on the composite moduli due to the unaltered interfacial interaction. In contrast, a smaller diameter is supposed to give a larger modulus, and this is not observed in this work due to the synergic effects of improved matrix/filler interaction and actual reduced filler volume fraction. The mechanical enhancement by the rod-like structures is more influenced by the loading content, but less so by the size of the nanorod, and it also exhibits superior mechanical performance as compared to nanoparticles. The findings thus extend the current understanding of the nanostructure and mechanical properties of silica nanorod reinforced dental resin composites from an atomic/molecular perspective.

18.
J Mol Model ; 27(10): 288, 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34536146

RESUMO

Synthesis of magnetic nanoparticles is relevant to many applications in the fields of catalysis, energy storage, and biomedicine. Understanding the growth mechanisms and morphology of nanoparticles during inert gas condensation is crucial to rationally improve the performance of the final nanoparticles. In this work, molecular dynamics simulations are carried out to study the structural and thermodynamic behavior of Ni-Fe nanoparticles from homogenous vapor phase in Ar atmosphere. It is revealed that the final morphology of the resulting nanoparticles presents a spherical shape by cluster coalescence at high temperatures where the small clusters are liquid droplets prior to their collisions. However, probabilistic nucleation and cluster growth indicate that the occurrence of spherical shape is more controlled by the probability limits for different Fe concentrations. Meanwhile, a larger inert gas density induces a more efficient cooling effect leading to a larger probability control of the cluster formation with non-spherical shape by agglomeration. Furthermore, the solidification of the as-formed Ni-Fe clusters is examined by evaluating the evolution of crystalline and amorphous structure. The linear scaling-down dependence of the solidification temperature on the reciprocal of the nanoparticle size clearly signifies a linear size-depression effect for the liquid-to-solid phase change of Ni-Fe nanoparticles. Our findings thus extend the current understanding of inert gas condensation behavior and mechanisms of Ni-Fe nanoparticles from an atomic/molecular perspective.

19.
Zhongguo Gu Shang ; 34(8): 773-9, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34423624

RESUMO

OBJECTIVE: To compare the clinical efficacy of staged surgery on Sanders Ⅳ calcaneal fractures with soft tissue Ⅲ swelling. METHODS: The clinical data of 76 patients with Sanders type Ⅳ closed calcaneal fracture with soft tissue three-degree swelling treated from June 2017 to May 2020 was retrospectively analyzed, including 54 males and 22 females, aged from 25 to 50 (38.16±10.24) years. The patients were divided into observation group and control group according to different treatment methods. Twenty-four patients in the observation group were treated by staged surgery stageⅠclosed prying traction reduction and Kirschner wire fixation, stageⅡopen reduction and internal fixation with titanium plate, including 17 males and 7 females, aged from 25 to 50 (36.12±9.56) years. There were 52 patients in the control group, including 37 males and 15 females, aged from 25 to 50 (38.32±10.67) years, these patients were treated with open reduction and internal fixation with titanium plate after the dermatoglyphic signs appeared. The swelling subsidence time, the length of hospitalization days, and the incidence of postoperative incision complications were compared between two groups. The Bhler angle, Gissane angle, and calcaneal varus angle were measured by X-ray before and 6 months after operation. American Orthopedic Foot and Ankle Society (AOFAS) about the ankle hindfoot score was used to evaluate the clinical efficacy. RESULTS: All 76 patients were followed up for 8 to 12 (9.52±2.01) months. The swelling subsidence time and hospitalization days in observation group were (12.12± 3.24) d and (24.53±6.44) d, respectively, which in control group were (15.16±4.16) d and (29.46±9.61) d, with statistical difference between two groups (P<0.05). Postoperative 6 months, Bhler angle, Gissane angle and calcaneal varus angle were (31.33±10.15)°, (145.34±8.04) ° and (10.31±3.23) ° in observation group, while those in control group were (20.24±8.23) °, (165.28±10.29) °and (21.24±5.27) °, with statistical difference between two groups (P<0.05). And there was significant difference in all patients between before and 6 months after operation (P<0.05). The AOFAS score of the observation group and control group were 71.76±9.84 and 57.23±10.76 at 6 months after operation, with significant different between two groups (P< 0.05). The excellent rate of observation group was significantly higher than that of control group (P<0.05). CONCLUSION: Compared with open reduction and internal fixation with titanium plate after the appearance of dermatoglyphic signs, staged surgery for Sanders type Ⅳ calcaneal fractures with soft tissue three-swelling does not increase the risk of soft tissue complications, and can significantly shorten the patient's swelling subsidence time and hospitalization days, improve the quality of fracture reduction and short term function, and relieve pain.


Assuntos
Traumatismos do Tornozelo , Calcâneo , Traumatismos do Pé , Fraturas Ósseas , Calcâneo/cirurgia , Feminino , Fraturas Ósseas/cirurgia , Humanos , Masculino , Estudos Retrospectivos
20.
BMC Public Health ; 21(1): 1527, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34372799

RESUMO

BACKGROUND: In this research, the factors that influence the self-precautionary behavior during the pandemic are explored with the combination of social support and a risk perception attitude framework. METHODS: An online survey was conducted among 429 members to collect information on demographic data, social support, perceptions of outbreak risk, health self-efficacy, and self-precautionary behaviors with the guide of the Social Support Scale, the COVID-19 Risk Perception Scale, the Health Self-Efficacy Scale and the Self-precautionary Behavior Scale. RESULTS: The research shows that among the three dimensions of social support, both objective support and support utilization negatively predict risk perception, while subjective support positively predicts health self-efficacy; health self-efficacy and risk perception significantly predict self-precautionary behavior; the relationship between risk perception and self-precautionary behavior is significantly moderated by health self-efficacy. CONCLUSIONS: The combined influence of social capital and risk perception attitudinal frameworks on self-precautionary behavior is highlighted in this study, with the relationship between the public's risk perception, health self-efficacy, and self-precautionary behavior intentions examined against the background of coronavirus disease 2019 (COVID-19). These findings contribute to understanding the impact of social capital factors on risk perception and health self-efficacy, which provides insight into the current status and influencing factors of the public's precautionary behavior and facilitates early intervention during a pandemic.


Assuntos
COVID-19 , Pandemias , Estudos Transversais , Humanos , Percepção , SARS-CoV-2 , Apoio Social , Inquéritos e Questionários
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