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1.
Nano Lett ; 24(20): 6002-6009, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38739273

RESUMO

Two-dimensional van der Waals heterostructures (2D-vdWHs) based on transition metal dichalcogenides (TMDs) provide unparalleled control over electronic properties. However, the interlayer coupling is challenged by the interfacial misalignment and defects, which hinders a comprehensive understanding of the intertwined electronic orders, especially superconductivity and charge density wave (CDW). Here, by using pressure to regulate the interlayer coupling of non-centrosymmetric 6R-TaS2 vdWHs, we observe an unprecedented phase diagram in TMDs. This phase diagram encompasses successive suppression of the original CDW states from alternating H-layer and T-layer configurations, the emergence and disappearance of a new CDW-like state, and a double superconducting dome induced by different interlayer coupling effects. These results not only illuminate the crucial role of interlayer coupling in shaping the complex phase diagram of TMD systems but also pave a new avenue for the creation of a novel family of bulk heterostructures with customized 2D properties.

2.
Anal Chem ; 96(16): 6112-6121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38554137

RESUMO

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique for chemical identification, but it remains a great challenge to realize the large-scale and well-controlled fabrication of sensitive and repeatable SERS substrates. Here, we report a facile strategy to fabricate centimeter-sized periodic Au nanograting (Au-NG) decorated with well-arranged Ag nanoparticles (Ag-NPs) (denoted as Ag-NPs@Au-NG) as a three-dimensional (3D) flexible hybrid SERS substrate with high sensitivity and good reproducibility. The Au-NG patterns with periodic ridges and grooves are fabricated through nanoimprint lithography by employing a low-cost digital versatile disc (DVD) as a master mold, and the Ag-NPs are assembled by a well-controlled interface self-assembly method without any coupling agents. Multiple coupling electromagnetic field effects are created at the nanogaps between the Ag-NPs and Au-NG patterns, leading to high-density and uniform hot spots throughout the substrate. As a result, the Ag-NPs@Au-NG arrays demonstrate an ultrahigh SERS sensitivity as low as 10-13 M for rhodamine 6G with a high average enhancement factor (EF) of 1.85 × 108 and good signal reproducibility. For practical applications, toxic organic pollutants including crystal violet, thiram, and melamine have been successfully detected with high sensitivity at a low detection limit, showing a good perspective in the rapid detection of toxic organic pollutants.

3.
Small ; 20(27): e2310530, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38317526

RESUMO

Rechargeable aprotic Li-CO2 batteries have aroused worldwide interest owing to their environmentally friendly CO2 fixation ability and ultra-high specific energy density. However, its practical applications are impeded by the sluggish reaction kinetics and discharge product accumulation during cycling. Herein, a flexible composite electrode comprising CoSe2 nanoparticles embedded in 3D carbonized melamine foam (CoSe2/CMF) for Li-CO2 batteries is reported. The abundant CoSe2 clusters can not only facilitate CO2 reduction/evolution kinetics but also serve as Li2CO3 nucleation sites for homogeneous discharge product growth. The CoSe2/CMF-based Li-CO2 battery exhibits a large initial discharge capacity as high as 5.62 mAh cm-2 at 0.05 mA cm-2, a remarkably small voltage gap of 0.72 V, and an ultrahigh energy efficiency of 85.9% at 0.01 mA cm-2, surpassing most of the noble metal-based catalysts. Meanwhile, the battery demonstrates excellent cycling stability of 1620 h (162 cycles) at 0.02 mA cm-2 with an average overpotential of 0.98 V and energy efficiency of 85.4%. Theoretical investigations suggest that this outstanding performance is attributed to the suitable CO2/Li adsorption and low Li2CO3 decomposition energy. Moreover, flexible Li-CO2 pouch cell with CoSe2/CMF cathode displays stable power output under different bending deformations, showing promising potential in wearable electronic devices.

4.
Mol Psychiatry ; 28(9): 3795-3805, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37658228

RESUMO

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders with a strong genetic liability. Despite extensive studies, however, the underlying pathogenic mechanism still remains elusive. In the present study, we identified a homozygous mutation in the intron 1 of Wnt1 via large-scale screening of ASD risk/causative genes and verified that this mutation created a new splicing donor site in the intron 1, and consequently, a decrease of WNT1 expression. Interestingly, humanized rat models harboring this mutation exhibited robust ASD-like behaviors including impaired ultrasonic vocalization (USV), decreased social interactions, and restricted and repetitive behaviors. Moreover, in the substantia nigra compacta (SNpc) and the ventral tegmental area (VTA) of mutant rats, dopaminergic (DAergic) neurons were dramatically lost, together with a comparable decrease in striatal DAergic fibers. Furthermore, using single-cell RNA sequencing, we demonstrated that the decreased DAergic neurons in these midbrain areas might attribute to a shift of the boundary of the local pool of progenitor cells from the hypothalamic floor plate to the midbrain floor plate during the early embryonic stage. Moreover, treatments of mutant rats with levodopa could attenuate the impaired USV and social interactions almost completely, but not the restricted and repetitive behaviors. Our results for the first time documented that the developmental loss of DAergic neurons in the midbrain underlies the pathogenesis of ASD, and that the abnormal progenitor cell patterning is a cellular underpinning for this developmental DAergic neuronal loss. Importantly, the effective dopamine therapy suggests a translational significance in the treatment of ASD.


Assuntos
Transtorno do Espectro Autista , Neurônios Dopaminérgicos , Animais , Ratos , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Íntrons , Mesencéfalo/metabolismo , Substância Negra/metabolismo , Área Tegmentar Ventral/metabolismo
5.
Langmuir ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329721

RESUMO

The coexistence of lead, zinc, and copper ions in wastewater constitutes an environmental challenge of pressing concern. This research delves into the preparation of innovative oxidation-doped conjugated microporous poly(aniline) frameworks, exploring their prospective efficacy in regulating lead ion adsorption from aqueous solutions. H2SO4-CMPTA demonstrates the capability to reach adsorption equilibrium within 15 min at a lead concentration of 50 ppm. Even at a lead concentration of 20 ppm, it still efficaciously attenuates these levels to sub-10 ppb, a value surpassing extant standard. H2SO4-CMPTA retains over 78.8% adsorption efficiency after six cycles. Analytical characterization coupled with computational calculations suggests that sulfate-coordinated nitrogen cationic structure plays a crucial role in adsorption. A deeper investigation reveals the cardinal role of electrostatic attraction and exclusive chelation adsorption underpinning the efficient capture of lead ions by doped sulfate ions. Intriguingly, in a mixed heavy metal solution containing lead, zinc, and copper ions, H2SO4-CMPTA exhibits an initial predilection toward zinc ions, yet an eventual ion-exchange adsorption gravitating toward lead ions was discerned, governed by the latter's superior binding energy. Our study elucidates a promising material as an efficacious tool for the remediation of aquatic environments tainted with lead contaminants.

6.
Nano Lett ; 23(6): 2121-2128, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36877932

RESUMO

Two-dimensional (2D) van der Waals heterostructures (VDWHs) containing a charge-density wave (CDW) and superconductivity (SC) have revealed rich tunability in their properties, which provide a new route for optimizing their novel exotic states. The interaction between SC and CDW is critical to its properties; however, understanding this interaction within VDWHs is very limited. A comprehensive in situ study and theoretical calculation on bulk 4Hb-TaSe2 VDWHs consisting of alternately stacking 1T-TaSe2 and 1H-TaSe2 monolayers are investigated under high pressure. Surprisingly, the superconductivity competes with the intralayer and adjacent-layer CDW order in 4Hb-TaSe2, which results in substantially and continually boosted superconductivity under compression. Upon total suppression of the CDW, the superconductivity in the individual layers responds differently to the charge transfer. Our results provide an excellent method to efficiently tune the interplay between SC and CDW in VDWHs and a new avenue for designing materials with tailored properties.

7.
Neurobiol Dis ; 180: 106105, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36977454

RESUMO

Parkinson's disease (PD) is the most common neurodegenerative movement disorder, characterized by the progressive loss of nigrostriatal dopaminergic neurons (DANs), involving the dysregulation of both neurons and glial cells. Cell type- and region-specific gene expression profiles can provide an effective source for revealing the mechanisms of PD. In this study, we adopted the RiboTag approach to obtain cell type (DAN, microglia, astrocytes)- and brain region (substantia nigra, caudate-putamen)-specific translatomes at an early stage in an MPTP-induced mouse model of PD. Through DAN-specific translatome analysis, the glycosphingolipid biosynthetic process was identified as a significantly downregulated pathway in the MPTP-treated mice. ST8Sia6, a key downregulated gene related to glycosphingolipid biosynthesis, was confirmed to be downregulated in nigral DANs from postmortem brains of patients with PD. Specific expression of ST8Sia6 in DANs exerts anti-inflammatory and neuroprotective effects in MPTP-treated mice. Through cell type (microglia vs. astrocyte) and brain region (substantia nigra vs. caudate-putamen) comparisons, nigral microglia showed the most intense immune responses. Microglia and astrocytes in the substantia nigra showed similar levels of activation in interferon-related pathways and interferon gamma (IFNG) was identified as the top upstream regulator in both cell types. This work highlights that the glycosphingolipid metabolism pathway in the DAN is involved in neuroinflammation and neurodegeneration in an MPTP mouse model of PD and provides a new data source for elucidating the pathogenesis of PD.


Assuntos
Intoxicação por MPTP , Doenças Neurodegenerativas , Fármacos Neuroprotetores , Doença de Parkinson , Camundongos , Animais , Doença de Parkinson/metabolismo , Microglia/metabolismo , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/farmacologia , Glicoesfingolipídeos/metabolismo , Camundongos Endogâmicos C57BL , Neurônios Dopaminérgicos/metabolismo , Modelos Animais de Doenças , Substância Negra/metabolismo , Intoxicação por MPTP/patologia
8.
Apoptosis ; 28(7-8): 1216-1225, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37219677

RESUMO

To investigate the role of SLITRK6 in lung adenocarcinoma (LUAD) and the underlying mechanism in it, clinical tissues and tissue microarray of LUAD were used to detect the expression of SLITRK6. In vitro cell viability assay and colony formation assay in LUAD cells were conducted to investigate SLITRK6 related biological functions. In vivo subcutaneous model was used to determine the role of SLITRK6 in LUAD growth. It was found that the expression of SLITRK6 was significantly upregulated in LUAD tissues compared with that in para-cancerous tissues. Knockdown of SLITRK6 suppressed the proliferation and colony formation of LUAD cells in vitro. Meanwhile, the growth of LUAD cells was also inhibited by SLITRK6 knockdown in vivo. Furthermore, we found that SLITRK6 knockdown could suppress the glycolysis of LUAD cells by regulating the phosphorylation of AKT and mTOR. All results suggest that SLITRK6 promotes LUAD cell proliferation and colony formation by regulating PI3K/AKT/mTOR signaling and Warburg effect. SLITRK6 may serve as a potential therapeutic target for LUAD in future.


Assuntos
Adenocarcinoma de Pulmão , Adenocarcinoma , Neoplasias Pulmonares , Humanos , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Efeito Warburg em Oncologia
9.
J Neuroinflammation ; 20(1): 203, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37674228

RESUMO

Astrocytes contribute to chronic neuroinflammation in a variety of neurodegenerative diseases, including Parkinson's disease (PD), the most common movement disorder. However, the precise role of astrocytes in neuroinflammation remains incompletely understood. Herein, we show that regulator of G-protein signaling 5 (RGS5) promotes neurodegenerative process through augmenting astrocytic tumor necrosis factor receptor (TNFR) signaling. We found that selective ablation of Rgs5 in astrocytes caused an inhibition in the production of cytokines resulting in mitigated neuroinflammatory response and neuronal survival in animal models of PD, whereas overexpression of Rgs5 had the opposite effects. Mechanistically, RGS5 switched astrocytes from neuroprotective to pro-inflammatory property via binding to the receptor TNFR2. RGS5 also augmented TNFR signaling-mediated pro-inflammatory response by interacting with the receptor TNFR1. Moreover, interrupting RGS5/TNFR interaction by either RGS5 aa 1-108 or small molecular compounds feshurin and butein, suppressed astrocytic cytokine production. We showed that the transcription of astrocytic RGS5 was controlled by transcription factor early B cell factor 1 whose expression was reciprocally influenced by RGS5-modulated TNF signaling. Thus, our study indicates that beyond its traditional role in G-protein coupled receptor signaling, astrocytic RGS5 is a key modulator of TNF signaling circuit with resultant activation of astrocytes thereby contributing to chronic neuroinflammation. Blockade of the astrocytic RGS5/TNFR interaction is a potential therapeutic strategy for neuroinflammation-associated neurodegenerative diseases.


Assuntos
Doenças Neuroinflamatórias , Proteínas RGS , Animais , Astrócitos , Transdução de Sinais , Proteínas RGS/genética , Inflamação
10.
Small ; 19(48): e2303781, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37544919

RESUMO

The energy density of lithium-sulfurized polyacrylonitrile (Li-SPAN) batteries has chronically suffered from low sulfur content. Although a free-standing electrode can significantly reduce noncapacity mass contribution, the slow bulk reaction kinetics still constrain the electrochemical performance. In this regard, a novel electrochemically active additive, polypyrrole (PPy), is introduced to construct PAN nanotubes as a sulfur carrier. This hollow channel greatly facilitates charge transport within the electrode and increases the sulfur content. Both electrochemical tests and simulations show that the SPANPPy-1% cathode possesses a larger lithium-ion diffusion coefficient and a more homogeneous phase interface than the SPAN cathode. Consequently, significantly improved capabilities and rate properties are achieved, as well as decent exportations under high-sulfur-loading or lean-electrolyte conditions. In-situ and semi-situ characterizations are further performed to demonstrate the nucleation growth of lithium sulfide and the evolution of the electrode surface structure. This type of electrochemically active additive provides a well-supported implementation of high-energy-density Li-S batteries.

11.
Small ; 19(7): e2203838, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36511178

RESUMO

To solve surface carrier recombination and sluggish water oxidation kinetics of hematite (α-Fe2 O3 ) photoanodes, herein, an attractive surface modification strategy is developed to successively deposit ultrathin CoOx overlayer and Ni single atoms on titanium (Ti)-doped α-Fe2 O3 (Ti:Fe2 O3 ) nanorods through a two-step atomic layer deposition (ALD) and photodeposition process. The collaborative decoration of ultrathin CoOx overlayer and Ni single atoms can trigger a big boost in photo-electrochemical (PEC) performance for water splitting over the obtained Ti:Fe2 O3 /CoOx /Ni photoanode, with the photocurrent density reaching 1.05 mA cm-2 at 1.23 V vs. reversible hydrogen electrode (RHE), more than three times that of Ti:Fe2 O3 (0.326 mA cm-2 ). Electrochemical and electronic investigations reveal that the surface passivation effect of ultrathin CoOx overlayer can reduce surface carrier recombination, while the catalysis effect of Ni single atoms can accelerate water oxidation kinetics. Moreover, theoretical calculations evidence that the synergy of ultrathin CoOx overlayer and Ni single atoms can lower the adsorption free energy of OH* intermediates and relieve the potential-determining step (PDS) for oxygen evolution reaction (OER). This work provides an exemplary modification through rational engineering of surface electrochemical and electronic properties for the improved PEC performances, which can be applied in other metal oxide semiconductors as well.

12.
Opt Express ; 31(22): 35453-35470, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-38017715

RESUMO

X-ray grazing incidence microscopy has extensive applications in the fields of laser inertial confinement fusion and synchrotron radiation. Monte Carlo methods can be used to determine the optical performance of X-ray grazing incidence microscopes and predict the experimental results, which is of great significance for studying physical experiments and diagnostics. In this paper, we proposed a Monte Carlo method based on Geant4 for studying X-ray grazing incidence microscopy. We introduced the G4MultilayerReflection class to describe the physical processes of X-ray multilayer mirrors. We designed a dual-energy Kirkpatrick-Baez microscope that can operate at 6.4 and 9.67 keV simultaneously. Monte Carlo simulations of the spatial resolution and throughput efficiency of the microscope were performed using Geant4, which was assembled and characterized. The spatial resolution results obtained by the Geant4 laboratory simulations, the theoretical model, and the experiments were in good agreement. Additionally, we conducted throughput efficiency calibration experiments for the 6.4 keV imaging channel. The difference between the experimental and Geant4-simulated throughput efficiency was evaluated and resulted in root mean square error values of 8.7% and 9.5% along the Y- and Z-axes, respectively.

13.
Molecules ; 28(21)2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37959780

RESUMO

In the ZINC20 database, with the aid of maximum substructure searches, common substructures were obtained from molecules with high-strain-energy and combustion heat values, and further provided domain knowledge on how to design high-energy-density hydrocarbon (HEDH) fuels. Notably, quadricyclane and syntin could be topologically assembled through these substructures, and the corresponding assembled schemes guided the design of 20 fuel molecules (ZD-1 to ZD-20). The fuel properties of the molecules were evaluated by using group-contribution methods and density functional theory (DFT) calculations, where ZD-6 stood out due to the high volumetric net heat of combustion, high specific impulse, low melting point, and acceptable flash point. Based on the neural network model for evaluating the synthetic complexity (SCScore), the estimated value of ZD-6 was close to that of syntin, indicating that the synthetic complexity of ZD-6 was comparable to that of syntin. This work not only provides ZD-6 as a potential HEDH fuel, but also illustrates the superiority of learning design strategies from the data in increasing the understanding of structure and performance relationships and accelerating the development of novel HEDH fuels.

14.
Angew Chem Int Ed Engl ; 62(19): e202217369, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36916416

RESUMO

Electrochemical CO2 reduction reaction (ECO2 RR) with controlled product selectivity is realized on Ag-Cu bimetallic surface alloys, with high selectivity towards C2 hydrocarbons/alcohols (≈60 % faradaic efficiency, FE), C1 hydrocarbons/alcohols (≈41 % FE) and CO (≈74 % FE) achieved by tuning surface compositions and applied potentials. In situ spectral investigations and theoretical calculations reveal that surface-composition-dependent d-band center could tune *CO binding strengths, regulating the *CO subsequent reaction pathways and then the product selectivity. Further adjusting the applied potentials will alter the energy of participated electrons, which leads to controlled ECO2 RR selectivity towards desired products. A predominant region map, with an indicator proposed to evaluate the thermodynamic predominance of the *CO subsequent reactions, is then provided as a reliable theoretical guidance for the controllable ECO2 RR product selectivity over bimetallic alloys.

15.
Angew Chem Int Ed Engl ; 62(12): e202214880, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36545843

RESUMO

Ni-rich layered oxides are one of the most attractive cathode materials in high-energy-density lithium-ion batteries, their degradation mechanisms are still not completely elucidated. Herein, we report a strong dependence of degradation pathways on the long-range cationic disordering of Co-free Ni-rich Li1-m (Ni0.94 Al0.06 )1+m O2 (NA). Interestingly, a disordered layered phase with lattice mismatch can be easily formed in the near-surface region of NA particles with very low cation disorder (NA-LCD, m≤0.06) over electrochemical cycling, while the layered structure is basically maintained in the core of particles forming a "core-shell" structure. Such surface reconstruction triggers a rapid capacity decay during the first 100 cycles between 2.7 and 4.3 V at 1 C or 3 C. On the contrary, the local lattice distortions are gradually accumulated throughout the whole NA particles with higher degrees of cation disorder (NA-HCD, 0.06≤m≤0.15) that lead to a slow capacity decay upon cycling.

16.
Opt Express ; 30(15): 26761-26773, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-36236862

RESUMO

High-resolution X-ray imaging diagnosis is a critical method for measuring Rayleigh-Taylor instability growth and hot spot interface morphology in inertial confinement fusion experiments. In this study, we develop a quasi-monochromatic elliptical Kirkpatrick-Baez microscope based on aberration theory, breaking the aberration limit of conventional Kirkpatrick-Baez microscopes. The microscope was characterized in the laboratory for spatial resolution performance and modulation transfer function before being implemented in cavity experiments at the SG-III prototype laser facility. The results demonstrate that the edge-based method achieves a spatial resolution of <2 µm in the central field of view and modulation of 800 lp/mm spatial frequency of >20%.

17.
Opt Express ; 30(6): 8777-8793, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299323

RESUMO

The measurement of hotspot electron temperature is a paramount technique of implosion physics research in inertial confinement fusion. This study proposes a novel quasi-coaxis dual-energy flat spectral response high-resolution X-ray imaging instrument comprising a dual-channel total-reflection Kirkpatrick-Baez microscope and two flat non-periodic multilayer mirrors, which can image at 6.4 ± 0.5 and 9.67 ± 0.5 keV simultaneously. Various theoretical simulations were performed to verify the performance and feasibility of the imaging instrument, which was assembled and characterized in a laboratory. Experimental results show that the imaging instrument could achieve a high spatial resolution of 5 µm in a ± 150 µm field of view (FOV), the root mean square(RMS) deviation values of the measured reflection efficiency are 1.71% and 1.82% for the 6.4 keV and 9.67 keV imaging channels, respectively, in the ± 150 µm FOV.

18.
Langmuir ; 38(26): 7965-7975, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35731623

RESUMO

Gels prepared with the solvent-triggering method are attractive for their easy and fast preparation; however, the role of solvents in this process remains unclear, which hinders the efficient and accurate control of desired gel properties. In this study, the role of solvents in the solvent-triggering gelation process is studied using 9-fluorenylmethoxycarbonyl (Fmoc)-protected diphenylalanine (Fmoc-FF) as the gelator. Density functional theory (DFT)-based calculations and corresponding wavefunction analyses are conducted to identify the H-bonding interaction sites between the molecules. The calculation results clearly annotate the activating role of DMF and the triggering role of H2O in the gelation process. The solvation of Fmoc-FF by DMF can activate the H-bonding sites on the peptide chain, showing a conformation reversal and higher electrostatic potentials. Then, the H-bonding between Fmoc-FF and H2O is facilitated to trigger gelation. The physical Fmoc-FF/DMF/H2O gels show easily tuned mechanical strengths (G' of 102-105 Pa), injectable potentials (general yield strain < 100%), and stable recoverability (80-98% within 100 s). The regulation of these properties depends on not only the gelator concentration but also the H-bonding interactions with solvent molecules, which have seldom been studied in detail before. By understanding the effect of solvents, low-molecular-weight gelator-based gels can be designed, prepared, and tuned efficiently for potential applications.


Assuntos
Fenilalanina , Géis/química , Conformação Molecular , Fenilalanina/química , Solventes/química
19.
Org Biomol Chem ; 20(20): 4081-4085, 2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35521652

RESUMO

Herein, we report a catalyst-free 'click' reaction: metal-free [2 + 2] cycloaddition-retro-electrocyclisation (CA-RE) of arylynamines with the sluggish acceptor tetracyanoquinodimethane (TCNQ) to provide orthogonal electron-push-pull light-harvesting small molecules: N-heterocyclic dicyanoquinodimethane-substituted methylene malononitriles. Ynamines are reactive alkynes and tend to induce over-reactions with the CA-RE adducts. The reactivity of arylynamines was balanced properly by ensuring the electron-density of the nitrogen atom was delocalised more over the aromatic rings than the triple bond.


Assuntos
Alcinos , Elétrons , Alcinos/química , Catálise , Reação de Cicloadição
20.
BMC Vet Res ; 18(1): 416, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36447208

RESUMO

BACKGROUND: Pasteurella multocida (P. multocida) infection can cause a series of diseases in different animals and cause huge economic losses to the breeding industry. P. multocida is considered to be one of the most significant pathogens in rabbits. In order to elucidate the pathogenic mechanism and innate immune response of P. multocida, an infection experiment was carried out in this study. RESULTS: Our results showed that the clinical symptoms of rabbits were severe dyspnoea and serous nasal fluid. During the course of the disease, the deaths peaked at 2 days post infection (dpi) and mortality rate was 60%. The pathological changes of the lung, trachea, and thymus were observed. In particular, consolidation and abscesses appeared in lung. Histopathologic changes in rabbits showed edema, hemorrhage, and neutrophil infiltration in the lung. P. multocida can rapidly replicate in a variety of tissues, and the colonization in most of the tested tissues reached the maximum at 2 dpi and then decreased at 3 dpi. The number of P. multocida in lung and thymus remained high level at 3 dpi. Toll-like receptors 2 and 4 signaling pathways were activated after P. multocida infection. The expression of Il1ß, Il6, Il8, and Tnf-α was significantly increased. The expression of most proinflammatory cytokines peaked at 2 dpi and decreased at 3 dpi, and the expression trend of cytokines was consistent with the colonization of P. multocida in rabbit tissues. CONCLUSIONS: The P. multocida can rapidly replicate in various tissues of rabbit and cause bacteremia after infection. TLRs signaling pathways were activated after P. multocida infection, significantly inducing the expression of proinflammatory cytokines, which is might the main cause of respiratory inflammation and septicemia.


Assuntos
Lagomorpha , Infecções por Pasteurella , Pasteurella multocida , Animais , Coelhos , Virulência , Infecções por Pasteurella/veterinária , Imunidade Inata , Citocinas
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