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1.
Lab Chip ; 24(4): 832-842, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38235769

RESUMO

Magnetically-actuated microrobots (MARs) exhibit great potential in biomedicine owing to their precise navigation, wireless actuation and remote operation in confined space. However, most previously explored MARs unfold the drawback of hypodynamic magnetic torque due to low magnetic content, leading to their limited applications in controlled locomotion in fast-flowing fluid and massive cargo carrying to the target position. Here, we report a high-performance pure-nickel magnetically-actuated microrobot (Ni-MAR), prepared by a femtosecond laser polymerization followed by sintering method. Our Ni-MAR possesses a high magnetic content (∼90 wt%), thus resulting in enhanced magnetic torque under low-strength rotating magnetic fields, which enables the microrobot to exhibit high-speed swimming and superior cargo carrying. The maximum velocity of our Ni-MAR, 12.5 body lengths per second, outperforms the velocity of traditional helical MARs. The high-speed Ni-MAR is capable of maintaining controlled locomotion in fast-flowing fluid. Moreover, the Ni-MAR with massive cargo carrying capability can push a 200-times heavier microcube with translation and rotation motion. A single cell and multiple cells can be transported facilely by a single Ni-MAR to the target position. This work provides a scheme for fabricating high-performance magnetic microrobots, which holds great promise for targeted therapy and drug delivery in vivo.

2.
Chemosphere ; 350: 141052, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38160956

RESUMO

Exploring novel water purifier to efficiently remove heavy metal ions from the wastewater is of vital importance. Inspired by the hierarchical structure of natural wood and the chelation of amino group, a high-efficiency water purifier with ethylenediamine functionalized MIL-101(Cr) octahedrons anchored on the wood aerogel (MIL-101(Cr)-ED/WA) was constructed. Benefiting from the two-pronged approach with the hierarchical structure of the wood aerogel frame for multistage filtration and the -NH2 that capable of chelation with metal ions, the fabricated MIL-101(Cr)-ED/WA exhibits excellent water purification performances, and its adsorption capacity of toxic Pb2+ ions could reach up to 6.46 mmol g-1. Furthermore, it demonstrates superior recyclability without secondary pollution and is also suitable for simultaneous treatment of multiple metal species. In general, this work will broaden the utilization of wood-based structural engineering materials in the treatment of heavy metal wastewater.


Assuntos
Estruturas Metalorgânicas , Metais Pesados , Poluentes Químicos da Água , Águas Residuárias , Madeira , Poluentes Químicos da Água/química , Metais Pesados/química , Adsorção , Água , Íons/química
3.
Anal Chim Acta ; 1278: 341687, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37709427

RESUMO

Aflatoxin B1 is a carcinogenic contaminant in food or feed, and it poses a serious health risk to humans. Herein, a computer vision-assisted smartphone microscope imaging digital (SMID) immunosensor based on the click chemistry-mediated microsphere counting technology was designed for the detection of aflatoxin B1 in peanuts. In this SMID immunosensor, the modified polystyrene (PS) microspheres were used as the signal probes and were recorded by a smartphone microscopic imaging system after immunoreaction and click chemistry reaction. The number of PS probes is adjusted by aflatoxin B1. The customized computer vision procedure was used to efficiently identify and count the obtained PS probes. This SMID immunosensor enables sensitive detection of aflatoxin B1 with a linear range from 0.001 ng/mL to 500 ng/mL, providing a simple, sensitive, and portable tool for food safety supervision.


Assuntos
Arachis , Técnicas Biossensoriais , Humanos , Aflatoxina B1 , Microesferas , Smartphone , Química Click , Imunoensaio , Tecnologia
4.
Gels ; 8(11)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36421566

RESUMO

SiO2 aerogels have attracted extensive attention due to their unique structural characteristics, which exhibit many special properties, especially good optical transparency. As far as we know, the sol-gel stage during the synthesis of aerogel plays an important role in the construction of the gel skeleton. In this study, we adjusted the amount of silicon source and catalyst to explore the best scheme for preparing highly transparent SiO2 aerogels, and further clarify the effects of both on the properties of SiO2 aerogels. Results indicated that the pore size distribution was between 10 and 20 nm, the thermal conductivity was between 0.0135 and 0.021 W/(m·K), and the transmittance reached 97.78% at 800 nm of the aerogels, better than most studies. Therefore, it has the potential to be used in aerogel glass for thermal insulation.

5.
Polymers (Basel) ; 14(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36297922

RESUMO

Endowing epoxy resin (EP) with prospective liquid oxygen compatibility (LOC) as well as enhanced ultra-low-temperature mechanical properties is urgently required in order to broaden its applications in aerospace engineering. In this study, a reactive phosphorus/nitrogen-containing aromatic ethylenediamine (BSEA) was introduced as a reactive component to enhance the LOC and ultra-low-temperature mechanical properties of an EP/biscitraconimide resin (BCI) system. The resultant EP thermosets showed no sensitivity reactions in the 98J liquid oxygen impact test (LOT) when the BSEA content reached 4 wt% or 5 wt%, indicating that they were compatible with liquid oxygen. Moreover, the bending properties, fracture toughness and impact strength of BSEA-modified EP were greatly enhanced at RT and cryogenic temperatures (77 K) at an appropriate level of BSEA content. The bending strength (251.64 MPa) increased by 113.67%, the fracture toughness (2.97 MPa·m1/2) increased by 81.10%, and the impact strength (31.85 kJ·m-2) increased by 128.81% compared with that of pure EP at 77 K. All the above results demonstrate that the BSEA exhibits broad application potential in liquid oxygen tanks and in the cryogenic field.

6.
Ultrason Sonochem ; 77: 105672, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34330083

RESUMO

It is well-known that ultrasound has been studied for its cavitation, mechanical and thermal effects. As a pretreatment technology, ultrasonic alkali treatment has attracted much attention in the field of biomass biochemical transformation. In this study, the structural and dynamic changes of wood cell walls during ultrasound-water, alkali, and ultrasound-alkali treatments were investigated by stereoscopic microscopy, confocal Raman microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. The results indicated that the ultrasound-water, alkali, and ultrasound-alkali treatments had the effect of removing extractives from conduits. The uniform self-shrinking samples with shrinkage conduits were obtained by the alkali and ultrasound-alkali treatments. All of the treatments affected the relative content, structure and distribution of the chemical components in the wood cell walls. Compared with water-immersion samples, the relative content of hemicellulose of the treated samples reduced from 32.31% to 7.02% for ultrasound-8% NaOH treated samples. For the signal intensity of lignin, ultrasound-water treated and ultrasound-alkali treated samples displayed a more significant reductions than the alkali treated samples in the cell wall region. The crystal zone and amorphous zone of cellulose coexisted before and after the treatment, for all of the treated samples, and particularly for the ultrasound-assisted treated samples, the crystallinity increased from 38.15% for water-immersion samples to 57.42% for ultrasound-8% NaOH treated samples.


Assuntos
Álcalis/química , Parede Celular/química , Parede Celular/metabolismo , Ondas Ultrassônicas , Água/química , Linhagem Celular , Polissacarídeos/análise
7.
Brain Imaging Behav ; 15(5): 2464-2471, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33479923

RESUMO

The present study aimed to explore associations between brain activity in the auditory cortex and clinical and psychiatric characteristics in patients with migraine without aura (MwoA) during interictal periods. Resting-state data were acquired from patients with episodic MwoA (n = 34) and healthy controls (n = 30). Independent component analysis was used to extract and calculate the resting-state auditory network. Subsequently, we analyzed the correlations between spontaneous activity in the auditory cortex and clinical and psychiatric features in interictal MwoA. Compared with healthy controls, patients with MwoA showed increased activity in the left superior temporal gyrus (STG), postcentral gyrus (PoCG) and insula. Brain activity in the left STG was positively correlated with anxiety scores, and activity in the left PoCG was negatively correlated with anxiety and depression scores. No significant differences were found in intracranial volume between the two groups. This study indicated that functional impairment and altered integration linked to the auditory cortex existed in patients with MwoA in the interictal period, suggesting that auditory-associated cortex disruption as a biomarker may be implemented for the early diagnosis and prediction of neuropsychiatric impairment in interictal MwoA patients.


Assuntos
Epilepsia , Enxaqueca sem Aura , Encéfalo/diagnóstico por imagem , Córtex Cerebral , Humanos , Imageamento por Ressonância Magnética , Enxaqueca sem Aura/diagnóstico por imagem , Enxaqueca sem Aura/epidemiologia
8.
Sci Rep ; 10(1): 6760, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317739

RESUMO

To improve the performance of bamboo and increase its utilization value, this study aimed at investigating the effects of impregnation pretreatment and thermal treatment on the structural changes of bamboo. The samples were pretreated in sodium hydroxide or zinc chloride solution, and then treated at 160 °C. The pretreated and control samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG), and Fourier transform infrared spectroscopy (FTIR). The results showed that the cellulose crystallinity and intensity of samples pretreated by ZnCl2 could be reduced, but the crystal structure remained the same. As for samples pretreated in NaOH, the crystal structure of fiber was destroyed and the crystallinity was increased significantly. High temperature treatment has little effect on the thermal stability of bamboo. However, after treatment with NaOH and ZnCl2, the thermal degradation temperature changed obviously and moved to a lower temperature. ZnCl2 pretreatment had influence on the chemical structure of bamboo, while NaOH pretreatment had greater influence on the chemical structure of bamboo.


Assuntos
Celulose/química , Fibras na Dieta/metabolismo , Sasa/química , Ácidos/farmacologia , Álcalis/farmacologia , Celulose/ultraestrutura , Temperatura Alta , Hidrólise/efeitos dos fármacos , Sasa/ultraestrutura , Hidróxido de Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
RSC Adv ; 10(21): 12492-12503, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35497629

RESUMO

Toxicity and environmental issues have elicited research attention regarding the need to prepare a green flame retardant with high flame retardancy. Here, a supermolecular self-assembly technology was used to prepare nickel phytate as shell materials aggregated on aminated silica nanotemplates through electrostatic interactions as a green novel flame retardant (Ni@SiO2-PA). After incorporating the obtained core-shell structured Ni@SiO2-PA into epoxy resin (EP), the supermolecular shell effectively enhanced the adhesive property between the nanoparticles and the EP matrix. The thermal stability was improved, and the peak heat release rate decreased significantly after introducing the well-characterized Ni@SiO2-PA. The absorbance intensity of the toxic aromatic compounds also decreased. Moreover, the char yield of the EP composites was improved because of the synergetic coupled effects between the nickel phytate supermolecules and SiO2 nanotemplates. The possible fire-retardancy mechanism was hypothesized as follows. The crosslinking structure of the silica initially enabled the formation of a polymer network to prevent further decomposition. The N-P synergistic flame-retardancy system then generated a gas barrier and P-rich intumescent char. Besides, char-residue generation was catalyzed by introducing Ni2+, which isolated the heat and the exchange between oxygen and the matrix. Overall, this study proposes a novel green flame retardant that may enable significant improvements in preparing environmentally friendly organic-inorganic materials with applications in the fields of flame-retardant composites.

10.
RSC Adv ; 10(24): 13949-13959, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35498486

RESUMO

A novel functionalized graphene oxide (FGO) wrapped with Si-N-containing flame retardant (FR-fGO) was successfully synthesized via a chemical modification process and applied to enhance the thermal stability, fire resistance, and mechanical properties of epoxy resin (EP). Herein, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to explore the structure and morphology of FR-fGO to overcome the fact that the FGO cannot strongly bond with the polymer matrix. With the incorporation of FR-fGO into EP, the thermal stability improved and the total heat release decreased compared with pure EP. Meanwhile, FR-fGO composites significantly reduced the amount of flammable and toxic volatiles. A possible flame-retardant mechanism of FR-fGO was deduced from a theoretical analysis of the chemical bond energy and the experimental results of thermal decomposition: namely, well-dispersed FR-fGO nanosheets constituted a physical barrier, with an Si-N-containing synergy system forming a highly graphitized residual char with an Si-containing cross-linked network. The enhancement in mechanical properties demonstrated that the composites had remarkable compatibility. This study provides a novel modification strategy to improve the dispersion and flame retardance of graphene.

11.
RSC Adv ; 10(41): 24507-24514, 2020 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35516205

RESUMO

Peptide-containing hydrogels have become a research hotspot due to their unique secondary structure and biocompatibility. Herein, we used amino-terminated F127 as a macroinitiator to initiate the ring-opening polymerization of l-lysine(z)-NCA, and the obtained oligo(lysine)-modified F127 (FL) had degrees of polymerization of lysine of 2, 5, and 8. The results showed that the FL hydrogels had reversible temperature-dependent sol-gel transitions, and the introduction of lysine increased the critical gel temperature. In the dilute solution of FL, the micelle size increased and aggregated as the pH increased; the micelle grew into a rod-like shape under alkaline conditions. Scanning electron micrographs showed that the interior of the FL hydrogel had a more complete porous structure. The FL-2 hydrogel loaded with 5-fluorouracil exhibited an approximately linear release trend within 12 h and has good biocompatibility. Therefore, FL hydrogels have potential applications in the field of biomedicine.

12.
Brain Imaging Behav ; 14(5): 1805-1814, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31183773

RESUMO

Aberrant functional connectivity of brain networks has been demonstrated in migraine sufferers. Functional magnetic resonance imaging (fMRI) may illustrate altered connectivity in patients suffering from migraine without aura (MwoA). Here, we applied a seed-based approach based on limbic regions to investigate disrupted functional connectivity between spontaneous migraine attacks. Resting-state fMRI data were obtained from 28 migraine patients without aura and 23 well-matched healthy controls (HC). The functional connectivity of the limbic system was characterized using a seed-based whole-brain correlation method. The resulting functional connectivity measurements were assessed for correlations with other clinical features. Neuropsychological data revealed significantly increased connectivity between the limbic system (bilateral amygdala and right hippocampus) and left middle occipital gyrus (MOG), and a positive correlation was revealed between disease duration and connective intensity of the left amygdala and the ipsilateral MOG. There was decreased functional connectivity between the right amygdala and contralateral orbitofrontal cortex (OFC). In addition, resting-state fMRI showed that, compared to HC, patients without aura had significant functional connectivity consolidation between the bilateral hippocampus and cerebellum, and a negative correlation was detected between scores on the headache impact test (HIT) and connectivity intensity of the right hippocampus and bilateral cerebellum. There was decreased functional connectivity between the left hippocampus and three brain areas, encompassing the bilateral inferior parietal gyri (IPG) and contralateral supplementary motor area (SMA). There were no structural differences between the two groups. Our data suggest that migraine patients have disrupted limbic functional connectivity to pain-related regions of the modulatory and encoding cortices, which are associated with specific clinical characteristics. Disturbances of resting-state functional connectivity may play a key role in neuropathological features, perception and affection of migraine. The current study provides further insights into the complex scenario of migraine mechanisms. .


Assuntos
Sistema Límbico/diagnóstico por imagem , Sistema Límbico/fisiopatologia , Enxaqueca sem Aura/patologia , Enxaqueca sem Aura/fisiopatologia , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Sistema Límbico/patologia , Imageamento por Ressonância Magnética , Masculino , Enxaqueca sem Aura/diagnóstico por imagem
13.
J Headache Pain ; 20(1): 116, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856703

RESUMO

BACKGROUND: Resting-state functional magnetic resonance imaging (fMRI) has confirmed disrupted visual network connectivity in migraine without aura (MwoA). The thalamus plays a pivotal role in a number of pain conditions, including migraine. However, the significance of altered thalamo-visual functional connectivity (FC) in migraine remains unknown. The goal of this study was to explore thalamo-visual FC integrity in patients with MwoA and investigate its clinical significance. METHODS: Resting-state fMRI data were acquired from 33 patients with MwoA and 22 well-matched healthy controls. After identifying the visual network by independent component analysis, we compared neural activation in the visual network and thalamo-visual FC and assessed whether these changes were linked to clinical characteristics. We used voxel-based morphometry to determine whether functional differences were dependent on structural differences. RESULTS: The visual network exhibited significant differences in regions (bilateral cunei, right lingual gyrus and left calcarine sulcus) by inter-group comparison. The patients with MwoA showed significantly increased FC between the left thalami and bilateral cunei and between the right thalamus and the contralateral calcarine sulcus and right cuneus. Furthermore, the neural activation of the left calcarine sulcus was positively correlated with visual analogue scale scores (r = 0.319, p = 0.043), and enhanced FC between the left thalamus and right cuneus in migraine patients was negatively correlated with Generalized Anxiety Disorder scores (r = - 0.617, p = 0.005). CONCLUSION: Our data suggest that migraine distress is exacerbated by aberrant feedback projections to the visual network, playing a crucial role in migraine physiological mechanisms. The current study provides further insights into the complex scenario of migraine mechanisms.


Assuntos
Enxaqueca sem Aura/fisiopatologia , Tálamo/fisiopatologia , Córtex Visual/fisiopatologia , Adulto , Encéfalo/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
14.
Front Neurosci ; 13: 1010, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31607851

RESUMO

PURPOSE: The present study combined fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and functional connectivity (FC) to explore brain functional abnormalities in acute tinnitus patients (AT) with hearing loss. METHODS: We recruited twenty-eight AT patients and 31 healthy controls (HCs) and ran resting-state functional magnetic resonance imaging (fMRI) scans. fALFF, ReHo, and FC were conducted and compared between AT patients and HCs. After that, we calculated correlation analyses among abnormal fALFF, ReHo, FC, and clinical data in AT patients. RESULTS: Compared with HCs, AT showed increased fALFF values in the right inferior temporal gyrus (ITG). In contrast, significantly decreased ReHo values were observed in the cerebellar vermis, the right calcarine cortex, the right precuneus, the right supramarginal gyrus (SMG), and the right middle frontal gyrus (MFG). Based on the differences in the fALFF and ReHo maps, the latter of which we defined as region-of-interest (ROI) for FC analysis, the right ITG exhibited increased connectivity with the right precentral gyrus. In addition, the right MFG demonstrated decreased connectivity with both the bilateral anterior cingulate cortex (ACC) and the left precentral gyrus. CONCLUSION: By combining ReHo, fALFF, and FC analyses, our work indicated that AT with hearing loss had abnormal intraregional neural activity and disrupted connectivity in several brain regions which mainly involving the non-auditory area, and these regions are major components of default mode network (DMN), attention network, visual network, and executive control network. These findings will help us enhance the understanding of the neuroimaging mechanism in tinnitus populations. Moreover, these abnormalities remind us that we should focus on the early stages of this hearing disease.

15.
Mater Sci Eng C Mater Biol Appl ; 104: 109930, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500069

RESUMO

An injectable hydrogel dressing with multifunctional properties of superior hemostasis, antibacterial activity, tissue adhesive and cytocompatibility is desirable candidate in wound healing. In this study, we developed a novel hydrogel dressing composed of hydrophobically modified chitosan (hmCS) and oxidized dextran (OD). The gelation time, microstructure, injectability, self-healing and rheological properties were characterized. The in vitro ability of the precursor solution of the hydrogels to coagulate heparinized whole blood was confirmed. The in vivo hemostatic activity was demonstrated in a rat hemorrhaging liver model. The antibacterial activity against S. aureus and P. aeruginosa was evaluated in vitro through surface antibacterial test. The corresponding killing efficiencies were up to 95.0% and 96.4% at bacterial concentration of 108 CFU/mL. The cytotoxicity was examined by co-culturing with 3 T3 fibroblast cells. The wound healing functions were further verified with an infected wound model of rat skin. The aforementioned findings demonstrated that the hydrogel with multifunctional activities has potential for hemorrhagic and infected wound healing.


Assuntos
Quitosana/farmacologia , Dextranos/farmacologia , Hidrogéis/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Injeções , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Hemostasia/efeitos dos fármacos , Hidrogéis/química , Masculino , Camundongos , Células NIH 3T3 , Oxirredução , Espectroscopia de Prótons por Ressonância Magnética , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos Sprague-Dawley , Reologia , Staphylococcus aureus/efeitos dos fármacos , Adesivos Teciduais/farmacologia
16.
Sci Rep ; 9(1): 1601, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733516

RESUMO

The hygroexpansion and anisotropy of wood limit its application in construction and wood products industry. Zinc chloride-silicone oil was use to decrease the hygroscopicity and improve the dimensional stability of wood at 80 °C, 140 °C, 160 °C and 180 °C. The effects of the treatment on the dimensional stability, chemical structure, thermal degradation, morphology of wood were evaluated, and the mechanism was determined. Results indicated that the zinc chloride-silicone oil treatment at 80 °C improved the dimensional stability and decreased the hygroscopicity of wood. The tangential, radial, and volumetric swelling coefficients of the treated wood decreased by 9.7%, 33.5%, and 18.2%, respectively, relative to those of the untreated wood. Zinc chloride-silicone oil treatment also changed the chemical structure of wood by degrading the wood components and decreasing the moisture absorption groups. Moreover, zinc chloride-silicone oil treatment significantly influenced the thermal degradation of wood, as samples treated with zinc chloride-silicone oil at 140 °C, 160 °C and 180 °C presented sharp peaks around 511 °C, 501 °C and 473 °C. The control group exhibited a more common derivative thermogravimetric curve with a sharp peak at 375 °C. In addition, the silicone oil could impregnate wood, occlude moisture passage, and prevent the movement of moisture in wood. This method can be applied in building and wood industries to expand the applications of wood products.

17.
ACS Appl Bio Mater ; 2(1): 527-532, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35016316

RESUMO

Pluronic F127 is a thermosensitive polymer that has been extensively studied and utilized in biomedicine. To improve the gelation properties of F127, α-cyclodextrin was introduced by physical interactions, such as forming inclusion complexes, hydrogen bond self-assembly, and hydrophobic interactions, to prepare F127-α-CD hydrogels. This study explored the temperature-dependent sol-gel transition behavior, gelation mechanism, interior morphology, and controlled release of the anticancer drug 5-fluorouracil. Results showed that hydrogel could be obtained at 1.0%-8.0% weight content of F127. The cross-linking points in this system were PEO-α-CD microcrystalline region and micelle with poly(propylene oxide) as the core. The network inside F127-α-CD hydrogels made it stable and conducive for controlled release. Therefore, this hydrogel is a promising drug release system.

18.
ACS Biomater Sci Eng ; 5(5): 2610-2620, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33405766

RESUMO

A multifunctional hydrogel patch with a combination of high toughness, superior adhesion, and good antibacterial effect is a highly desired surgical material. In this study, we developed a novel hydrogel patch composed of poly(ethylene glycol) diacrylate/quaternized chitosan/tannic acid (PEGDA/QCS/TA) based on mussel-inspired chemistry. The physical and biological properties of the hydrogel patch were systematically evaluated in vitro and in vivo. The results indicated that this hydrogel patch possessed compact microstructure, low swelling ratio, tough mechanical properties, good antibacterial activities against S. aureus and E. coli, and excellent dry/wet adhesive ability to a wide range of substrates. The hydrogel patch could also be degraded and absorbed in vivo and used as a sutureless material for wound closure. All these findings demonstrate that the PEGDA/QCS/TA hydrogel patch with multifunctional properties has great potential for application in biomedical fields.

19.
Ultrason Sonochem ; 50: 200-207, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30245204

RESUMO

This work investigated the physicochemical properties of Chinese fir after ultrasound-assisted pretreatments with borax and sodium hydroxide additives in an aqueous solution. TGA, FTIR, and XRD were used to analyze the thermal degradation processes, changes in chemical structures, and crystallinity of the treated samples, respectively. Additionally, the release of volatiles from wood pyrolysis was measured on-line by the TG-FTIR apparatus. In thermal analysis, all samples showed main degradation stages at 220-500 °C, and alkaline compounds could efficiently shift the process to lower temperatures with lower maximum weight loss rate (MWLR) and more residues. From TG-FTIR, it was observed that CO2 was the primary gas product from pyrolysis in the alkaline-treated samples, while there were more carbonyl compounds released in the control and deionized water groups. Due to the destruction and removal of hemicellulose and lignin after alkaline treatments, the related peaks changed greatly. Changes in the ester groups caused by saponification also accounted for one of the most significant differences between samples. Moreover, except for the deionized water group without sonication, the crystallinity of the samples increased from 6.34% to 11.29%. Overall, comparing the samples treated with or without ultrasound, the results showed that the ultrasound treatment did influence the samples' physicochemical properties, and its' effects varied by the basicity of the solution. This in-depth investigation offers a better understanding of ultrasound-assisted and alkaline pretreatments of wood materials.


Assuntos
Abies/química , Boratos/química , Hidróxido de Sódio/química , Ondas Ultrassônicas , China , Cristalização , Cristalografia por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
20.
J Magn Reson Imaging ; 47(5): 1251-1259, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28940646

RESUMO

BACKGROUND: Because chronic kidney disease (CKD) is a worldwide problem, accurate pathological and functional evaluation is required for planning treatment and follow-up. Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) can assess both capillary perfusion and tissue diffusion and may be helpful in evaluating renal function and pathology. PURPOSE: To evaluate functional and pathological alterations in CKD by applying IVIM-DWI. STUDY TYPE: Prospective study. SUBJECTS: In all, 72 CKD patients who required renal biopsy and 20 healthy volunteers. FIELD STRENGTH: 1.5T. ASSESSMENT: All subjects underwent IVIM-DWI of the kidneys, and image analysis was performed by two radiologists. The mean values of true diffusion coefficient (D), pseudo diffusion coefficient (D*), and perfusion fraction (f) were acquired from renal parenchyma. Correlation between IVIM-DWI parameters and estimated glomerular filtration rate (eGFR), as well as pathological damage, were assessed. STATISTICAL TESTS: One-way analysis of variance (ANOVA), paired sample t-test and Spearman correlation analysis. RESULTS: The paired sample t-test revealed that IVIM-DWI parameters were significantly lower in medulla than cortex for both patients and controls (P < 0.01). Regardless of whether eGFR was reduced, ANOVA revealed that f values of renal parenchyma were significantly lower in patients than controls (P < 0.05). Spearman correlation analysis revealed that there were positive correlations between eGFR and D (cortex, r = 0.466, P < 0.001; medulla, r = 0.491, P < 0.001), and between eGFR and f (cortex, r = 0.713, P < 0.001; medulla, r = 0.512, P < 0.001). Negative correlations were found between f and glomerular injury (cortex, r = -0.773, P < 0.001; medulla, r = -0.629, P < 0.001), and between f and tubulointerstitial lesion (cortex, r = -0.728, P < 0.001; medulla, r = -0.547, P < 0.001). DATA CONCLUSION: IVIM-DWI might be feasible for noninvasive evaluation of renal function and pathology of CKD, especially in detection of renal insufficiency at an early stage. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1251-1259.


Assuntos
Capilares/patologia , Imagem de Difusão por Ressonância Magnética , Processamento de Imagem Assistida por Computador/métodos , Rim/diagnóstico por imagem , Perfusão , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/patologia , Adolescente , Adulto , Idoso , Biópsia , Feminino , Taxa de Filtração Glomerular , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Estudos Prospectivos , Insuficiência Renal/diagnóstico por imagem , Adulto Jovem
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