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1.
Front Immunol ; 15: 1423784, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39238645

RESUMO

Diabetic nephropathy, a common and severe complication of diabetes, is the leading cause of end-stage renal disease, ultimately leading to renal failure and significantly affecting the prognosis and lives of diabetics worldwide. However, the complexity of its developmental mechanisms makes treating diabetic nephropathy a challenging task, necessitating the search for improved therapeutic targets. Intercellular communication underlies the direct and indirect influence and interaction among various cells within a tissue. Recently, studies have shown that beyond traditional communication methods, tunnel nanotubes, exosomes, filopodial tip vesicles, and the fibrogenic niche can influence pathophysiological changes in diabetic nephropathy by disrupting intercellular communication. Therefore, this paper aims to review the varied roles of intercellular communication in diabetic nephropathy, focusing on recent advances in this area.


Assuntos
Comunicação Celular , Nefropatias Diabéticas , Exossomos , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/metabolismo , Humanos , Animais , Exossomos/metabolismo
2.
Adv Mater ; : e2407889, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39240011

RESUMO

Electrochemical nitrate reduction reaction (NO3RR) is emerging as a promising strategy for nitrate removal and ammonia (NH3) production using renewable electricity. Although great progresses have been achieved, the crystal phase effect of electrocatalysts on NO3RR remains rarely explored. Here, the epitaxial growth of unconventional 2H Cu on hexagonal close-packed (hcp) IrNi template, resulting in the formation of three IrNiCu@Cu nanostructures, is reported. IrNiCu@Cu-20 shows superior catalytic performance, with NH3 Faradaic efficiency (FE) of 86% at -0.1 (vs reversible hydrogen electrode [RHE]) and NH3 yield rate of 687.3 mmol gCu -1 h-1, far better than common face-centered cubic Cu. In sharp contrast, IrNiCu@Cu-30 and IrNiCu@Cu-50 covered by hcp Cu shell display high selectivity toward nitrite (NO2 -), with NO2 - FE above 60% at 0.1 (vs RHE). Theoretical calculations have demonstrated that the IrNiCu@Cu-20 has the optimal electronic structures for NO3RR due to the highest d-band center and strongest reaction trend with the lowest energy barriers. The high electroactivity of IrNiCu@Cu-20 originates from the abundant low coordination of Cu sites on the surface, which guarantees the fast electron transfer to accelerate the intermediate conversions. This work provides a feasible tactic to regulate the product distribution of NO3RR by crystal phase engineering of electrocatalysts.

3.
Int J Biol Macromol ; 278(Pt 2): 134677, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39142478

RESUMO

Complex and stubborn bacterial biofilm infections significantly hinder diabetic wound healing and threaten public health. Therefore, a dressing material that effectively clears biofilms and promotes wound healing is urgently required. Herein, we introduce a novel strategy for simultaneously dispersing extracellular polymeric substances and eradicating drug-resistant bacteria. We prepared an ultrabroad-spectrum and injectable quaternized chitosan (QCS) hydrogel loaded with trypsin, which degrades biofilm extracellular proteins. Increased temperature initiated QCS gelation to form the hydrogel, enabling the sustained release of trypsin and effective adherence of the hydrogel to irregularly shaped wounds. To reproduce clinical scenarios, biofilms formed by a mixture of Staphylococcus aureus (S. aureus), Methicillin-resistant S. aureus, and Pseudomonas aeruginosa were administered to the wounds of rats with streptozotocin-induced diabetes. Under these severe infection conditions, the hydrogel efficiently suppressed inflammation, promoted angiogenesis, and enhanced collagen deposition, resulting in accelerated healing of diabetic wounds. Notably, the hydrogel demonstrates excellent biocompatibility without cytotoxicity. In summary, we present a trypsin-loaded QCS hydrogel with tremendous clinical applications potential for the treatment of chronic infected wounds.


Assuntos
Biofilmes , Quitosana , Diabetes Mellitus Experimental , Hidrogéis , Tripsina , Cicatrização , Biofilmes/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Ratos , Tripsina/química , Tripsina/metabolismo , Diabetes Mellitus Experimental/complicações , Antibacterianos/farmacologia , Antibacterianos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Masculino , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Matriz Extracelular de Substâncias Poliméricas/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos
4.
J Nanobiotechnology ; 22(1): 399, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38970101

RESUMO

Spinal cord injury (SCI) represents a profound central nervous system affliction, resulting in irreversibly compromised daily activities and disabilities. SCI involves excessive inflammatory responses, which are characterized by the existence of high levels of proinflammatory M1 macrophages, and neuronal mitochondrial energy deficit, exacerbating secondary damage and impeding axon regeneration. This study delves into the mechanistic intricacies of SCI, offering insights from the perspectives of neuroimmune regulation and mitochondrial function, leading to a pro-fibrotic macrophage phenotype and energy-supplying deficit. To address these challenges, we developed a smart scaffold incorporating enzyme mimicry nanoparticle-ceriumoxide (COPs) into nanofibers (NS@COP), which aims to pioneer a targeted neuroimmune repair strategy, rescuing CGRP receptor on macrophage and concurrently remodeling mitochondrial function. Our findings indicate that the integrated COPs restore the responsiveness of pro-inflammatory macrophages to calcitonin gene-related peptide (CGRP) signal by up-regulating receptor activity modifying protein 1 (RAMP1), a vital component of the CGRP receptor. This promotes macrophage fate commitment to an anti-inflammatory pro-resolution M2 phenotype, then alleviating glial scar formation. In addition, NS@COP implantation also protected neuronal mitochondrial function. Collectively, our results suggest that the strategy of integrating nanozyme COP nanoparticles into a nanofiber scaffold provides a promising therapeutic candidate for spinal cord trauma via rational regulation of neuroimmune communication and mitochondrial function.


Assuntos
Axônios , Macrófagos , Nanofibras , Regeneração Nervosa , Traumatismos da Medula Espinal , Animais , Axônios/metabolismo , Nanofibras/química , Regeneração Nervosa/efeitos dos fármacos , Camundongos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Ratos , Alicerces Teciduais/química , Nanopartículas/química , Ratos Sprague-Dawley , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Feminino , Camundongos Endogâmicos C57BL
5.
Small ; : e2402632, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012068

RESUMO

Porous carbon nanomaterials are widely applied in the electromagnetic wave absorption (EMWA) field. Among them, an emerging flower-like carbon nanomaterial, termed carbon nanoflowers (CNFs), has attracted tremendous research attention due to their unique hierarchical flower-like structure. However, the design of flower-like carbon nanomaterials with different magnetic cores for EMWA has rarely been reported. Herein, a general template method is proposed to achieve a set of high-quality magnetic CNFs, namely Co@Void@CNFs, CoNi@CNFs, and Ni@CNFs. The prepared magnetic CNFs have highly accessible surface area and internal space, rich heteroatom content, multi-scale pore system, and uniform and highly dispersed magnetic nanoparticles, as a result, deliver superior EMWA performance. Specifically, when the thickness is 2.6 mm, the Co@Void@CNFs exhibit a maximum refection loss (RLmax) of -56.6 dB and an effective absorption bandwidth (EAB) from 8.0 to 12.1 GHz covering the whole X band. The CoNi@CNFs have an RLmax of up to -57.6 dB and a wide EAB of 5.6 GHz at just 1.9 mm. For the Ni@CNFs, possess an ultra-broad EAB of 6.1 GHz, covering the entire Ku band at 2.0 mm. Overall, the hierarchical magnetic carbon nanoflowers proposed here offer new insights toward realizing multifunctional integrated carbon nanomaterials for EMWA.

6.
Environ Sci Technol ; 58(24): 10863-10873, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38842426

RESUMO

Electrochemical nitrate reduction (NO3RR) provides a new option to abate nitrate contamination with a low carbon footprint. Restricted by competitive hydrogen evolution, achieving satisfied nitrate reduction performance in neutral media is still a challenge, especially for the regulation of this multielectron multiproton reaction. Herein, facile element doping is adopted to tune the catalytic behavior of IrNi alloy nanobranches with an unconventional hexagonal close-packed (hcp) phase toward NO3RR. In particular, the obtained hcp IrNiCu nanobranches favor the ammonia production and suppress byproduct formation in a neutral electrolyte indicated by in situ differential electrochemical mass spectrometry, with a high Faradaic efficiency (FE) of 85.6% and a large yield rate of 1253 µg cm-2 h-1 at -0.4 and -0.6 V (vs reversible hydrogen electrode (RHE)), respectively. In contrast, the resultant hcp IrNiCo nanobranches promote the formation of nitrite, with a peak FE of 33.1% at -0.1 V (vs RHE). Furthermore, a hybrid electrolysis cell consisting of NO3RR and formaldehyde oxidation is constructed, which are both catalyzed by hcp IrNiCu nanobranches. This electrolyzer exhibits lower overpotential and holds the potential to treat polluted air and wastewater simultaneously, shedding light on green chemical production based on contaminate degradation.


Assuntos
Nitratos , Oxirredução , Nitratos/química , Técnicas Eletroquímicas , Catálise , Metais/química
7.
BMC Public Health ; 24(1): 1724, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943103

RESUMO

Public health events (PHEs) have emerged as significant threats to human life, health, and economic growth. PHEs, such as COVID-19, have prompted a reevaluation for enhanced regular prevention and control (RPC). In this study, we focus on the core concept of prevention and control intensity (PCI), and establish a neoclassical economic growth model from the long-term and macro perspective to balance life protection and economic growth. The model construct the mechanism of PCI on economic growth through population dynamics and capital accumulation under the backdrop of RPC for PHEs. We find the conditions for PCI when the economy achieves steady state, and provides an algorithm establishing the optimal strategy that maximises per capita disposable income based on the optimal PCI and consumption. Simulation result quantifies an inverted U-shaped relationship between PCI and capital per capita, output per capita and consumption per capita in the steady state. The model suggests that, given the PHEs of inducing potential unemployment shock, it is worthwhile to combine the implementation of moderate PCI with coordinated policies of income distribution.


Assuntos
COVID-19 , Desenvolvimento Econômico , Saúde Pública , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Modelos Econômicos
8.
Small Methods ; : e2400432, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767183

RESUMO

Electrocatalytic carbon dioxide reduction reaction (CO2RR) has emerged as a promising and sustainable approach to cut carbon emissions by converting greenhouse gas CO2 to value-added chemicals and fuels. Metal-organic coordination compounds, especially the copper (Cu)-based coordination compounds, which feature well-defined crystalline structures and designable metal active sites, have attracted much research attention in electrocatalytic CO2RR. Herein, the recent advances of electrochemical CO2RR on pristine Cu-based coordination compounds with different types of Cu active sites are reviewed. First, the general reaction pathways of electrocatalytic CO2RR on Cu-based coordination compounds are briefly introduced. Then the highly efficient conversion of CO2 on various kinds of Cu active sites (e.g., single-Cu site, dimeric-Cu site, multi-Cu site, and heterometallic site) is systematically discussed, along with the corresponding catalytic reaction mechanisms. Finally, some existing challenges and potential opportunities for this research direction are provided to guide the rational design of metal-organic coordination compounds for their practical application in electrochemical CO2RR.

9.
Adv Mater ; 36(32): e2402979, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38811011

RESUMO

Copper (Cu) nanomaterials are a unique kind of electrocatalysts for high-value multi-carbon production in carbon dioxide reduction reaction (CO2RR), which holds enormous potential in attaining carbon neutrality. However, phase engineering of Cu nanomaterials remains challenging, especially for the construction of unconventional phase Cu-based asymmetric heteronanostructures. Here the site-selective growth of Cu on unusual phase gold (Au) nanorods, obtaining three kinds of heterophase fcc-2H-fcc Au-Cu heteronanostructures is reported. Significantly, the resultant fcc-2H-fcc Au-Cu Janus nanostructures (JNSs) break the symmetric growth mode of Cu on Au. In electrocatalytic CO2RR, the fcc-2H-fcc Au-Cu JNSs exhibit excellent performance in both H-type and flow cells, with Faradaic efficiencies of 55.5% and 84.3% for ethylene and multi-carbon products, respectively. In situ characterizations and theoretical calculations reveal the co-exposure of 2H-Au and 2H-Cu domains in Au-Cu JNSs diversifies the CO* adsorption configurations and promotes the CO* spillover and subsequent C-C coupling toward ethylene generation with reduced energy barriers.

10.
Angew Chem Int Ed Engl ; 63(26): e202402841, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38647519

RESUMO

The controlled synthesis of metal nanomaterials with unconventional phases is of significant importance to develop high-performance catalysts for various applications. However, it remains challenging to modulate the atomic arrangements of metal nanomaterials, especially the alloy nanostructures that involve different metals with distinct redox potentials. Here we report the general one-pot synthesis of IrNi, IrRhNi and IrFeNi alloy nanobranches with unconventional hexagonal close-packed (hcp) phase. Notably, the as-synthesized hcp IrNi nanobranches demonstrate excellent catalytic performance towards electrochemical nitrite reduction reaction (NO2RR), with superior NH3 Faradaic efficiency and yield rate of 98.2 % and 34.6 mg h-1 mgcat -1 (75.5 mg h-1 mgIr -1) at 0 and -0.1 V (vs reversible hydrogen electrode), respectively. Ex/in situ characterizations and theoretical calculations reveal that the Ir-Ni interactions within hcp IrNi alloy improve electron transfer to benefit both nitrite activation and active hydrogen generation, leading to a stronger reaction trend of NO2RR by greatly reducing energy barriers of rate-determining step.

11.
Adv Mater ; 36(27): e2403154, 2024 Jul.
Artigo em Holandês | MEDLINE | ID: mdl-38631700

RESUMO

Van der Waals (vdW) ferromagnetic materials have emerged as a promising platform for the development of 2D spintronic devices. However, studies to date are restricted to vdW ferromagnetic materials with low Curie temperature (Tc) and small magnetic anisotropy. Here, a chemical vapor transport method is developed to synthesize a high-quality room-temperature ferromagnet, Fe3GaTe2 (c-Fe3GaTe2), which boasts a high Tc = 356 K and large perpendicular magnetic anisotropy. Due to the planar symmetry breaking, an unconventional room-temperature antisymmetric magnetoresistance (MR) is first observed in c-Fe3GaTe2 devices with step features, manifesting as three distinctive states of high, intermediate, and low resistance with the sweeping magnetic field. Moreover, the modulation of the antisymmetric MR is demonstrated by controlling the height of the surface steps. This work provides new routes to achieve magnetic random storage and logic devices by utilizing the room-temperature thickness-controlled antisymmetric MR and further design room-temperature 2D spintronic devices based on the vdW ferromagnet c-Fe3GaTe2.

12.
Micromachines (Basel) ; 15(4)2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38675293

RESUMO

Piezoelectric micromachined ultrasound transducers (PMUTs) have gained significant popularity in the field of ultrasound ranging and medical imaging owing to their small size, low power consumption, and affordability. The scar-free "MIS" (micro-hole inter-etch and sealing) process, a novel bulk-silicon manufacturing technique, has been successfully developed for the fabrication of pressure sensors, flow sensors, and accelerometers. In this study, we utilize the MIS process to fabricate cavity diaphragm structures for PMUTs, resulting in the formation of a flat cavity diaphragm structure through anisotropic etching of (111) wafers in a 70 °C tetramethylammonium hydroxide (TMAH) solution. This study investigates the corrosion characteristics of the MIS technology on (111) silicon wafers, arranges micro-pores etched on bulk silicon around the desired cavity structure in a regular pattern, and takes into consideration the distance compensation for lateral corrosion, resulting in a fully connected cavity structure closely approximating an ortho-hexagonal shape. By utilizing a sputtering process to deposit metallic molybdenum as upper and lower electrodes, as well as piezoelectric materials above the cavity structure, we have successfully fabricated aluminum nitride (AlN) piezoelectric ultrasonic transducer arrays of various sizes and structures. The final hexagonal PMUT cells of various sizes that were fabricated achieved a maximum quality factor (Q) of 251 and a displacement sensitivity of 18.49 nm/V across a range of resonant frequencies from 6.28 MHz to 11.99 MHz. This fabrication design facilitates the achievement of IC-compatible and cost-effective mass production of PMUT array devices with high resonance frequencies.

13.
ACS Nano ; 18(9): 7192-7203, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38385434

RESUMO

Electrocatalytic carbon dioxide reduction reaction (CO2RR) toward value-added chemicals/fuels has offered a sustainable strategy to achieve a carbon-neutral energy cycle. However, it remains a great challenge to controllably and precisely regulate the coordination environment of active sites in catalysts for efficient generation of targeted products, especially the multicarbon (C2+) products. Herein we report the coordination environment engineering of metal centers in coordination polymers for efficient electroreduction of CO2 to C2+ products under neutral conditions. Significantly, the Cu coordination polymer with Cu-N2S2 coordination configuration (Cu-N-S) demonstrates superior Faradaic efficiencies of 61.2% and 82.2% for ethylene and C2+ products, respectively, compared to the selective formic acid generation on an analogous polymer with the Cu-I2S2 coordination mode (Cu-I-S). In situ studies reveal the balanced formation of atop and bridge *CO intermediates on Cu-N-S, promoting C-C coupling for C2+ production. Theoretical calculations suggest that coordination environment engineering can induce electronic modulations in Cu active sites, where the d-band center of Cu is upshifted in Cu-N-S with stronger selectivity to the C2+ products. Consequently, Cu-N-S displays a stronger reaction trend toward the generation of C2+ products, while Cu-I-S favors the formation of formic acid due to the suppression of C-C couplings for C2+ pathways with large energy barriers.

14.
Adv Mater ; 36(14): e2313548, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38279631

RESUMO

Electrocatalytic nitrate reduction reaction (NO3RR) toward ammonia synthesis is recognized as a sustainable strategy to balance the global nitrogen cycle. However, it still remains a great challenge to achieve highly efficient ammonia production due to the complex proton-coupled electron transfer process in NO3RR. Here, the controlled synthesis of RuMo alloy nanoflowers (NFs) with unconventional face-centered cubic (fcc) phase and hexagonal close-packed/fcc heterophase for highly efficient NO3RR is reported. Significantly, fcc RuMo NFs demonstrate high Faradaic efficiency of 95.2% and a large yield rate of 32.7 mg h-1 mgcat -1 toward ammonia production at 0 and -0.1 V (vs reversible hydrogen electrode), respectively. In situ characterizations and theoretical calculations have unraveled that fcc RuMo NFs possess the highest d-band center with superior electroactivity, which originates from the strong Ru─Mo interactions and the high intrinsic activity of the unconventional fcc phase. The optimal electronic structures of fcc RuMo NFs supply strong adsorption of key intermediates with suppression of the competitive hydrogen evolution, which further determines the remarkable NO3RR performance. The successful demonstration of high-performance zinc-nitrate batteries with fcc RuMo NFs suggests their substantial application potential in electrochemical energy supply systems.

15.
Nano Lett ; 24(5): 1553-1562, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38266492

RESUMO

Although metal-organic frameworks (MOFs) have attracted more attention for the electrocatalytic CO2 reduction reaction (CO2RR), obtaining multicarbon products with a high Faradaic efficiency (FE) remains challenging, especially under neutral conditions. Here, we report the controlled synthesis of stable Cu(I) 5-mercapto-1-methyltetrazole framework (Cu-MMT) nanostructures with different facets by rationally modulating the reaction solvents. Significantly, Cu-MMT nanostructures with (001) facets are acquired using isopropanol as a solvent, which favor multicarbon production with an FE of 73.75% and a multicarbon:single-carbon ratio of 3.93 for CO2RR in a neutral electrolyte. In sharp contrast, Cu-MMT nanostructures with (100) facets are obtained utilizing water, promoting single-carbon generation with an FE of 63.98% and a multicarbon: single-carbon ratio of only 0.18. Furthermore, this method can be extended to other Cu-MMT nanostructures with different facets in tuning the CO2 reduction selectivity. This work opens up new opportunities for the highly selective and efficient CO2 electroreduction to multicarbon products on MOFs via facet engineering.

16.
Spine (Phila Pa 1976) ; 49(5): 321-331, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38073193

RESUMO

STUDY DESIGN: This is a cross-sectional study. OBJECTIVE: To evaluate the effectiveness of a novel finger Kinematic Parameter-Based Tool in the grip and release (G&R) test for assessing degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: The development and progression of DCM symptoms are gradual and obscure. Although previous studies have objectively evaluated hand movements specific to myelopathy using the G&R test, virtual reality, or wearable sensors, these methods have limitations, such as limited discrimination or inconvenience for simple screening. Consequently, there is a need to develop effective screening methods. MATERIALS AND METHODS: Totally, 297 asymptomatic volunteers and 258 DCM patients were enrolled. This system comprises a wearable acceleration/gyro sensor. The acceleration/gyro sensor was placed on the little finger of the participants to perform 40 cycles of full-range G&R as quickly as possible. The collected data were then transformed into kinematic parameters using sensor-based software and R studio software (version: RStudio 2022.07.2+576, Boston, USA). Gender, age, and body mass index (BMI) subgroups (classified as BMI<18.5-below normal weight; 18.5≤BMI<25-normal weight group; BMI≥25-overweight group) were matched as predictor variables, and 201 pairs were matched. Nonparametric analysis using the Mann-Whitney U test was used for diagnosing the differences between the two groups, and Kruskal-Wallis's test followed by the Mann-Whitney U test was used for analyzing the differences among three different age groups (<40, 41-60, and >60 yr group). The cut-off value of 10s G&R cycles and a combined parameter were determined using receiver operating characteristics curve analysis, area under the curve, and Youden index. RESULTS: The authors found that little finger kinematic parameters were significantly lower in DCM patients than in asymptomatic participants. The optimal diagnostic indicator appeared to be the average of the top 10 linear accelerations with an area under the curve of 0.923. CONCLUSION: The Finger Kinematic Test System is an objective, practical, and quantitative utility that appears to have the capacity to diagnose and evaluate the severity of DCM. LEVEL OF EVIDENCE: 3.


Assuntos
Vértebras Cervicais , Doenças da Medula Espinal , Humanos , Projetos Piloto , Estudos Transversais , Fenômenos Biomecânicos , Doenças da Medula Espinal/diagnóstico
17.
Nat Biotechnol ; 42(4): 591-596, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37349523

RESUMO

Current N6-methyladenosine (m6A) mapping methods need large amounts of RNA or are limited to cultured cells. Through optimized sample recovery and signal-to-noise ratio, we developed picogram-scale m6A RNA immunoprecipitation and sequencing (picoMeRIP-seq) for studying m6A in vivo in single cells and scarce cell types using standard laboratory equipment. We benchmark m6A mapping on titrations of poly(A) RNA and embryonic stem cells and in single zebrafish zygotes, mouse oocytes and embryos.


Assuntos
RNA , Peixe-Zebra , Animais , Camundongos , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , RNA/genética , RNA Mensageiro/genética , Células-Tronco Embrionárias , Células Cultivadas
18.
PLoS Biol ; 21(12): e3002429, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38079456

RESUMO

Motile bacteria navigate toward favorable conditions and away from unfavorable environments using chemotaxis. Mechanisms of sensing attractants are well understood; however, molecular aspects of how bacteria sense repellents have not been established. Here, we identified malate as a repellent recognized by the MCP2201 chemoreceptor in a bacterium Comamonas testosteroni and showed that it binds to the same site as an attractant citrate. Binding determinants for a repellent and an attractant had only minor differences, and a single amino acid substitution in the binding site inverted the response to malate from a repellent to an attractant. We found that malate and citrate affect the oligomerization state of the ligand-binding domain in opposing way. We also observed opposing effects of repellent and attractant binding on the orientation of an alpha helix connecting the sensory domain to the transmembrane helix. We propose a model to illustrate how positive and negative signals might be generated.


Assuntos
Proteínas de Bactérias , Malatos , Proteínas Quimiotáticas Aceptoras de Metil/química , Proteínas de Bactérias/metabolismo , Ligantes , Escherichia coli/metabolismo , Quimiotaxia/fisiologia , Bactérias/metabolismo , Citratos
19.
Proc Natl Acad Sci U S A ; 120(50): e2311149120, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38064508

RESUMO

Zinc-nitrate batteries can integrate energy supply, ammonia electrosynthesis, and sewage disposal into one electrochemical device. However, current zinc-nitrate batteries still severely suffer from the limited energy density and poor rechargeability. Here, we report the synthesis of tetraphenylporphyrin (tpp)-modified heterophase (amorphous/crystalline) rhodium-copper alloy metallenes (RhCu M-tpp). Using RhCu M-tpp as a bifunctional catalyst for nitrate reduction reaction (NO3RR) and ethanol oxidation reaction in neutral solution, a highly rechargeable and low-overpotential zinc-nitrate/ethanol battery is successfully constructed, which exhibits outstanding energy density of 117364.6 Wh kg-1cat, superior rate capability, excellent cycling stability of ~400 cycles, and potential ammonium acetate production. Ex/in situ experimental studies and theoretical calculations reveal that there is a molecule-metal relay catalysis in NO3RR over RhCu M-tpp that significantly facilitates the ammonia selectivity and reaction kinetics via a low energy barrier pathway. This work provides an effective design strategy of multifunctional metal-based catalysts toward the high-performance zinc-based hybrid energy systems.

20.
Bone Res ; 11(1): 48, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37669953

RESUMO

Recent studies have determined that the nervous system can sense and respond to signals from skeletal tissue, a process known as skeletal interoception, which is crucial for maintaining bone homeostasis. The hypothalamus, located in the central nervous system (CNS), plays a key role in processing interoceptive signals and regulating bone homeostasis through the autonomic nervous system, neuropeptide release, and neuroendocrine mechanisms. These mechanisms control the differentiation of mesenchymal stem cells into osteoblasts (OBs), the activation of osteoclasts (OCs), and the functional activities of bone cells. Sensory nerves extensively innervate skeletal tissues, facilitating the transmission of interoceptive signals to the CNS. This review provides a comprehensive overview of current research on the generation and coordination of skeletal interoceptive signals by the CNS to maintain bone homeostasis and their potential role in pathological conditions. The findings expand our understanding of intersystem communication in bone biology and may have implications for developing novel therapeutic strategies for bone diseases.


Assuntos
Doenças Ósseas , Sistema Nervoso Central , Humanos , Homeostase , Vias Aferentes , Sistema Nervoso Autônomo
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