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1.
Poult Sci ; 103(4): 103525, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38394866

RESUMO

The present study was conducted 1) to investigate the effects of gender and temperature on growth performance in broiler chickens and 2) to establish body protein and fat deposition curves and amino acid patterns for broilers of both genders at different ambient temperatures. A total of 432 1-day-old (d) Arbor Acres chickens with a male/female ratio of 1:1 were randomly divided into the following 4 treatment groups: the male thermoneutral group, the female thermoneutral group, the male heat stress group, and the female heat stress group. The chickens in the thermoneutral groups were kept at a comfortable temperature from 1 to 42 d, while chickens in the heat stress groups were kept at a comfortable temperature from 1 to 28 d and at a high ambient temperature from d 29 to 42. The body composition retention data were obtained by comparative slaughter method, and the models were constructed by the Gompertz model. The results revealed significant variation in body protein content (BPC) and body fat deposition efficiency (BFE) between both genders and the 2 temperatures. Moreover, a noteworthy interaction between gender and temperature was observed in terms of the BPC and protein deposition efficiency (BPE). The following equations for body protein and body fat deposition in the thermoneutral groups were obtained: Body protein weight of male broilers: [Formula: see text] ; Body protein weight of female broilers: [Formula: see text] ; Body fat weight of male broilers: [Formula: see text] ; Body fat weight of female broilers: [Formula: see text] . Where t means age (d). The following equations for body protein and body fat deposition in the heat stress groups were obtained: Body protein weight of male broilers: [Formula: see text] ; Body protein weight of female broilers: [Formula: see text] ; Body fat weight of male broilers: [Formula: see text] ; Body fat weight of female broilers: [Formula: see text] . Where t means age (d). In addition, no significant difference in amino acid content was found between different genders and temperatures. The amino acid pattern could be divided into 2 stages: 0 to 14 d and 15 to 42 d. Our equations and patterns enable a deeper understanding of the nutritional requirements in broiler chickens under various temperature conditions. This enables researchers to develop more accurate feeding programs to fulfill the growth and health requirements of broiler chickens.


Assuntos
Galinhas , Transtornos de Estresse por Calor , Feminino , Animais , Masculino , Temperatura , Proteínas/metabolismo , Tecido Adiposo/metabolismo , Aminoácidos/metabolismo , Transtornos de Estresse por Calor/veterinária , Temperatura Alta , Suplementos Nutricionais/análise
2.
Food Chem ; 442: 138494, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38266413

RESUMO

Climacteric bananas are susceptible to endogenous ethylene and temperature, resulting in dehydration, accelerated senescence and deterioration. The widely-used plastic cling films is particularly complicated due to their high consumption and non-degradability. Herein, this study proposed to fabricate a carboxymethyl cellulose/polyvinyl alcohol/pyrazoic acid (CPP) hydrogel for postharvest banana preservation. The hydrogel demonstrated excellent potential as a packaging film, including natural degradability (complete degradation within 50 days), high tensile performance, transparent visibility and biosafety. As a validation experiment, bananas in a 30 °C environment confirmed the effectiveness of CPP hydrogels in banana postharvest preservation. Compared with the blank control and CP hydrogel, CPP packaging film delayed the processes of browning, dehydration, softening, nutrients loss, ripening and senescence in bananas, thereby maintaining their commercial value. Accordingly, this study demonstrates the potential of hydrogel materials as an alternative strategy to climacteric fruit preservation and plastic film.


Assuntos
Climatério , Musa , Musa/metabolismo , Hidrogéis/metabolismo , Desidratação , Embalagem de Produtos , Embalagem de Alimentos
3.
Int J Biol Macromol ; 254(Pt 3): 127950, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37951431

RESUMO

Chitosan has great potential for biomedical applications. However, the intractable solubility of chitosan is a major bottleneck hampering its utilization. In this work, we report a low-temperature solvent-exchange method to solubilize chitosan in biologically relevant solvents (bio-solvents) including water, salines, and cell culture media. Chitosan was firstly dissolved in ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate (EMIM Ac). The chitosan/IL solution was then dialyzed against bio-solvents at 4 °C, during which a solvent exchange process took place. At the end of 24 h dialysis, aqueous chitosan pseudosolutions formed. Low temperature is found to be crucial for efficient solubilization of chitosan during the solvent exchange process. Increasing temperature to 50 °C leads to the formation of solid chitosan hydrogel. Chitosan in the water-based pseudosolution presents as positively charged particles. The pseudosolution shows a high positive zeta potential of about +52.6 mV and good colloidal stability. The water-based pseudosolutions with different amounts of chitosan contents exhibit the rheological features of weak liquid gels. By using these pseudosolutions, the fabrication of various chitosan materials is realized readily. Both chitosan pseudosolution and its downstream products are highly biocompatible. In this strategy, using IL as a solvent-medium and processing a low-temperature solvent exchange are the two key parameters to solubilize chitosan.


Assuntos
Quitosana , Líquidos Iônicos , Solventes , Materiais Biocompatíveis , Temperatura , Diálise Renal , Água
4.
ACS Appl Bio Mater ; 6(9): 3863-3874, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37648658

RESUMO

Pentavalent vanadium [V(V)] has been studied as bioactive ions to improve the bone defect repair; however, its osteogenic promotion mechanism is still not fully understood so far. In this study, a V-doped mesoporous bioactive glass (V-MBG) was prepared, and its effects on osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and potential signaling pathways were investigated. The physicochemical characterization revealed that the incorporation of V slightly reduced the specific surface area and increased the mesoporous pore size, and the abundant mesopores of V-MBG were beneficial to the sustained dissolution of V(V) ions as well as calcium, silicon, and phosphorus ions. Cell proliferation results indicated that the high dilution ratio (>16) V-MBG extract markedly promoted the proliferation of rBMSCs compared with the control group and the same dilution ratio MBG extract. Compared with the same dilution ratio MBG extract, diluted V-MBG extracts markedly promoted the secretion of alkaline phosphatase (ALP) and osteocalcin (OCN) protein at day 7 but insignificantly stimulated the runt-related transcription factor 2 (RUNX2) and vascular endothelial growth factor (VEGF) protein synthesis. In depth, the diluted V-MBG extracts remarkably up-regulated the expression of WNT/ß-catenin pathway direct target genes, including WNT3a, ß-catenin, and AXIN2 genes in contrast to the same dilution ratio MBG extracts, suggesting that the released V(V) ions might promote osteogenic differentiation of rBMSCs via the WNT/ß-catenin signaling pathway.


Assuntos
Células-Tronco Mesenquimais , Via de Sinalização Wnt , Animais , Ratos , Osteogênese , Vanádio , Fator A de Crescimento do Endotélio Vascular , beta Catenina , Diferenciação Celular
5.
ACS Omega ; 8(28): 25288-25294, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37483214

RESUMO

Cytidine is an important kind of nucleoside that can be applied to drug development and food industry. Cytidine sulfate is one of its popular forms, which is promising as a medicinal intermediate, especially in antiviral and antitumor drugs. Product refining is the key point of industrial development, and crystallization is a significant way of refining. In this work, the solubility of cytidine sulfate in pure water from 278.15 to 328.15 K and in water-ethanol binary solvents at 298.15 K was measured by the UV spectroscopic method. The solubility data were correlated with temperature and solvent composition using the modified Apelblat, van't Hoff, and CNIBS/R-K equations. On this basis, we investigated and compared three crystallization processes, and the coupling method was developed to prepare crystals with a large particle size, concentrated distribution, and high yield and packing density. In addition, the structure and stability of the products were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption analysis. It was found that cytidine sulfate has only one crystal form in our research process, and the product of coupling crystallization is stable and favorable for industrial development.

6.
Plant Methods ; 19(1): 50, 2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37231431

RESUMO

Passion fruit is an essential commercial plant in the tropics and subtropics, which has lately seen a rise in demand for high-quality fruits and large-scale production. Generally, different species of passion fruit (Passiflora sp.) are propagated by sexual reproduction. However, asexual reproduction, such as stem cuttings, grafting, or tissue culture, is also available and advantageous in many instances. Recent research on passion fruit has concentrated on improving and establishing methodologies for embryogenesis, clonal proliferation via (somatic embryos), homozygote regeneration (by anther culture), germplasm preservation (via cryopreservation), and genetic transformation. These developments have resulted in potentially new directions for asexual propagation. Even though effective embryo culture and cryogenics are now available, however the limited frequency of embryogenic callus transformation to ex-vitro seedlings still restricts the substantial clonal replication of passion fruit. Here, in this review the advancement related to biotechnological approaches and the current understanding of Passiflora tissue culture. In vitro culture, organogenesis, cryopreservation, breeding, and productivity of Passiflora will significantly improve with novel propagation approaches, which could be applied to a wider range of germplasm.

7.
Artigo em Inglês | MEDLINE | ID: mdl-36673941

RESUMO

The spatial distribution of urban green spaces (UGS) is closely related to the health of residents and the ecological pattern of cities. Exploring the equity of UGSs plays an important role in urban planning and also provides guidance for urban development. Taking the main urban area of Fuzhou City as an example, this study uses network big data and census data to pinpoint the population demand, evaluates the accessibility and equity of UGS within the basic living circle, neighborhood living circle and daily living circle of residents at the scale of residential and sub-districts. Based on the G2SFCA model, we also quantify the actual effective UGS's service capacity. Then, using the scale and travel range as the entry point, we further discuss the similarities and differences under different scales and different travel ranges. Finally, optimization strategies are proposed for the construction status. The results show that: (1) The spatial allocation of urban green space resources varies significantly, and there is a serious inequity in the spatial distribution of urban green space under pedestrian conditions; (2) The results of UGS accessibility, equity, and service capacity in Fuzhou at both residential and sub-district scales are consistent; (3) Urban construction should be multi-level overall planning, combined with local economic and social development factors in accordance with local conditions to take measures. The results of the study can provide a scientific reference for the optimization of the spatial distribution of UGS.


Assuntos
Parques Recreativos , Caminhada , Cidades , China , Viagem
8.
Biotechnol Appl Biochem ; 70(1): 164-174, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35307889

RESUMO

This study aimed to explore the structure and antibacterial properties of chitooligosaccharide monomers with different polymerization degrees and to provide a theoretical basis for inhibiting Salmonella infection. Chitosan was used as a raw material to prepare and separate low-molecular-weight chitooligosaccharides. Chitobiose, chitotriose, and chitotetraose were obtained by gradient elution with cation exchange resin. The molecular weights and acetyl groups of the three monomers were determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and nuclear magnetic resonance (NMR), respectively. Three chitooligosaccharide monomers were used to explore the antibacterial effect on Salmonella. The results showed that the degree of deacetylation of chitosan was 92.6%, and the enzyme activity of chitosanase was 102.53 U/g. Within 18 h, chitosan was enzymatically hydrolyzed to chitooligosaccharides containing chitobiose, chitotriose, and chitotetraose, which were analyzed by thin-layer chromatography (TLC) and MALDI-TOF. MALD-TOF and TLC showed that the separation of monomers with ion exchange resins was effective, and NMR showed that there was no acetyl group. Chitobiose had a poor inhibitory effect on Salmonella, and chitotriose and chitotetraose had equivalent antibacterial effects.


Assuntos
Braquiúros , Quitosana , Animais , Quitosana/farmacologia , Quitosana/química , Hidrólise , Polimerização , Quitina , Oligossacarídeos/farmacologia , Oligossacarídeos/química , Glicosídeo Hidrolases/química , Antibacterianos/farmacologia
9.
Sci Total Environ ; 859(Pt 1): 160173, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36400303

RESUMO

Mangrove is an important carbon sink, as it can achieve climate regulation by sequestering carbon dioxide in the atmosphere. However, 50 % of mangrove species are threatened with extinction in China, and the carbon stocks in vegetation has also dropped by 53.1 %. Here, we couple remote sensing data with Random Forests, Support Vector Machines, and XGBoost to analyse mangroves in mainland China from 1986 to 2019. We find that aquaculture has crucial impacts on mangroves and prediction error. Future predictions indicate that the changes of mangroves in different cities range from -5.09E+06 m2 to 2.30E+06 m2, and soil carbon(C) stocks is "-1.90E+05 Mg ~ 8.57E+04 Mg". To protect mangroves, exploring the balance between aquaculture and mangroves and paying attention to the sustainable transformation of aquaculture are urgently required. In this way, mangroves can fully play the role of carbon sequestration and contribute to China's dual carbon goals.


Assuntos
Solo , Áreas Alagadas , Sequestro de Carbono , Aquicultura , Aprendizado de Máquina , China , Ecossistema
10.
Stem Cells Dev ; 32(1-2): 1-11, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36453239

RESUMO

Previous studies showed that acellular nerve allografts (ANAs) have been successfully utilized in repairing peripheral nerve defects, and exosomes produced by stem cells are useful in supporting axon regrowth after peripheral nerve injury. In this study, exosomes from hair follicle epidermal neural crest stem cells (EPI-NCSCs-Exos) combined with ANAs were used to bridge facial nerve defects. EPI-NCSCs-Exos were isolated by ultracentrifuge, and were identified. After coculture, EPI-NCSCs-Exos were internalized into dorsal root ganglions (DRGs) and schwann cells (SCs) in vitro, respectively. EPI-NCSCs-Exos elongate the length of axons and dendrites of DRGs, and accelerated the proliferation and migration of SCs, and increased neurotrophic factor expression of SCs as well. The next step was to assign 24 Sprague Dawley male rats randomly and equally into three groups: the autograft group, the ANA group, and the ANA + EPI-NCSCs-Exos group. Each rat manufactured a 5-mm gap of facial nerve defect and immediately bridged by the corresponding transplants, respectively. After surgery, behavioral changes and electrophysiological testing of each rat were observed and assessed. At 90 days postoperatively, the retrogradely fluorescent tracer-labeled neurons were successfully observed on the injured side in the three groups. Morphological changes of facial nerve regeneration were evaluated by transmission electron microscopy and semithin toluidine blue staining. The results showed that nerve fiber density, nerve fiber diameter, and myelin sheath thickness in the ANA group were significantly worse than those in the other two groups (P < 0.05). No significant difference in nerve fiber density and myelin sheath thickness was observed between the autograft group and the ANA + EPI-NCSCs-Exos group (P = 0.14; P = 0.23). Our data indicated that EPI-NCSCs-Exos facilitate ANAs to bridge facial nerve defects and have the potential to replace autograft therapy in clinic.


Assuntos
Exossomos , Nervo Facial , Animais , Masculino , Ratos , Aloenxertos , Folículo Piloso , Regeneração Nervosa/fisiologia , Crista Neural , Ratos Sprague-Dawley , Nervo Isquiático/lesões , Células-Tronco
11.
J Biomater Sci Polym Ed ; 34(7): 845-859, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36346014

RESUMO

The present work is intended to provide a base for further investigation of the composite scaffolds for bone tissue engineering, and whitlockite/polyurethane (WH/PU) scaffolds, in particular. WH Ca18Mg2(HPO4)2(PO4)12 was successfully prepared by means of a chemical reaction between Ca(OH)2, Mg(OH)2 and H3PO4. WH/PU scaffolds were synthesized via in situ polymerization. Synthesized WH particles and WH/PU composite scaffolds were characterized using FTIR, XRD, SEM and EDS. The porosity of scaffolds was calculated by the liquid displacement method. The water contact angle of scaffolds was tested. Mechanical characterization of WH/PU composite scaffolds was evaluated according to monotonic and cyclic compression examination. MC3T3-E1 cells were employed to evaluate the cytocompatibility of scaffolds. The results showed that WH and PU were completely integrated into composite biomaterials. The maximum compressive strength and elastic modulus of WH/PU composite scaffold reached up to 5.2 and 14.1 MPa, respectively. WH/PU composite scaffold had maximum 73% porosity. The minimum contact angle of WH/PU composite scaffold was 89.16°. WH/PU composite scaffolds have a good elasticity. Cyclic compression tests showed that scaffold could recover 90% of its original shape 1 h after removing the load. WH/PU composite scaffolds exhibited a high affinity to MC3T3-E1 cells. WH/PU composite scaffolds significantly promoted proliferation and alkaline phosphatase activity of MC3T3-E1 cells when compared to those grown on tissue culture well plates. It is suggested that the WH/PU scaffolds might be suitable for the application of bone tissue engineering.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Engenharia Tecidual/métodos , Tecidos Suporte/química , Porosidade , Poliuretanos/química , Durapatita/química , Materiais Biocompatíveis/química
12.
J Ethnopharmacol ; 302(Pt A): 115914, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36347303

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: As one of the important traditional Chinese medicines, Alpinia oxyphylla could warm and tonify the kidney and spleen. It has been used as anti-salivation, anti-diarrhea in various diseases. In recent years, many studies have reported the significant effect of Alpinia oxyphylla on improving cognitive ability, anti oxidative stress and protecting neurons. AIMS OF THE STUDY: In this paper, we studied whether AE and its main active components could improve M1 and M2 polarization, inhibit neuroinflammation through triggering receptor expressed on myeloid cells 2 (TREM2), and exert anti-inflammatory effects. MATERIALS AND METHODS: In this paper, the concentrations of inflammatory cytokines such as NO, TNF-α, IL-10 were assessed using detection kits respectively. Arg-1 and Iba-1, as polarized markers of M1 and M2, were detected by Immunofluorescence staining. CD86 and CD206 were tested by flow cytometry as surface markers of M1 and M2. Furthermore, RT-PCR was performed to determinate TNF-α, IL-10, Arg-1, and Iba-1. Western blot was used to test the activation of PI3K/AKT/GSK3ß and BDNF/TrkB/TLR4 signaling pathways. TREM2 siRNA treatment further verified the action target of Chrysin, the main active ingredient of Alpinia oxyphylla. Molecular docking study was performed to investigate the binding mode between Chrysin and the human TREM2. RESULTS: We found that AE could promote the phenotypic transformation of microglia from M1 to M2, and similar effects of Chrysin were observed. Furthermore, downregulation of TREM2 blocked the anti-neuroinflammation of Chrysin, and inhibited the shift of M1 phenotype to M2 phenotype. Additionally, TREM2-siRNA suppressed the effects of Chrysin on PI3K/AKT/GSK3ß and BDNF/TrkB/TLR4 signaling pathways. CONCLUSIONS: Our findings indicated that AE could improve the polarization response of microglia. TREM2 plays a vital role in the microglial repolarization effects of Chrysin through PI3K/AKT/GSK3ß and BDNF/TrkB/TLR4 signaling pathways regulated by neuroinflammation.


Assuntos
Lipopolissacarídeos , Microglia , Humanos , Lipopolissacarídeos/farmacologia , Interleucina-10/metabolismo , Receptor 4 Toll-Like/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , RNA Interferente Pequeno/farmacologia , Simulação de Acoplamento Molecular , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo
13.
Sensors (Basel) ; 22(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36560024

RESUMO

An MHD vibration sensor, as a new type of sensor used for vibration measurements, meets the technical requirements for the low-noisy measurement of acceleration, velocity, and micro-vibration in spacecraft during their development, launch, and orbit operations. A linear vibration sensor with a runway type based on MHD was independently developed by a laboratory. In a practical test, its output signal was mixed with a large amount of noise, in which the continuous narrowband interference was particularly prominent, resulting in the inability to efficiently carry out the real-time detection of micro-vibration. Considering the high interference of narrowband noise in linear vibration signals, a single-channel blind signal separation method based on SSA and FastICA is proposed in this study, which provides a new strategy for linear vibration signals. Firstly, the singular spectrum of the linear vibration signal with noise was analyzed to suppress the narrowband interference in the collected signal. Then, a FastICA algorithm was used to separate the independent signal source. The experimental results show that the proposed method can effectively separate the useful linear vibration signals from the collected signals with low SNR, which is suitable for the separation of the MHD linear vibration sensor and other vibration measurement sensors. Compared with EEMD, VMD, and wavelet threshold denoising, the SNR of the separated signal is increased by 10 times on average. Through the verification of the actual acquisition of the linear vibration signal, this method has a good denoising effect.

14.
J Agric Food Chem ; 70(29): 9132-9142, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35849541

RESUMO

The objective of this study was to investigate the effect of starch debranching followed by differential ethanol precipitation on the formation and in vitro fermentation of starch-lipid complexes. Three groups of linear glucan chains, with a degree of polymerization (DP) of 383∼2950, 37∼75, and 3∼8, were obtained after debranched maize starch (DMS) was fractionated by differential ethanol precipitation. The glucan fraction with DP 383∼2950 formed only type IIb complexes with lauric acid (LA), whereas the fraction with DP 37∼75 formed predominantly type Ia complexes. The glucan faction with DP 8∼32 did not form V-complexes with LA. In vitro fermentation of the type IIb complexes with human fecal samples promoted the proliferation of butyrate-producing bacteria Megamonas, Blautia, and Megasphaera and resulted in a larger amount of butyrate and total short-chain fatty acids being produced than in similar fermentations of the maize starch-LA complex, DMS-LA complex, and fructo-oligosaccharides. This study showed that starch-lipid complexes with a more stable type IIb crystallite resulted in a greater production of butyrate.


Assuntos
Etanol , Zea mays , Amilose , Butiratos , Ácidos Graxos Voláteis , Fermentação , Glucanos , Humanos , Amido/metabolismo , Zea mays/metabolismo
15.
Rev Sci Instrum ; 93(3): 033002, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35364987

RESUMO

The production and consumption of austenitic stainless steel account for about 70% of stainless steel worldwide. The content of chromium (Cr) must be accurately detected and controlled to form a stable austenite structure and obtain strong properties in production. Laser-induced breakdown spectroscopy (LIBS) can be used to detect the Cr content of austenitic stainless steel in a complex production process. However, LIBS signals may be weak and unstable because the experimental signals are seriously affected by noise, self-absorption, the matrix effect, and the instability of the shot-to-shot signal, rendering the quantitative detection results inaccurate and unstable. The spectral-preprocessing methods of baseline correction and denoising can improve the accuracy of quantitative detection of LIBS. An improved segmented Hermite cubic-interpolation method is proposed herein to correct the baseline offset and produce baseline signals that are smooth and convergent (to overcome the Runge phenomenon). Empirical mode decomposition (EMD) based on the wavelet method is proposed to remove LIBS noise; this is done by exploiting the adaptivity of EMD to refine the wavelet-scaling coefficients. Compared with other denoising methods, the proposed method has good denoising evaluation indices and stability and, thus, effectively removes the noise. To verify detection accuracy, the internal standard quantitative method is used to detect the Cr content, and a cyclic-inversion prediction method is designed to verify detection stability. The results show that the correlation coefficient of the calibration curve is improved, the root-mean-square error is reduced, and the average relative error of the predicted Cr content decreases from 10.46% to 3.858%.

16.
Colloids Surf B Biointerfaces ; 214: 112482, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35366577

RESUMO

Conductive hydrogels based on MXene have gained more attention due to the excellent conductive property and biocompatibility. At present, they have great potential in electronic skins, personally healthcare monitoring and human motion sensing. However, MXene are prone to be oxidized due to the abundant hydroxyls, which results in the unstable conductive property of hydrogel. To improve the shortcoming, conductive PAA/PAM/MXene/TA hydrogel was prepared, in which the introduction of TA can prevent MXene from oxidation owing to the great deal of pyrogallol groups. Mechanical tests showed that the tensile strength, toughness and elongation at break of PAA/PAM/MXene/TA hydrogel are 0.251 ± 0.05 MPa, 0.895 ± 0.16 MJ/m3 and 560.82 ± 19.56%, respectively, indicating the hydrogel possess good stretchability. In addition, the MXene and TA were introduced into hydrogel through hydrogen bonds, which endow the hydrogel with good restorability and self-healing property. Resistance variation-strain curves demonstrated that the introduction of MXene endue the hydrogel with appreciable sensing performances. Moreover, in vitro cytotoxicity assay indicated that the hydrogel has good biocompatibility. In conclusion, PAA/PAM/MXene/TA hydrogel has great potential in flexible wearable sensor field.


Assuntos
Hidrogéis , Dispositivos Eletrônicos Vestíveis , Antioxidantes/farmacologia , Condutividade Elétrica , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Resistência à Tração
17.
Carbohydr Polym ; 287: 119330, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35422309

RESUMO

Inspired by the initial mineralization process in bone matrix vesicles (MVs), we used Dulbecco's Modified Eagle's Medium (DMEM) to establish the similar physiological environment to that in MVs for biomimetic mineralization on alginate (ALG) microspheres. The results showed that HA crystals were firstly formed and anchored on the membrane of microspheres like the initial deposition of hydroxyapatite crystals inside MVs. With the continuous growth and accumulation of mineral crystals, HA coating was finally formed on ALG microspheres. The mineralized ALG microspheres (M-ALG microspheres) show good biocompatibility and osteogenic performance. The HA coating is also conducive to the active migration of osteoblasts to the surface of M-ALG microspheres. Collectively, bone-like HA crystals anchored on ALG microspheres may provide a good prospect to promote the repair of bone defects.


Assuntos
Alginatos , Durapatita , Alginatos/química , Regeneração Óssea , Osso e Ossos , Durapatita/química , Durapatita/farmacologia , Microesferas
18.
Nanotechnology ; 33(23)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35189608

RESUMO

Background. Layered double hydroxide (LDH) has been demonstrated as a highly efficient antigen platform to induce effective and durable immune response. However, whether LDH nanoparticles could act as an adjuvant for pertussis vaccines is still unknown. Here we evaluated the potential of Mg/Al-LDH as a nano-adjuvant to improve immune response against pertussis and compared it with commercial aluminum hydroxide (AH) adjuvant.Method. The Mg/Al-LDH nanoparticles were synthesized by a hydrothermal reaction. The morphology, structure and size of Mg/Al-LDH were characterized by transmission electron microscope, x-ray diffraction and MALVERN particle analysis. The ovalbumin and Pertussis toxin (PTd) was adsorbed to Mg/Al-LDH. The immune response of antigen-LDH complex was evaluated in mice, compared with commercial adjuvant alum. Hematoxylin-eosin staining was used to evaluate the inflammatory response at injection site.Results. The synthetic Mg/Al-LDH nanoparticles showed a typical hexagonal lamellar structure. The average size of synthetic nanoparticles was 102.9 nm with PDI of 0.13 and zeta potential was 44.4 mV. Mg/Al-LDH nanoparticles effectively adsorbed protein antigen and mediated antigen uptake by DC cells. Animal experiments showed that Mg/Al-LDH gave enhancement in anti-pertussis toxin (PTd) humoral immune response, which was considerable to commercial AH adjuvant. Finally, Mg/Al-LDH produced a slighter inflammatory response than AH at injection site and this injury was quickly recovered.Conclusion. Our study demonstrated the potential of Mg/Al-LDH as an effective adjuvant for pertussis vaccine, which induced comparable antibody response and had a better safety compared with commercial AH adjuvant.


Assuntos
Hidróxido de Alumínio , Nanopartículas , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Alumínio , Hidróxido de Alumínio/química , Animais , Hidróxidos/química , Camundongos , Nanopartículas/química , Vacina contra Coqueluche
19.
Cell Death Dis ; 13(1): 84, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-35082283

RESUMO

Deregulated lncRNAs play critical roles in tumorigenesis and tumor progression. NR2F1-AS1 is an antisense lncRNA of NR2F1. However, the biological function of NR2F1-AS1 in gastric cancer (GC) remains largely unclear. In this study, we revealed that NR2F1-AS1 and NR2F1 were both positively correlated with the degree of malignancy and predicted poor prognosis in two independent GC cohorts. Besides, NR2F1-AS1 and NR2F1 can respond to Epithelial-to-mesenchymal transition (EMT) signaling in GC, since their expression was increased by TGF-beta treatment and decreased after stable overexpression of OVOL2 in GC cell lines. NR2F1-AS1 and NR2F1 were highly co-expressed in pan-tissues and pan-cancers. Depletion of NR2F1-AS1 compromised the expression level of NR2F1 in GC cells. Furthermore, NR2F1-AS1 knockdown inhibited the proliferation, migration, invasion and G1/S transition of GC cells. More importantly, transcriptome sequencing revealed a novel ceRNA network composed of NR2F1-AS1, miR-29a-3p, and VAMP7 in GC. The overexpression of VAMP7 predicted poor prognosis in GC. Rescue assay confirmed that NR2F1-AS1 promotes GC progression through miR-29a-3p/VAMP7 axis. Our finding highlights that the aberrant expression of NR2F1-AS1 is probably due to the abnormal EMT signaling in GC. LncRNA NR2F1-AS1 plays crucial roles in GC progression by modulating miR-29a-3p/VAMP7 axis, suggesting that NR2F1-AS1 may serve as a potential therapeutic target in GC.


Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias Gástricas , Fator I de Transcrição COUP/genética , Fator I de Transcrição COUP/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas R-SNARE/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Neoplasias Gástricas/patologia , Fatores de Transcrição/metabolismo
20.
J Appl Psychol ; 107(10): 1843-1863, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34941290

RESUMO

Whereas the majority of research to date has shown that having employees with empathic concern brings a number of beneficial outcomes to those on the receiving end, we shift this focus from the targets to a focus on how empathic concern influences the actors. Drawing from conservation of resources (COR) theory and the work-home resources model, we examined the detriments and benefits of empathic concern on the actors themselves by investigating how empathic concern drains and supplies actors' volatile personal resources. Using two experience sampling studies, our results revealed that empathic concern is associated with both resource loss and resource gain. Specifically, empathic concern requires actors to expend their volatile personal resources, leaving them emotionally exhausted and further prompting them to psychologically withdrawal from work. In addition, empathic concern also helps employees acquire new volatile personal resources, boosting their self-efficacy, and further promoting their engagement in organizational citizenship behaviors toward individuals. We also found that individuals with lower trait positive affect are less likely to obtain resource gain (self-efficacy) from empathic concern and more likely to result in resource loss (emotional exhaustion). Overall, our research answers the questions of why and when the negative and positive outcomes of empathic concern are likely to occur for the actors themselves. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Empatia , Comportamento Social , Emoções , Humanos
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