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1.
Nat Commun ; 15(1): 5636, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38965232

ABSTRACT

Natural antimicrobial peptides (AMPs) and enzymes (AMEs) are promising non-antibiotic candidates against antimicrobial resistance but suffer from low efficiency and poor stability. Here, we develop peptide nanozymes which mimic the mode of action of AMPs and AMEs through de novo design and peptide assembly. Through modelling a minimal building block of IHIHICI is proposed by combining critical amino acids in AMPs and AMEs and hydrophobic isoleucine to conduct assembly. Experimental validations reveal that IHIHICI assemble into helical ß-sheet nanotubes with acetate modulation and perform phospholipase C-like and peroxidase-like activities with Ni coordination, demonstrating high thermostability and resistance to enzymatic degradation. The assembled nanotubes demonstrate cascade antifungal actions including outer mannan docking, wall disruption, lipid peroxidation and subsequent ferroptotic death, synergistically killing >90% Candida albicans within 10 min on disinfection pad. These findings demonstrate an effective de novo design strategy for developing materials with multi-antimicrobial mode of actions.


Subject(s)
Antifungal Agents , Candida albicans , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Candida albicans/drug effects , Microbial Sensitivity Tests , Nanotubes/chemistry , Antimicrobial Peptides/pharmacology , Antimicrobial Peptides/chemistry , Lipid Peroxidation/drug effects , Peptides/pharmacology , Peptides/chemistry
2.
Nanotechnology ; 35(32)2024 May 20.
Article in English | MEDLINE | ID: mdl-38697049

ABSTRACT

Perovskite quantum dots (QDs) and organic materials have great research potential in the field of optoelectronic devices. In this paper, MEH-PPV/CsPbBr3heterojunction photodetectors (PDs) are prepared by spin coating method based on the good photoelectric properties of CsPbBr3perovskite QDs and MEH-PPV. The MEH-PPV/CsPbBr3heterojunction improves the energy level arrangement, and CsPbBr3QDs can passivate the surface defects of MEH-PPV films to achieve effective charge separation and transfer, thus inhibiting the dark current and improving the photoelectric performance of the device. Under 532 nm laser irradiation, the responsivity (R) of MEH-PPV/CsPbBr3heterojunction PD is 11.98 A W-1, the specific detectivity (D*) is 6.98 × 1011Jones, and the response time is 15/16 ms. This work provides experience for the study of perovskite QDs and organic materials heterojunction optoelectronic devices.

3.
Curr Ther Res Clin Exp ; 100: 100743, 2024.
Article in English | MEDLINE | ID: mdl-38617895

ABSTRACT

Objective: This study aims to analyze a severe adverse reaction of pulmonary fibrosis induced by dronedarone hydrochloride tablets, and to provide a reference for clinical rational medication through drug precautions. Methods: A case of pulmonary fibrosis induced by dronedarone hydrochloride tablets, along with related literature was retrospectively analyzed. Results: Patients over 65 years old with a history of exposure to amiodarone may increase the incidence of pulmonary toxicity induced by dronedarone, and dronedarone should not be selected as a substitute treatment drug for patients with amiodarone-induced pulmonary toxicity. Conclusions: It is recommended that clinicians monitor the diffusion capacity of carbon monoxide and lung ventilation function of patients before and after using dronedarone for treatment. For patients with a history of amiodarone exposure, intermittent monitoring of chest X-rays and lung function is necessary. If lung function decreases, dronedarone should be immediately discontinued.

4.
Small ; : e2309431, 2024 Feb 25.
Article in English | MEDLINE | ID: mdl-38402425

ABSTRACT

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) is a promising gene editing tool to treat diseases at the genetic level. Nonetheless, the challenge of the safe and efficient delivery of CRISPR/Cas9 to host cells constrains its clinical applicability. In the current study, a facile, redox-responsive CRISPR/Cas9-Ribonucleoprotein (RNP) delivery system by combining iron-coordinated aggregation with liposomes (Fe-RNP@L) is reported. The Fe-RNP is formed by the coordination of Fe3+ with amino and carboxyl groups of Cas9, which modifies the lipophilicity and surface charge of RNP and alters cellular uptake from primary endocytosis to endocytosis and cholesterol-dependent membrane fusion. RNP can be rapidly and reversibly released from Fe-RNP in response to glutathione without loss of structural integrity and enzymatic activity. In addition, iron coordination also improves the stability of RNP and substantially mitigates cytotoxicity. This construct enabled highly efficient cytoplasmic/nuclear delivery (≈90%) and gene-editing efficiency (≈70%) even at low concentrations. The high payload content, high editing efficiency, good stability, low immunogenicity, and ease of production and storage, highlight its potential for diverse genome editing and clinical applications.

5.
Adv Sci (Weinh) ; 11(16): e2304940, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38417114

ABSTRACT

Inadequate ß-cell mass and insulin secretion are essential for the development of type 2 diabetes (T2D). TNF-α-induced protein 8-like 1 (Tipe1) plays a crucial role in multiple diseases, however, a specific role in T2D pathogenesis remains largely unexplored. Herein, Tipe1 as a key regulator in T2D, contributing to the maintenance of ß cell homeostasis is identified. The results show that the ß-cell-specific knockout of Tipe1 (termed Ins2-Tipe1BKO) aggravated diabetic phenotypes in db/db mice or in mice with high-fat diet-induced diabetes. Notably, Tipe1 improves ß cell mass and function, a process that depends on Gαs, the α subunit of the G-stimulating protein. Mechanistically, Tipe1 inhibited the K48-linked ubiquitination degradation of Gαs by recruiting the deubiquitinase USP5. Consequently, Gαs or cAMP agonists almost completely restored the dysfunction of ß cells observed in Ins2-Tipe1BKO mice. The findings characterize Tipe1 as a regulator of ß cell function through the Gαs/cAMP pathway, suggesting that Tipe1 may emerge as a novel target for T2D intervention.


Subject(s)
Cell Proliferation , Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , Mice, Knockout , Signal Transduction , Animals , Mice , Insulin-Secreting Cells/metabolism , Signal Transduction/genetics , Cell Proliferation/genetics , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Intracellular Signaling Peptides and Proteins/genetics , Insulin Secretion/genetics , Cyclic AMP/metabolism , Disease Models, Animal , Male , Humans , Mice, Inbred C57BL , Insulin/metabolism , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/genetics
6.
Surgery ; 175(4): 1140-1146, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38290878

ABSTRACT

BACKGROUND: Hand-sewn anastomosis and stapled anastomosis are the 2 main types of gastrojejunal anastomotic methods in pancreaticoduodenectomy. There is ongoing debate regarding the most effective anastomotic method for reducing delayed gastric emptying after pancreaticoduodenectomy. This study aims to identify factors that influence delayed gastric emptying after pancreaticoduodenectomy and assess the impact of different anastomotic methods on delayed gastric emptying. METHODS: The study included 1,077 patients who had undergone either hand-sewn anastomosis (n = 734) or stapled anastomosis (n = 343) during pancreaticoduodenectomy between December 2016 and November 2021 at our department. We retrospectively analyzed the clinical data, and a 1:1 propensity score matching was performed to balance confounding variables. RESULTS: After propensity score matching, 320 patients were included in each group. Compared with the stapled anastomosis group, the hand-sewn anastomosis group had a significantly lower incidence of delayed gastric emptying (28 [8.8%] vs 55 [17.2%], P = .001) and upper gastrointestinal tract bleeding (6 [1.9%] vs 17 [5.3%], P = .02). Additionally, the hand-sewn anastomosis group had a significantly reduced postoperative length of stay and lower hospitalization expenses. However, the hand-sewn anastomosis group had a significantly longer operative time, which was consistent with the analysis before propensity score matching. Logistic regression analysis showed that stapled anastomosis, intra-abdominal infection, and clinically relevant postoperative pancreatic fistula were independent prognostic factors for delayed gastric emptying. CONCLUSION: Hand-sewn anastomosis was associated with a lower incidence rate of clinically relevant delayed gastric emptying after pancreaticoduodenectomy. Stapled anastomosis, intra-abdominal infection, and clinically relevant postoperative pancreatic fistula could increase the incidence of postoperative clinically relevant delayed gastric emptying. Hand-sewn anastomosis should be considered by surgeons to reduce the occurrence of postoperative delayed gastric emptying and improve patient outcomes.


Subject(s)
Gastroparesis , Intraabdominal Infections , Humans , Pancreaticoduodenectomy/adverse effects , Pancreaticoduodenectomy/methods , Retrospective Studies , Gastroparesis/epidemiology , Gastroparesis/etiology , Gastroparesis/prevention & control , Pancreatic Fistula/epidemiology , Pancreatic Fistula/etiology , Pancreatic Fistula/prevention & control , Anastomosis, Surgical/adverse effects , Anastomosis, Surgical/methods , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Intraabdominal Infections/complications , Gastric Emptying , Treatment Outcome
7.
Nat Commun ; 14(1): 5808, 2023 09 19.
Article in English | MEDLINE | ID: mdl-37726302

ABSTRACT

Amyloid-like assembly is not only associated with pathological events, but also leads to the development of novel nanomaterials with unique properties. Herein, using Fmoc diphenylalanine peptide (Fmoc-F-F) as a minimalistic model, we found that histidine can modulate the assembly behavior of Fmoc-F-F and induce enzyme-like catalysis. Specifically, the presence of histidine rearranges the ß structure of Fmoc-F-F to assemble nanofilaments, resulting in the formation of active site to mimic peroxidase-like activity that catalyzes ROS generation. A similar catalytic property is also observed in Aß assembled filaments, which is correlated with the spatial proximity between intermolecular histidine and F-F. Notably, the assembled Aß filaments are able to induce cellular ROS elevation and damage neuron cells, providing an insight into the pathological relationship between Aß aggregation and Alzheimer's disease. These findings highlight the potential of histidine as a modulator in amyloid-like assembly of peptide nanomaterials exerting enzyme-like catalysis.


Subject(s)
Histidine , Nanostructures , Reactive Oxygen Species , Amyloidogenic Proteins , Peptides
8.
Ecotoxicol Environ Saf ; 255: 114796, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36948006

ABSTRACT

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 µg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17ß-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.


Subject(s)
Leydig Cells , Nanoparticles , Mice , Animals , Male , Humans , Leydig Cells/metabolism , Microplastics/metabolism , Polystyrenes/toxicity , Plastics/metabolism , Nanoparticles/toxicity , Nanoparticles/metabolism , Testosterone/metabolism
9.
Anal Chim Acta ; 1250: 340970, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36898811

ABSTRACT

Immobilized enzymes outperform free enzymes in many properties and are widely used in environmental monitoring, engineering applications, food and medical fields. Based on the developed immobilization techniques, the search for immobilization with wider applicability, lower cost and more stable enzyme properties is of significant importance. In this study, we reported a molecular imprinting strategy for immobilizing peptide mimics of DhHP-6 on mesoporous materials. The DhHP-6 molecularly imprinted polymer (MIP) showed much higher adsorption capacity than raw mesoporous silica toward DhHP-6. The DhHP-6 peptide mimics was immobilized on the surface of mesoporous silica for the fast detection of phenolic compounds, a widely spread pollutant with highly toxic and difficult in degradation. Immobilized enzyme of DhHP-6-MIP exhibited higher peroxidase activity, better stability, and recyclability than free peptide. Notably, DhHP-6-MIP showed excellent linearity for the detection of the two phenols with detection limits of 0.28 µM and 0.25 µM, respectively. In combination with the spectral analysis and PCA method, DhHP-6-MIP provided better discrimination between the six phenolic compounds (phenol, catechol, resorcinol, hydroquinone, 2-chlorophenol, 2, 4-dichlorophenol). Our study showed that immobilization of peptide mimics by the molecular imprinting strategy using mesoporous silica as carriers was a simple and effective approach. The DhHP-6-MIP has great potentiality for the monitoring and degradation of environmental pollutants.


Subject(s)
Molecular Imprinting , Nanoparticles , Polymers/chemistry , Phenols/chemistry , Molecular Imprinting/methods , Molecularly Imprinted Polymers , Peptides , Silicon Dioxide/chemistry , Adsorption
10.
Front Endocrinol (Lausanne) ; 14: 1114463, 2023.
Article in English | MEDLINE | ID: mdl-36891048

ABSTRACT

As emerging organic contaminants, per- and polyfluoroalkyl substances (PFASs) have aroused worldwide concern due to their environmental persistence, ubiquitous presence, bioaccumulation, and potential toxicity. It has been demonstrated that PFASs can accumulate in human body and cause multiple adverse health outcomes. Notably, PFASs have been detected in the semen of human, posing a potential hazard to male fecundity. This article reviews the evidence about the toxic effects of exposure to PFASs on male reproduction, focusing on the sperm quality. Epidemiological studies showed that PFASs, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were adversely associated with the semen parameters in humans, including sperm count, morphology and motility. Experimental results also confirmed that PFAS exposure led to testicular and epididymal damage, therefore impairing spermatogenesis and sperm quality. The mechanisms of reproductive toxicity of PFASs may be involved in blood-testosterone barrier destruction, testicular apoptosis, testosterone synthesis disorder, and membrane lipid composition alteration, oxidative stress and Ca2+ influx in sperm. In conclusion, this review highlighted the potential threat of exposure to PFASs to human spermatozoa.


Subject(s)
Environmental Pollutants , Fluorocarbons , Male , Humans , Semen , Environmental Pollutants/toxicity , Fluorocarbons/toxicity , Spermatozoa , Testosterone
11.
Nanotechnology ; 34(22)2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36854175

ABSTRACT

Ga2O3is a good candidate for deep ultraviolet photodetectors due to its wide-bandgap, good chemical, and thermal stability. Ga2O3-based photoelectrochemical (PEC) photodetectors attract increasing attention due to the simple fabrication and self-powered capability, but the corresponding photoresponse is still inferior. In this paper, the oxygen vacancy (Vo) engineering towardsα-Ga2O3was proposed to obtain high-performance PEC photodetectors. Theα-Ga2O3nanorods were synthesized by a simple hydrothermal method with an annealing process. The final samples were named as Ga2O3-400, Ga2O3-500, and Ga2O3-600 for annealing at 400 ℃, 500 ℃, and 600 ℃, respectively. Different annealing temperatures lead to different Voconcentrations in theα-Ga2O3nanorods. The responsivity is 101.5 mA W-1for Ga2O3-400 nanorod film-based PEC photodetectors under 254 nm illumination, which is 1.4 and 4.0 times higher than those of Ga2O3-500 and Ga2O3-600 nanorod film-based PEC photodetectors, respectively. The photoresponse ofα-Ga2O3nanorod film-based PEC photodetectors strongly depends on the Voconcentration and high Voconcentration accelerates the interfacial carrier transfer of Ga2O3-400, enhancing the photoresponse of Ga2O3-400 nanorod film-based PEC photodetectors. Furthermore, theα-Ga2O3nanorod film-based PEC photodetectors have good multicycle, long-term stability, and repeatability. Our result shows thatα-Ga2O3nanorods have promising applications in deep UV photodetectors.

12.
RSC Adv ; 12(51): 32898-32902, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36425211

ABSTRACT

Nanozyme is a material with enzyme-like catalytic activity, which has been widely used in environmental, antibacterial, and other fields of research. However, there are few reports on the toxicity of nanozymes. In this work, nanozymes co-assembled from sodium N-lauroyl sarcosinate (Ls) and Cu ions possess a Cu(i)-Cu(ii) electron transfer system similar to that of natural laccases. Reaction kinetic studies show that the catalyst follows a typical Michaelis-Menten model. Cu-N-lauroyl sarcosinate nanozyme (Cu-Ls NZ) possess excellent laccase-like activity to oxidize a variety of phenol-containing substrates, such as phenol, 4-iodophenol, and 2,4,5-trichlorophenol. To evaluate the toxicity of the material, the nematode C. elegans was exposed to various concentrations of Cu-Ls NZ. Effects on physiological levels were determined. The results showed that high doses of Cu-Ls NZ increased the amount of reactive oxygen species (ROS), decreased the locomotor activity of nematodes, and inhibited their larval growth.

13.
Small Methods ; 6(11): e2200740, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36180397

ABSTRACT

Due to their accessible lattice oxygen redox (l-OR) at high voltages, Li-rich layered transition metal (TM) oxides have shown promising potential as candidate cathodes for high-energy-density Li-ion batteries. However, this l-OR process is also associated with unusual electrochemical issues such as voltage hysteresis and long-term voltage decay. The structure response mechanism to the l-OR behavior also remains unclear, hindering rational structure optimizations that would enable practical Li-rich cathodes. Here, this study reveals a strong coupling between l-OR and structure dynamic evolutions, as well as their effects on the electrochemical properties. Using the technique of neutron total scattering with pair distribution function analysis and small-angle neutron scattering, this study quantifies the local TM migration and formation of nanopores that accompany the l-OR. These experiments demonstrate the causal relationships among l-OR, the local/nanostructure evolutions, and the unusual electrochemistry. The TM migration triggered by the l-OR can change local oxygen coordination environments, which results in voltage hysteresis. Coupled with formed oxygen vacancies, it will accelerate the formation of nanopores, inducing a phase transition, and leading to irreversible capacity and long-cycling voltage fade.

14.
J Nutr Biochem ; 110: 109144, 2022 12.
Article in English | MEDLINE | ID: mdl-36057413

ABSTRACT

Lycopene (LYC) has been regarded as a nutraceutical that has powerful antioxidant and hepatoprotective bioactivities. In the present study, we aimed to investigate the beneficial effects of LYC on hepatic insulin signal transduction under oxidative stress conditions and the possible involvement of FGF21 and mitochondria pathways. Two-month-old CD-1 mice were treated by intraperitoneal injection of D-galactose (D-gal) 150 mg/kg/day for 8 weeks and received 0.03% LYC (w/w, mixed into diet). The results showed that LYC increased the expression of FGF21, alleviated mitochondrial dysfunction and improved hepatic insulin signal transduction in D-gal-treated mice. Furthermore, knockdown of FGF21 by small interfering RNA notably suppressed mitochondrial function and blunted LYC-stimulated insulin signal transduction in H2O2-treated HepG2 cells. Moreover, suppressed mitochondrial function via oligomycin also inhibited insulin signal transduction, indicating that LYC supplementation ameliorated oxidative stress-induced hepatic dysfunction of insulin signal transduction by up-regulating FGF21 and enhancing mitochondrial function.


Subject(s)
Hydrogen Peroxide , Insulin , Animals , Mice , Lycopene/pharmacology , Hydrogen Peroxide/metabolism , Insulin/metabolism , Oxidative Stress , Mitochondria/metabolism , Signal Transduction
15.
ACS Appl Mater Interfaces ; 14(34): 39046-39052, 2022 Aug 31.
Article in English | MEDLINE | ID: mdl-35981319

ABSTRACT

Ultraviolet photodetectors (UV PDs) have attracted extensive attention owing to their wide applications, such as optical communication, missile tracking, and fire warning. Wide-bandgap metal-oxide semiconductor materials have become the focus of high-performance UV PD development owing to their unique photoelectric properties and good stability. Compared with other wide-bandgap materials, studies on indium oxide (In2O3)-based photoelectrochemical (PEC) UV PDs are rare. In this work, we explore the photoresponse of In2O3-based PEC UV PDs for the first time. In2O3 microrods (MRs) were synthesized by a hydrothermal method with subsequent annealing. In2O3 MR PEC PDs have good UV photoresponse, showing a high responsivity of 21.19 mA/W and high specific detectivity of 2.03 × 1010 Jones, which surpass most aqueous-type PEC UV PDs. Moreover, In2O3 MR PEC PDs have good multicycle and long-term stability irradiated by 365 nm. Our results prove that In2O3 holds great promise in high-performance PEC UV PDs.

16.
J Am Chem Soc ; 144(33): 15193-15202, 2022 Aug 24.
Article in English | MEDLINE | ID: mdl-35926139

ABSTRACT

Data carriers using spin waves in spintronic and magnonic logic devices offer operation at low power consumption and free of Joule heating yet requiring noncollinear spin structures of small sizes. Heterometallic rings can provide such an opportunity due to the controlled spin-wave transmission within such a confined space. Here, we present a series of {ScnGdn} (n = 4, 6, 8) heterometallic rings, which are the first Sc-Ln clusters to date, with tunable magnetic interactions for spin-wave excitations. By means of time- and temperature-dependent spin dynamics simulations, we are able to predict distinct spin-wave excitations at finite temperatures for Sc4Gd4, Sc6Gd6, and Sc8Gd8. Such a new model is previously unexploited, especially due to the interplay of antiferromagnetic exchange, dipole-dipole interaction, and ring topology at low temperatures, rendering the importance of the latter to spin-wave excitations.

17.
Spectrochim Acta A Mol Biomol Spectrosc ; 281: 121606, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-35839694

ABSTRACT

2-Methylimidazole (MIM) is a classic organic ligand that shows excellent thermal stability and chemical robustness and is widely used in ZIFs. Recently, transformations of MOFs have been realized by using metals or ligands. In this study, we propose a new strategy-adjusting MIM by extending the alkyl chain length -to change the properties of related MOFs. Furthermore, we used copper as the metal core to replace zinc to mimic the active sites of laccases (electron transfer between copper and imidazole ring). As a result, the nanostructures transformed from nanoleaves to nanovesicles, which changed the Cu(II)/Cu(I) ratio from 3.7 to 1.7, as well as the lattice constant (decreased the diffraction angle) and enzyme-like activity (inhibition). In addition, we revealed that superoxidase anions were the main factors responsible for its laccase-like activity. We applied it to detect and discriminate phenolics. Laccase-mimicking activity was best at pH 7.0. When compared to protein laccase, the Cu-MeIm nanozyme had a greater Vmax at the same mass concentration. It was used to identify and distinguish phenolics. In the presence of Cu-MeIm nanozymes, the linear range is 0.1-2 mM and the detection limit of 2,4-DCP is 0.034 mM.


Subject(s)
Laccase , Nanostructures , Copper/chemistry , Laccase/chemistry , Laccase/metabolism , Ligands , Organic Chemicals , Phenols
18.
Materials (Basel) ; 15(3)2022 Jan 19.
Article in English | MEDLINE | ID: mdl-35160681

ABSTRACT

Thermal interface materials with high thermal conductivity and low hardness are crucial to the heat dissipation of high-power electronics. In this study, a high magnetic field was used to align the milled carbon fibers (CFs, 150 µm) in silicone rubber matrix to fabricate thermal interface materials with an ordered and discontinuous structure. The relationship among the magnetic field density, the alignment degree of CFs, and the properties of the resulting composites was explored by experimental study and theoretical analysis. The results showed higher alignment degree and enhanced thermal conductivity of composites under increased magnetic flux density within a certain curing time. When the magnetic flux density increased to 9 T, the CFs showed perfect alignment and the composite showed a high thermal conductivity of 11.76 W/(m·K) with only 20 vol% CF loading, owing to the ordered structure. Meanwhile, due to the low filler loading and discontinuous structure, a low hardness of 60~70 (shore 00) was also realized. Their thermal management performance was further confirmed in a test system, revealing promising applications for magnetic aligned CF-rubber composites in thermal interface materials.

19.
ACS Appl Mater Interfaces ; 14(5): 7175-7183, 2022 Feb 09.
Article in English | MEDLINE | ID: mdl-35099924

ABSTRACT

Two-dimensional (2D) bismuth oxychalcogenide (Bi2O2X, X refers to S, Se, and Te) is one type of rising semiconductor with excellent electrical transport properties, high photoresponse, and good air stability. However, the research on 2D Bi2O2S is limited. In this work, ultrathin Bi2O2S nanosheets are synthesized by a facile and eco-friendly chemical synthesis method at room temperature. The thickness and lateral sizes are 2-4 nm and 20-40 nm, respectively. The 2D ultrathin Bi2O2S nanosheets have a broad absorption spectrum from ultraviolet (UV) to near-infrared (NIR). Photoelectrochemical (PEC) photodetectors based on 2D Bi2O2S nanosheets are fabricated by a simple drop-casting method. The 2D Bi2O2S-based PEC photodetectors show excellent photodetection performance with a broad photoresponse spectrum from 365 to 850 nm, a high responsivity of 13.0 mA/W, ultrafast response times of 10/45 ms, and good long-term stability at a bias voltage of 0.6 V, which are superior to most 2D material-based PEC photodetectors. Further, the 2D Bi2O2S PEC photodetector can function as a high-performance self-powered broadband photodetector. Moreover, the photoresponse performance can be effectively tuned by the concentration and the kind of electrolyte. Our results demonstrate that 2D Bi2O2S nanosheets hold great promise for application in high-performance optoelectronic devices.

20.
Front Cell Infect Microbiol ; 12: 1074533, 2022.
Article in English | MEDLINE | ID: mdl-36776549

ABSTRACT

Introduction: As a deadly disease induced by Mycobacterium tuberculosis (Mtb), tuberculosis remains one of the top killers among infectious diseases. The low intracellular Mtb killing efficiency of current antibiotics introduced the long duration anti-TB therapy in clinic with strong side effects and increased drug-resistant mutants. Therefore, the exploration of novel anti-TB agents with potent anti-TB efficiency becomes one of the most urgent issues for TB therapies. Methods: Here, we firstly introduced a novel method for the preparation of zinc oxide-selenium nanoparticles (ZnO-Se NPs) by the hybridization of zinc oxide and selenium to combine the anti-TB activities of zinc oxide nanoparticles and selenium nanoparticles. We characterized the ZnO-Se NPs by dynamic laser light scattering and transmission electron microscopy, and then tested the inhibition effects of ZnO-Se NPs on extracellular Mtb by colony-forming units (CFU) counting, bacterial ATP analysis, bacterial membrane potential analysis and scanning electron microscopy imaging. We also analyzed the effects of ZnO-Se NPs on the ROS production, mitochondrial membrane potential, apoptosis, autophagy, polarization and PI3K/Akt/mTOR signaling pathway of Mtb infected THP-1 macrophages. At last, we also tested the effects of ZnO-Se NPs on intracellular Mtb in THP-1 cells by colony-forming units (CFU) counting. Results: The obtained spherical core-shell ZnO-Se NPs with average diameters of 90 nm showed strong killing effects against extracellular Mtb, including BCG and the virulent H37Rv, by disrupting the ATP production, increasing the intracellular ROS level and destroying the membrane structures. More importantly, ZnO-Se NPs could also inhibit intracellular Mtb growth by promoting M1 polarization to increase the production of antiseptic nitric oxide and also promote apoptosis and autophagy of Mtb infected macrophages by increasing the intracellular ROS, disrupting mitochondria membrane potential and inhibiting PI3K/Akt/mTOR signaling pathway. Discussion: These ZnO-Se NPs with synergetic anti-TB efficiency by combining the Mtb killing effects and host cell immunological inhibition effects were expected to serve as novel anti-TB agents for the development of more effective anti-TB strategy.


Subject(s)
Antitubercular Agents , Mycobacterium tuberculosis , Nanoparticles , Selenium , Zinc Oxide , Adenosine Triphosphate , Antitubercular Agents/pharmacology , Mycobacterium tuberculosis/drug effects , Nanoparticles/chemistry , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Reactive Oxygen Species , Selenium/pharmacology , TOR Serine-Threonine Kinases , Zinc Oxide/pharmacology , Zinc Oxide/chemistry
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