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1.
Angew Chem Int Ed Engl ; 63(9): e202317416, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38135667

RESUMO

Aminosilylene, comprising reactive NH- and Si(II) sites next to each other, is an intriguing class of compounds due to its ability to show diverse reactivity. However, stabilizing the reactive NH- group next to the free Si(II) atom is challenging and has not yet been achieved. Herein, we report the first examples of base stabilized free aminosilylenes Ar*NHSi(PhC(Nt Bu)2 ) (1 a) and Mes*NHSi(PhC(Nt Bu)2 ) (1 b) (Ar*=2,6-dibenzhydryl-4-methylphenyl and Mes*=2,4,6-tri-tert-butylphenyl), tolerating a NH- group next to the naked Si(II) atom. Remarkably, 1 a and 1 b exhibited interesting differences in their reactivity upon heating. With 1 a, an intramolecular C(sp3 )-H activation of one of the benzhydryl methine hydrogen atoms to the Si(II) atom produced the five-membered cyclic silazane 2. However, with 1 b, a rare 1,2-hydrogen shift to the Si(II) atom afforded a silanimine 3, with a hydride ligand attached to an unsaturated silicon atom. Further, the coordination capabilities of 1 a were also tested with Ru(II) and Fe(0) precursors. Treatments of 1 a with [Ru(η6 -p-cymene)Cl2 ]2 led to the isolation of a η6 -arene tethered complex [RuCl2 {Ar*NHSi(PhC(t BuN)2 )-κ1 -Si-η6 -arene}] (4), whereas with the Fe(CO)5 precursor a Fe(0) complex [Fe(CO)4 {Ar*NHSi(PhC(t BuN)2 )-κ1 -Si}] (5) was obtained. Density functional theory (DFT) calculations were conducted to shed light on the structural, bonding, and energetic aspects in 1-5.

2.
Ecotoxicol Environ Saf ; 256: 114872, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37027942

RESUMO

Manganese (Mn), as one of the environmental risk factors for Parkinson's disease (PD), has been widely studied. Though autophagy dysfunction and neuroinflammation mainly are responsible for the causative issue of Mn neurotoxicity, the molecular mechanism of parkinsonism caused by Mn has not been explored clearly. The results of in vivo and in vitro experiments showed that overexposure to Mn caused neuroinflammation impairment and autophagy dysfunction, accompanied by the increase of IL-1ß, IL-6, and TNF-α mRNA expression, and nerve cell apoptosis, microglia cell activation, NF-κB activation, poor neurobehavior performance. This is due to Mn-induced the downregulation of SIRT1. Upregulation of SIRT1 in vivo and in vitro could alleviate Mn-induced autophagy dysfunction and neuroinflammation, yet these beneficial effects were abolished following 3-MA administration. Furthermore, we found that Mn interfered with the acetylation of FOXO3 by SIRT1 in BV2 cells, leading to a decrease in the nuclear translocation of FOXO3, and its binding of LC3B promoter and transcription activity. This could be antagonized by the upregulation of SIRT1. Finally, it is proved that SIRT1/FOXO3-LC3B autophagy signaling involves in Mn-induced neuroinflammation impairment.


Assuntos
Manganês , Doenças Neuroinflamatórias , Autofagia , Proteína Forkhead Box O3/metabolismo , Manganês/metabolismo , Microglia , Sirtuína 1/metabolismo , Animais , Camundongos
3.
Cell Tissue Res ; 390(3): 367-383, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36201050

RESUMO

T helper 22 (Th22) cells have been implicated in diabetic retinopathy (DR), but it remains unclear whether Th22 cells involve in the pathogenesis of DR. To investigate the role of Th22 cells in DR mice, the animal models were established by intraperitoneal injection of STZ and confirmed by fundus fluorescein angiography and retinal haematoxylin-eosin staining. IL-22BP was administered by intravitreal injection. IL-22 level was measured by ELISA in vivo and in vitro. The expression of IL-22Rα1 in the retina was assessed by immunofluorescence. We assessed GFAP, VEGF, ICAM-1, inflammatory-associated factors and the integrity of blood-retinal barrier in control, DR, IL-22BP, and sham group. Müller cells were co-cultured with Th22 cells, and the expression of the above proteins was measured by immunoblotting. Plasmid transfection technique was used to silence Act1 gene in Müller cells. Results in vivo and in vitro indicated that Th22 cells infiltrated into the DR retinal and IL-22Rα1 expressed in Müller cells. Th22 cells promoted Müller cells activation and inflammatory factor secretion by secreting IL-22 compared with high-glucose stimulation alone. In addition, IL-22BP ameliorated the pathological alterations of the retina in DR. Inhibition of the inflammatory signalling cascade through Act1 knockdown alleviated DR-like pathology. All in all, the results suggested that Th22 cells infiltrated into the retina and secreted IL-22 in DR, and then IL-22 binding with IL-22Rα1 activated the Act1/TRAF6 signal pathway, and promoted the inflammatory of Müller cells and involved the pathogenesis of DR.


Assuntos
Diabetes Mellitus Experimental , Retinopatia Diabética , Camundongos , Animais , Células Ependimogliais/patologia , Fator 6 Associado a Receptor de TNF/metabolismo , Diabetes Mellitus Experimental/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Retina/metabolismo
4.
Int J Mol Sci ; 23(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36232647

RESUMO

The misuse and mismanagement of antibiotics have made the treatment of bacterial infections a challenge. This challenge is magnified when bacteria form biofilms, which can increase bacterial resistance up to 1000 times. It is desirable to develop anti-infective materials with antibacterial activity and no resistance to drugs. With the rapid development of nanotechnology, anti-infective strategies based on metal and metal oxide nanomaterials have been widely used in antibacterial and antibiofilm treatments. Here, this review expounds on the state-of-the-art applications of metal and metal oxide nanomaterials in bacterial infective diseases. A specific attention is given to the antibacterial mechanisms of metal and metal oxide nanomaterials, including disrupting cell membranes, damaging proteins, and nucleic acid. Moreover, a practical antibiofilm mechanism employing these metal and metal oxide nanomaterials is also introduced based on the composition of biofilm, including extracellular polymeric substance, quorum sensing, and bacteria. Finally, current challenges and future perspectives of metal and metal oxide nanomaterials in the anti-infective field are presented to facilitate their development and use.


Assuntos
Anti-Infecciosos , Infecções Bacterianas , Nanoestruturas , Ácidos Nucleicos , Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Bactérias/metabolismo , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Biofilmes , Matriz Extracelular de Substâncias Poliméricas , Humanos , Ácidos Nucleicos/metabolismo , Óxidos/metabolismo , Plâncton
5.
Chemistry ; 24(36): 8922-8940, 2018 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-29411433

RESUMO

Iron carbides and nitrides have aroused great interest in researchers, due to their excellent magnetic properties, good machinability and the particular catalytic activity. Based on these advantages, iron carbides and nitrides can be applied in various areas such as magnetic materials, biomedical, photo- and electrocatalysis. In contrast to their simple elemental composition, the synthesis of iron carbides and nitrides still has great challenges, particularly at the nanoscale, but it is usually beneficial to improve performance in corresponding applications. In this review, we introduce the investigations about iron carbides and nitrides, concerning their structure, synthesis strategy and various applications from magnetism to the catalysis. Furthermore, the future prospects are also discussed briefly.

6.
Chemistry ; 22(14): 4863-9, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-26934176

RESUMO

A series of Fe3C/C-Nx nanoparticles (NPs) with different nitrogen content are prepared by a simple one-pot route. In the synthetic procedure, aniline and acetonitrile are simultaneously used as the carbon and nitrogen source. The effect of calcination temperature on the structural and functional properties of the materials is investigated. Magnetic measurement shows that the sample prepared at 800 °C (Fe3 C/C-N800 NPs) possesses the highest Ms value of 77.2 emu g(-1). On testing as oxygen reduction reaction (ORR) catalysts, the sample prepared at 750 °C (Fe3C/C-N750 NPs) shows the best ORR performance among the series, with a more positive onset potential (+0.99 V vs. RHE), higher selectivity (number of electron transfer n≈3.93), longer durability, and stronger tolerance against methanol crossover than commercial Pt/C catalysts in a 0.1 m KOH solution. Moreover, in acidic solution, the excellent ORR activity and stability are also exhibited.

7.
Eur Radiol ; 25(4): 1140-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25537978

RESUMO

OBJECTIVE: The objective is to determine the timing and indications of transcatheter angiographic embolization (TAE) for delayed haemorrhage after percutaneous nephrolithotomy (PCNL). METHODS: The medical records of 144 patients who underwent arteriography and TAE for delayed post-PCNL haemorrhage at five university hospitals between January 2005 and December 2012 were reviewed retrospectively. RESULTS: The mean time to the onset of post-PCNL haemorrhage was 10.5 days (2 - 30 days). Clinical presentation included sudden onset bleeding in 51 patients (35.4 %), intermittent bleeding in 67 patients (46. 5 %), and continuous slow bleeding in 26 patients (18.1 %). Hemodynamic instability occurred in 32 patients (22.2 %). The mean haemoglobin decrease from the first post-PCNL day to the day of TAE was 49.5 g/L (31.0 - 79.0 g/L). Renal arteriography showed pseudoaneurysms in 69 (47.9 %) patients, arteriovenous fistulas in 28 (19.4 %) patients, mixed arterial and arteriovenous lesions in 17 (11.8 %) patients, arterial lacerations in 23 (16.0 %) patients, and negative angiographic finding in seven (4.9 %) patients. TAE was successful in stopping bleeding in all 137 patients with vascular lesions. There were no major complications associated with TAE. CONCLUSIONS: TAE should be the recommended treatment for delayed post-PCNL haemorrhage in patients with hemodynamic instability and/or corrected haemoglobin decrease >30 g/L following conservative management. KEY POINTS: • Delayed haemorrhage after percutaneous nephrolithotomy occurs more than 24 hours postoperatively. • Angio-embolization is a safe and effective treatment for delayed post-PCNL haemorrhage. • Angio-embolization can treat hemodynamic instability and/or corrected haemoglobin decrease >30 g/L.


Assuntos
Embolização Terapêutica , Hemorragia/etiologia , Hemorragia/terapia , Nefrostomia Percutânea/efeitos adversos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Artéria Renal/diagnóstico por imagem , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
8.
Langmuir ; 30(12): 3448-54, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24617527

RESUMO

Stimuli-responsive liquid marbles for controlled release typically rely on organic moieties that require lengthy syntheses. We report herein a facile, one-step synthesis of hydrophobic and oleophobic TiO2 nanoparticles that display photoresponsive wettability. Water liquid marbles stabilized by these photoresponsive TiO2 particles were found to be stable when shielded from ultraviolet (UV) radiation; however, they quickly collapsed after being irradiated with 302 nm UV light. Oil- and organic-solvent-based liquid marbles could also be fabricated using oleophobic TiO2 nanoparticles and show similar UV-induced collapse. Finally, we demonstrated the formation of the micronized form of water liquid marbles, also known as dry water, by homogenization of the TiO2 nanoparticles with water. The TiO2 dry water displayed a similar photoresponse, whereby the micronized liquid marbles collapsed after irradiation and the dry water turned from a free-flowing powder to a paste. Hence, by exploiting the photoresponsive wettability of TiO2, we fabricated liquid marbles and dry water that display photoresponse and studied the conditions required for their collapse.


Assuntos
Titânio/química , Raios Ultravioleta , Água/química , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Óleos/química , Tamanho da Partícula , Processos Fotoquímicos , Solventes/química , Propriedades de Superfície , Molhabilidade
9.
Dalton Trans ; 53(19): 8264-8268, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38656395

RESUMO

Boron compounds have attracted the attention of chemists because of their unique catalytic properties and potential wider material applications. Although group 13 metal compounds, which are based on the bis-(benzoxazol-2-yl)-methane system (Box, ({NCOC6H4}2CH2)), have been reported in the last several years, boron containing Box compounds were still missing. Now we report their successful syntheses and spectroscopic characterisation in this work. The borane compound [({NCOC6H3}2CH)BH2] (1) and haloboranes [({NCOC6H3}2CH)BF2] (2), [({NCOC6H3}2CH)BCl2] (3) and [({NCOC6H3}2CH)BBr2] (4) were characterised in the solid state by single crystal X-ray diffraction and in solution by NMR techniques. In addition, the fluorescence properties of compounds 1-4 are communicated.

10.
Dalton Trans ; 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39120603

RESUMO

In this work, an alane, [DNIAlH2] (1) (DNI = 3,3-dimethyl-2-[2-methyl-2-(2,6-diisopropyl-aniline)ethenyl]-3H-indolenine), stabilised by a hybrid ligand was reduced by Jones's Mg(I) ([(MesBDIMg)2]) and Roesky's Al(I) ([DippBDIAl:]). The resulting dialane compound [{DNI(H)Al}2] (2) was characterised using NMR spectroscopy, mass spectrometry, DFT calculations and single-crystal XRD experiments. The reaction of aluminium dihydride [DNIAlH2] (1) with [DippBDIAl:] at high temperatures gives an intramolecular C(sp2)-H bond-activated compound 3. To study the monomeric hybrid ligand-based Al(I), characterisations and computational calculations were performed, which elucidate that compound 5, consisting of two inequivalent aluminium atoms in an Al2CN four-membered ring, resulting from the activation of a carbon-nitrogen bond in the reaction of [DNINa] with [(Cp*Al)4].

11.
Biomed Pharmacother ; 170: 116053, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38118349

RESUMO

BACKGROUND: Endoplasmic reticulum (ER) stress-induced nerve cell damage has been known to be a hallmark feature of Mn-induced parkinsonism pathogenesis. However, several compensatory machineries, such as unfolded protein response (UPR), autophagy, and immune response, play an essential role in this damage, and the underlying molecular mechanisms are poorly understood. METHODS: Neurobehavioral impairment was assessed using catwalk gait analysis and open field test. RNA-seq analyzed the differentially expressed genes (DEGs). TUNEL staining and immunohistochemical analysis evaluated the nerve cells apoptosis and microglial cell activation. Flow cytometry assay measured microglia M1/M2 polarization. Western blotting measured protein expression. Immunofluorescence staining was used to observe the target molecules' subcellular localization. RESULTS: The study revealed that Mn caused a reduction in motor capacity, nerve cell apoptosis, and microglia activation with an imbalance in M1/M2 polarization, coupled with NF-κB signaling and PERK signaling activation. 4-PBA pretreatment could counteract these effects, while 3-MA administration exacerbated them. Additionally, autophagy could be activated by Mn. This activation could be further upregulated by 4-PBA pretreatment, whereas it was suppressed under 3-MA administration. Mn also decreased inactive GSK-3ß, increased STAT3 signaling activation, and increased colocalization of GSK-3ß and STAT3. These effects were strengthened by 4-PBA pretreatment, while 3-MA administration reversed them. DISCUSSION: This study suggests that autophagy and M2 microglia polarization might be protective in Mn-induced ER stress damage, possibly through GSK-3ß-ULK1 autophagy signaling and STAT3 signaling activation.


Assuntos
Manganês , Microglia , Humanos , Manganês/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Doenças Neuroinflamatórias , Estresse do Retículo Endoplasmático/fisiologia , Autofagia
12.
Nat Commun ; 15(1): 6825, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39122739

RESUMO

Graphene growth on widely used dielectrics/insulators via chemical vapor deposition (CVD) is a strategy toward transfer-free applications of CVD graphene for the realization of advanced composite materials. Here, we develop graphene-skinned alumina fibers/fabrics (GAFs/GAFFs) through graphene CVD growth on commercial alumina fibers/fabrics (AFs/AFFs). We reveal a vapor-surface-solid growth model on a non-metallic substrate, which is distinct from the well-established vapor-solid model on conventional non-catalytic non-metallic substrates, but bears a closer resemblance to that observed on catalytic metallic substrates. The metalloid-catalytic growth of graphene on AFs/AFFs resulted in reduced growth temperature (~200 °C lower) and accelerated growth rate (~3.4 times faster) compared to that obtained on a representative non-metallic counterpart, quartz fiber. The fabricated GAFF features a wide-range tunable electrical conductivity (1-15000 Ω sq-1), high tensile strength (>1.5 GPa), lightweight, flexibility, and a hierarchical macrostructure. These attributes are inherited from both graphene and AFF, making GAFF promising for various applications including electrical heating and electromagnetic interference shielding. Beyond laboratory level preparation, the stable mass production of large-scale GAFF has been achieved through a home-made roll-to-roll system with capacity of 468-93600 m2/year depending on product specifications, providing foundations for the subsequent industrialization of this material, enabling its widespread adoption in various industries.

13.
Sci Bull (Beijing) ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39060214

RESUMO

Direct synthesis of graphene on nonmetallic substrates via chemical vapor deposition (CVD) has become a frontier research realm targeting transfer-free applications of CVD graphene. However, the stable mass production of graphene with a favorable growth rate and quality remains a grand challenge. Herein, graphene glass fiber fabric (GGFF) was successfully developed through the controllable growth of graphene on non-catalytic glass fiber fabric, employing a synergistic binary-precursor CVD strategy to alleviate the dilemma between growth rate and quality. The binary precursors consisted of acetylene and acetone, where acetylene with high decomposition efficiency fed rapid graphene growth while oxygen-containing acetone was adopted for improving the layer uniformity and quality. Notably, the bifurcating introducing-confluent premixing (BI-CP) system was self-built for the controllable introduction of gas and liquid precursors, enabling the stable production of GGFF. GGFF features solar absorption and infrared emission properties, based on which the self-adaptive dual-mode thermal management film was developed. This film can automatically switch between heating and cooling modes by spontaneously perceiving the temperature, achieving excellent thermal management performances with heating and cooling power of ∼501.2 and ∼108.6 W m-2, respectively. These findings unlock a new strategy for the large-scale batch production of graphene materials and inspire advanced possibilities for further applications.

14.
Adv Mater ; 36(24): e2313752, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38576272

RESUMO

Conventional conductive materials such as metals are crucial functional components of conductive systems in diverse electronic instruments. However, their severe intrinsic impedance mismatch with air dielectric causes strong reflection of incident electromagnetic waves, and the resulting low electromagnetic transmissivity typically interferes with surrounding electromagnetic signal communications in modern multifunction-integrated instruments. Herein, graphene glass fiber fabric (GGFF) that merges intrinsic electrical and electromagnetic properties of graphene with dielectric attributes and highly porous macrostructure of glass fiber fabric (GFF) is innovatively developed. Using a novel decoupling chemical vapor deposition growth strategy, high-quality and layer-limited graphene is prepared on noncatalytic nonmetallic GFF in a controlled manner; this is pivotal to realizing GGFF with the desired compatibility among high conductivity, low electromagnetic reflectivity, and high electromagnetic transmissivity. At the same sheet resistance over a wide range of values (250-3000 Ω·sq-1), the GGFF exhibits significantly lower electromagnetic reflectivity (by 0.42-0.51) and higher transmissivity (by 0.27-0.62) than those of its metal-based conductive counterpart (CuGFF). The material design strategy reported herein provides a constructive solution to eliminate the incompatibility between electrical conductivity and electromagnetic transmissivity faced by conventional conductive materials, spotlighting the applicability of GGFF in electric heating scenarios in radar, antenna, and stealth systems.

15.
IUCrJ ; 10(Pt 6): 766-771, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910142

RESUMO

Phosphorus exists in several different allotropes: white, red, violet and black. For industrial and academic applications, white phosphorus is the most important. So far, three polymorphs of white phosphorus, all consisting of P4 tetrahedra, have been described. Among these, ß-P4 crystallizes in the space group P1 and γ-P4 in the space group C2/m. α-P4 forms soft plastic crystals with a proposed structure in the cubic space group I43m with the lattice constant a = 18.51 (3) Å, consisting of 58 rotationally disordered tetrahedra and thus is similar to the structure of α-Mn. Here we present a new polymorph, δ-P4. It crystallizes as a sixfold twin with the cell dimensions a = 18.302 (2), b = 18.302 (2), c = 36.441 (3) Šin the space group P212121 with 29 P4 tetrahedra in the asymmetric unit. The arrangement resembles the structure of α-Mn, but δ-P4 differs from α-P4. DFT calculations show δ-P4 to be metastable at a similar energy level to that of γ-P4.

16.
ACS Appl Mater Interfaces ; 15(5): 7578-7591, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36716404

RESUMO

The effective integration of multiple functions into electromagnetic wave-absorbing (EWA) materials is the future development direction but remains a huge challenge. A rational selection of components and the design of structures can make the material have excellent EWA performance and heat dissipation. Herein, the core-shell structured boron nitride@nitrogen-doped carbon (BN@NC) is prepared by using waterborne polyurethane (WPU) as the carbon source via a facile pyrolysis treatment process, where NC is used as the conductive loss shell, and BN serves as an impedance matching core and dominant heat transfer media. As a result, the BN@NC-900 filled with paraffin wax yields a minimum reflection loss of -42.2 dB at 2.2 mm and an effective absorbing bandwidth of 4.48 GHz at 1.8 mm, and its thermal conductivity reaches up to 0.92 W/m·K in epoxy resin. Most importantly, flexible BN@NC/WPU films are prepared and simultaneously achieve the dual-functional capability of efficiently dissipating heat and electromagnetic waves (-50.0 dB). Besides, an attractive multiband absorption feature (>99%) from C to Ku bands is realized and a strong absorbing over -27.0 dB at the S band (2.88 GHz) is even achieved. This study may pave a new route for the rational design of multifunctional EWA materials.

17.
Neuroscience ; 512: 47-58, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36509381

RESUMO

Diabetes is frequently accompanied by cognitive impairment with insidious onset, and progressive cognitive and behavioral changes. ß-1, 3-galactosyltransferase 2 (B3galt2) contributes to glycosylation, showing a clue for neuronal apoptosis, proliferation and differentiation. However, the role of B3galt2 in diabetic cognitive dysfunction (DCD) has not been investigated. In the present study, we aimed to explore the role of B3galt2 in DCD. Additionally, the potential therapeutic effects of salidroside on DCD was also explored. Diabetic C57BL/6J mice showed cognitive dysfunction together with down-regulated B3galt2. Overexpression of B3galt2 reversed the cognitive decline of diabetic C57BL/6J. Moreover, cognitive impairment was aggravated in B3galt2+/- diabetic mice compared with C57BL/6J diabetic mice. Immunohistochemistry fluorescence indicated that B3galt2 and F3/Contactin were co-localized in the hippocampal regions. Importantly, the expression of F3/Contactin can be regulated by the manipulation of B3galt2, overexpression of which assuaged hippocampal neuronal damage, protected the synapsin, and reduced neuronal apoptosis in diabetic mice. Interestingly, SAL alleviated DCD and reversed the expression of B3galt2 in diabetic C57BL/6J mice. These findings indicate that inhibition of B3galt2/F3/Contactin pathway contributes to DCD, and participates in SAL reversed DCD.


Assuntos
Disfunção Cognitiva , Diabetes Mellitus Experimental , Camundongos , Animais , Contactina 1/metabolismo , Camundongos Endogâmicos C57BL , Contactinas , Transdução de Sinais
18.
J Colloid Interface Sci ; 647: 43-51, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37244175

RESUMO

Hexagonal boron nitride (BN) is an attractive filler candidate for thermal interface materials, but the thermal conductivity enhancement is limited by the anisotropic thermal conductivity of BN and disordered thermal pathways in the polymer matrix. Herein, a facile and economic ice template method is proposed, wherein BN modified by tannic acid (BN-TA) directly self-assemble to form vertically aligned nacre-mimetic scaffold without additional binders and post-treatment. The effects of the BN slurry concentration and the ratio of BN/TA on three-dimensional (3D) skeleton morphology are fully investigated. The corresponding polydimethylsiloxane (PDMS) composite via vacuum-impregnation achieves a high through-plane thermal conductivity of 3.8 W/mK at a low filler loading of 18.7 vol%, which is 2433% and 100% higher than that of pristine PDMS and the PDMS composite with randomly distributed BN-TA, respectively. The finite element analysis results theoretically demonstrate the superiority of the highly longitudinally ordered 3D BN-TA skeleton in axial heat transfer. Additionally, 3D BN-TA/PDMS exhibits excellent practical heat dissipation capability, lower thermal expansion coefficient, and enhanced mechanical properties. This strategy offers an anticipated perspective for developing high-performance thermal interface materials to address the thermal challenges of modern electronics.

19.
Acta Diabetol ; 60(5): 631-644, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36717397

RESUMO

BACKGROUND: CD4 + T helper (Th)22 cells play a regulatory role in autoimmune diseases such as type 1 diabetes mellitus. The Th22-related cytokine interleukin (IL)-22, the expression of which is increased in diabetes mellitus (DM), can act as a neurotrophic factor to protect neurons from apoptosis. Paradoxically, neuronal apoptosis and learning and memory decline occur in DM. In this study, we investigated the relationship between IL-22 and its receptors IL-22Rα1 and IL-22 binding protein (IL-22BP, a soluble inhibitor of IL-22) in diabetic encephalopathy (DE) and the effects of IL-22 on hippocampal neurons, learning and memory. METHODS: A C57BL/6 mouse model of diabetes was constructed by intraperitoneal injection of streptozotocin. The mice were randomly divided into 4 groups: the control group, diabetes group, diabetes + recombinantIL-22 (rIL-22) group and diabetes + IL-22BP group. The Morris water maze test was used to evaluate learning and memory, the expression of IL-22 was measured by ELISA, and Evans Blue staining was used to evaluate blood-brain barrier permeability. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to measure the mRNA expression of IL-22 and IL-22Rα1 in the hippocampus. The morphology and number of hippocampal neurons were assessed by Nissl staining, and TUNEL staining was used to detect hippocampal neuronal apoptosis. Immunofluorescence was used to analyze IL-22Rα1 expression and localization in hippocampus, and Western blotting was used to evaluate the expression of IL-22, IL-22Rα1, IL-22BP, and the apoptosis related proteins Caspase-3 and C-caspase-3. RESULTS: Compared with those in the control group, mice in the diabetes group showed cognitive decline; apoptosis of hippocampal neurons; increased expression of hippocampal Caspase-3, C-Caspase-3, IL-22, IL-22Rα1, and IL-22BP; and a decreased IL-22/IL-22BP ratio. Learning and memory were improved, neuronal apoptosis was attenuated, IL-22Rα1 expression and the IL-22/IL-22BP ratio were increased, and caspase-3 and C-caspase-3 expression was decreased in the rIL-22-treated group compared with the diabetes group. IL-22BP treatment aggravated diabetic cognitive dysfunction and pathological alterations in the hippocampus, decreased the IL-22/IL-22BP ratio, and increased the expression of caspase-3 and C-caspase-3 in mice with diabetes. CONCLUSION: A decrease in the IL-22/IL-22BP ratio plays an important role in diabetic cognitive dysfunction, and rIL-22 can effectively alleviate DE. Herein, we shed light on the interaction between IL-22 and IL-22BP as therapeutic targets for DM.


Assuntos
Disfunção Cognitiva , Diabetes Mellitus Experimental , Ratos , Camundongos , Animais , Caspase 3/metabolismo , Ratos Sprague-Dawley , Diabetes Mellitus Experimental/metabolismo , Camundongos Endogâmicos C57BL , Disfunção Cognitiva/etiologia , Interleucinas/genética , Interleucinas/farmacologia , Interleucinas/uso terapêutico , Apoptose , Interleucina 22
20.
Adv Mater ; 35(18): e2209897, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36720106

RESUMO

Solar heating and radiative cooling techniques have been proposed for passive space thermal management to reduce the global energy burden. However, the currently used single-function envelope/coating materials can only achieve static temperature regulation, presenting limited energy savings and poor adaption to dynamic environments. In this study, a sandwich-structured fabric, composed of vertical graphene, graphene glass fiber fabric, and polyacrylonitrile nanofibers is developed, with heating and cooling functions integrated through multiband, synergistic, (solar spectrum and mid-infrared ranges) and asymmetric optical modulations on two sides of the fabric. The dual-function fabric demonstrates high adaption to the dynamic environment and superior performance in a zero-energy-input temperature regulation. Furthermore, it demonstrates ≈15.5 and ≈31.1 MJ m-2 y-1 higher annual energy savings compared to those of their cooling-only and heating-only counterparts, corresponding to ≈173.7 MT reduction in the global CO2 emission. The fabric exhibits high scalability for batch manufacturing with commercially abundant raw materials and facile technologies, providing a favorable guarantee of its mass production and use.

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