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1.
Small ; : e2402863, 2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38764314

RESUMEN

Facing the increasing global shortage of freshwater resources, this study presents a suspended multilayer evaporator (SMLE), designed to tackle the principal issues plaguing current solar-driven interfacial evaporation technologies, specifically, substantial thermal losses and limited water production. This approach, through the implementation of a multilayer structural design, enables superior thermal regulation throughout the evaporation process. This evaporator consists of a radiation damping layer, a photothermal conversion layer, and a bottom layer that leverages radiation, wherein the bottom layer exhibits a notable infrared emissivity. The distinctive feature of the design effectively reduces radiative heat loss and facilitates dual-interface evaporation by heating the water surface through mid-infrared radiation. The refined design leads to a notable evaporation rate of 2.83 kg m-2 h-1. Numerical simulations and practical performance evaluations validate the effectiveness of the multilayer evaporator in actual use scenarios. This energy-recycling and dual-interface evaporation multilayered approach propels the design of high-efficiency solar-driven interfacial evaporators forward, presenting new insights into developing effective water-energy transformation systems.

2.
Small ; 20(2): e2305473, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37688298

RESUMEN

Traditional nonlinear optical (NLO) crystals are exclusively limited to ionic crystals with π-conjugated groups and it is a great challenge to achieve a subtle balance between second-harmonic generation, bandgap, and birefringence for them, especially in the deep-UV spectrum region (Eg  > 6.20 eV). Herein, a non-π-conjugated molecular crystal, NH3 BH3 , which realizes such balance with a large second-harmonic generation response (2.0 × KH2 PO4 at 1064 nm, and 0.45 × ß-BaB2 O4 at 532 nm), deep-UV transparency (Eg > 6.53 eV), and moderate birefringence (Δn = 0.056@550 nm) is reported. As a result, NH3 BH3 exhibits a large quality factor of 0.32, which is evidently larger than those of non-π-conjugated sulfate and phosphate ionic crystals. Using an unpolished NH3 BH3 crystal, effective second-harmonic generation outputs are observed at different wavelengths. These attributes indicate that NH3 BH3 is a promising candidate for deep-UV NLO applications. This work opens up a new door for developing high-performance deep-UV NLO crystals.

3.
Biol Reprod ; 110(5): 895-907, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38267362

RESUMEN

It is known that the oocyte has a limited capacity to acquire and metabolize glucose, and it must rely on cumulus cells (CCs) to take up glucose and produce pyruvate for use to produce ATP through oxidative phosphorylation. We therefore propose that miRNAs might regulate glucose metabolism (GM) in CCs and might be used as markers for oocyte quality assessment. Here, mouse CC models with impaired glycolysis or pentose phosphate pathway (PPP) were established, and miRNAs targeting the key enzymes in glycolysis/PPP were predicted using the miRNA target prediction databases. Expression of the predicted miRNAs was compared between CCs with normal and impaired glycolysis/PPP to identify candidate miRNAs. Function of the candidate miRNAs was validated by transfecting CCs or cumulus-oocyte-complexes (COCs) with miRNA inhibitors and observing effects on glucose metabolites of CCs and on competence of oocytes. The results validated that miR-23b-3p, let-7b-5p, 34b-5p and 145a-5p inhibited glycolysis, and miR-24-3p, 3078-3p,183-5p and 7001-5p inhibited PPP of CCs. Our observation using a more physiologically relevant model (intact cultured COCs) further validated the four glycolysis-targeting miRNAs we identified. Furthermore, miR-let-7b-5p, 34b-5p and 145a-5p may also inhibit PPP, as they decreased the production of glucose-6-phosphate. In conclusion, miRNAs play critical roles in GM of CCs and may be used as markers for oocyte quality assessment. Summary sentence:  We identified and validated eight new miRNAs that inhibit glycolysis and/or pentose phosphate pathways in cumulus cells (CCs) suggesting that miRNAs play critical roles in glucose metabolism of CCs and may be used for oocyte quality markers.


Asunto(s)
Células del Cúmulo , Glucosa , Glucólisis , MicroARNs , Animales , Células del Cúmulo/metabolismo , MicroARNs/metabolismo , MicroARNs/genética , Ratones , Glucosa/metabolismo , Femenino , Glucólisis/fisiología , Vía de Pentosa Fosfato , Oocitos/metabolismo
4.
J Exp Bot ; 75(5): 1314-1330, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38069660

RESUMEN

Sphingolipids are membrane lipids and play critical roles in signal transduction. Ceramides are central components of sphingolipid metabolism that are involved in cell death. However, the mechanism of ceramides regulating cell death in plants remains unclear. Here, we found that ceramides accumulated in mitochondria of accelerated cell death 5 mutant (acd5), and expression of mitochondrion-localized ceramide kinase (ACD5) suppressed mitochondrial ceramide accumulation and the acd5 cell death phenotype. Using immuno-electron microscopy, we observed hyperaccumulation of ceramides in acer acd5 double mutants, which are characterized by mutations in both ACER (alkaline ceramidase) and ACD5 genes. The results confirmed that plants with specific ceramide accumulation exhibited localization of ceramides to mitochondria, resulting in an increase in mitochondrial reactive oxygen species production. Interestingly, when compared with the wild type, autophagy-deficient mutants showed stronger resistance to ceramide-induced cell death. Lipid profiling analysis demonstrated that plants with ceramide accumulation exhibited a significant increase in phosphatidylethanolamine levels. Furthermore, exogenous ceramide treatment or endogenous ceramide accumulation induces autophagy. When exposed to exogenous ceramides, an increase in the level of the autophagy-specific ubiquitin-like protein, ATG8e, associated with mitochondria, where it directly bound to ceramides. Taken together, we propose that the accumulation of ceramides in mitochondria can induce cell death by regulating autophagy.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ceramidas/metabolismo , Ceramidas/farmacología , Arabidopsis/metabolismo , Mitocondrias/metabolismo , Autofagia , Muerte Celular , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
5.
Inorg Chem ; 63(9): 4412-4418, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38381086

RESUMEN

Due to the flexible structural tunability and excellent photoelectric performance, hybrid organic-inorganic metal halides (OIMHs) have attracted intensive attention and become a hot topic in the field of materials. It is important and necessary to explore new OIMHs and study their structure-property relationship. In this work, a new lead-free OIMH, (C5N2H14Cl)GeCl3, is synthesized by the combination of hydrothermal and solution methods. This compound features a zero-dimensional structure composed of inorganic [GeCl3]- trigonal pyramids surrounded by isolated Cl- anions and organic (C5N2H14)2+ cations. Preliminary characterization and first-principles calculations are performed to study its basic optical properties. Interestingly, (C5N2H14Cl)GeCl3 shows weak blue emission under ultraviolet excitation, and the intrinsic mechanism is discussed.

6.
Clin Radiol ; 79(3): e453-e461, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38160104

RESUMEN

AIM: To establish an artificial neural network (ANN) model to predict subsolid nodules (SSNs) before percutaneous core-needle biopsy (PCNB). The results of the two methods were compared to provide guidance on the treatment of SSNs. MATERIALS AND METHODS: This was a single-centre retrospective study using data from 1,459 SSNs between 2013 and 2021. The ANN was developed using data from patients who underwent surgery following computed tomography (CT) (SFC) and validated using data from patients who underwent surgery following biopsy (SFB). The prediction results of the ANN for the PCNB group and the histopathological results obtained after biopsy were compared with the histopathological results of lung nodules in the same group after surgery. Additionally, the choice of predictors for PCNB was analysed using multivariate analysis. RESULTS: There was no significant difference between the accuracies of the ANN and PCNB in the SFB group (p=0.086). The sensitivity of PCNB was lower than that of the ANN (p=0.000), but the specificity was higher (p=0.001). PCNB had better diagnostic ability than the ANN. The incidence of precursor lesions and non-neoplastic lesions in the SFB group was lower than that in the SFC group (p=0.000). A history of malignant tumours, size (2-3 cm), volume (>400 cm3) and mean CT value (≥-450 HU) are important factors for selecting PCNB. CONCLUSIONS: Both ANN and PCNB have comparable accuracy in diagnosing SSNs; however, PCNB has a slightly higher diagnostic ability than ANN. Selecting appropriate patients for PCNB is important for maximising the benefit to SSN patients.


Asunto(s)
Neoplasias Pulmonares , Nitrobencenos , Tomografía Computarizada por Rayos X , Humanos , Estudios Retrospectivos , Biopsia , Biopsia con Aguja Gruesa , Tomografía Computarizada por Rayos X/métodos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología
7.
Biochem Genet ; 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684626

RESUMEN

Hepatocellular carcinoma (HCC) is a significant cancer with limited treatments and a poor prognosis, with the basement membrane (BM) playing a crucial role in its initiation and growth. This study utilized data from The Cancer Genome Atlas and the Gene Expression Omnibus (GEO) databases to identify basement membrane-related genes differentially expressed in HCC. Through gene co-expression analysis, BM-associated long non-coding RNAs (lncRNAs) were discovered. LncRNAs related to HCC survival were selected via univariate analysis, and a prognostic model was constructed using LASSO regression and multivariate analysis. This model effectively classified HCC patients into high and low-risk groups, uncovering significant differences in prognosis, immune response, mutation, and drug sensitivity. Six BM-related lncRNAs (GSEC, MIR4435-2HG, AC092614.1, AC127521.1, LINC02580, and AC008050.1) were validated in normal and HCC cell lines, and the key role of AC092614.1 in regulating proliferation, migration, and invasion of HCC cells in vitro was explored. This research emphasizes the prognostic and therapeutic relevance of BM-related lncRNAs in HCC, highlighting AC092614.1's role in disease progression and as a potential target for targeted therapy.

8.
Small ; : e2307754, 2023 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-38072773

RESUMEN

In this work, a novel high entropy hydroxide NiCoMoMnZn-layered double hydroxide(LDH) is synthesized as an electrode material for supercapacitors using a novel template re-etching method to promote the energy density. As a positive electrode material for supercapacitors, NiCoMoMnZn-LDH has the advantage of a uniform distribution of elements, high specific surface area, porous and stable structure. More importantly, the specific capacitance can reach 1810.2 F g-1 at the current density of 0.5 A g-1 , and the NiCoMoMnZn-LDH//AC HSC assembled from the material has an energy density of up to 62.1 Wh kg-1 at a power density of 475 W kg-1 . Moreover, the influence of different compositions on their morphological, structural, and electrochemical properties is investigated based on the characterization results. Then, the synergistic mechanism among the components of the high entropy NiCoMoMnZn-LDH is revealed in detail by DFT calculations. In addition, the synthesis strategy proposed in this work for high-entropy hydroxides exhibits universality. Experimental results show that the proposed strategy successfully avoids not only phase separation and element aggregation in the formation of high entropy materials, but also reduces structural distortion, which is beneficial for efficient and large-scale synthesis of high entropy hydroxides.

9.
J Transl Med ; 21(1): 73, 2023 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-36737759

RESUMEN

BACKGROUND: The correlation and difference in T-cell phenotypes between peripheral blood lymphocytes (PBLs) and the tumor immune microenvironment (TIME) in patients with gastric cancer (GC) is not clear. We aimed to characterize the phenotypes of CD8+ T cells in tumor infiltrating lymphocytes (TILs) and PBLs in patients with different outcomes and to establish a useful survival prediction model. METHODS: Multiplex immunofluorescence staining and flow cytometry were used to detect the expression of inhibitory molecules (IMs) and active markers (AMs) in CD8+TILs and PBLs, respectively. The role of these parameters in the 3-year prognosis was assessed by receiver operating characteristic analysis. Then, we divided patients into two TIME clusters (TIME-A/B) and two PBL clusters (PBL-A/B) by unsupervised hierarchical clustering based on the results of multivariate analysis, and used the Kaplan-Meier method to analyze the difference in prognosis between each group. Finally, we constructed and compared three survival prediction models based on Cox regression analysis, and further validated the efficiency and accuracy in the internal and external cohorts. RESULTS: The percentage of PD-1+CD8+TILs, TIM-3+CD8+TILs, PD-L1+CD8+TILs, and PD-L1+CD8+PBLs and the density of PD-L1+CD8+TILs were independent risk factors, while the percentage of TIM-3+CD8+PBLs was an independent protective factor. The patients in the TIME-B group showed a worse 3-year overall survival (OS) (HR: 3.256, 95% CI 1.318-8.043, P = 0.006), with a higher density of PD-L1+CD8+TILs (P < 0.001) and percentage of PD-1+CD8+TILs (P = 0.017) and PD-L1+CD8+TILs (P < 0.001) compared to the TIME-A group. The patients in the PBL-B group showed higher positivity for PD-L1+CD8+PBLs (P = 0.042), LAG-3+CD8+PBLs (P < 0.001), TIM-3+CD8+PBLs (P = 0.003), PD-L1+CD4+PBLs (P = 0.001), and LAG-3+CD4+PBLs (P < 0.001) and poorer 3-year OS (HR: 0.124, 95% CI 0.017-0.929, P = 0.015) than those in the PBL-A group. In our three survival prediction models, Model 3, which was based on the percentage of TIM-3+CD8+PBLs, PD-L1+CD8+TILs and PD-1+CD8+TILs, showed the best sensitivity (0.950, 0.914), specificity (0.852, 0.857) and accuracy (κ = 0.787, P < 0.001; κ = 0.771, P < 0.001) in the internal and external cohorts, respectively. CONCLUSION: We established a comprehensive and robust survival prediction model based on the T-cell phenotype in the TIME and PBLs for GC prognosis.


Asunto(s)
Linfocitos T CD8-positivos , Neoplasias Gástricas , Humanos , Antígeno B7-H1/metabolismo , Receptor 2 Celular del Virus de la Hepatitis A/metabolismo , Neoplasias Gástricas/patología , Receptor de Muerte Celular Programada 1/metabolismo , Pronóstico , Linfocitos Infiltrantes de Tumor , Microambiente Tumoral
10.
Opt Express ; 31(23): 37703-37721, 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-38017895

RESUMEN

Sensitivity to weather conditions is the principal limitation of free-space optical communication. However, for the scattering based ultraviolet (UV) non-line-of-sight (NLOS) communication, the atmospheric scattering effect functions as an attenuation factor and potentially as a performance enhancer. To investigate the UV NLOS transmission coverage under different weather conditions, we employ the Mie Theory in conjunction with classical aerosol and hydrometeor particle models to estimate the absorption coefficient, the scattering coefficient, and the scattering phase function. We then use these atmospheric parameters combined with a range estimation model to determine the coverage of the UV NLOS communication for specified path loss. Simulation results reveal that in non-precipitating weather, poorer visibility correlates with broader coverage. In foggy conditions, the coverage range in light fog exceeds that in fog-free environments; however, as fog intensity increases, the coverage range decreases. Rain enhances the coverage range; and heavier precipitation results in a larger coverage area.

11.
Opt Express ; 31(20): 33435-33448, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37859126

RESUMEN

Due to a great many superior features of infrared light communication (ILC), like high capacity and strong privacy, ILC is considered a potential candidate for serving the high demands of beyond fifth-generation/sixth-generation (B5G/6 G) communication systems. However, the terminal's limited field-of-view (FOV) induces great difficulty in establishing line-of-sight (LoS) link between the transceiver and the terminal. In this paper, we propose a wide-FOV auto-coupling optical antenna system that utilizes a wide-FOV telecentric lens to collect incident infrared beams and automatically couple them into a specific single-mode-fiber (SMF) channel of fiber array and optical switch. The performance of this optical antenna system is assessed through simulation and manual alignment operation, and validated by automatic alignment results. A coupling loss of less than 10.6 dB within a FOV of 100° for both downstream and upstream beams in C band is demonstrated by the designed system. Furthermore, we establish a bidirectional optical wireless communications (OWC) system employing this antenna and a fiber-type modulating retro-reflector (MRR) system in the terminal. Both 10-Gbps on-off keying (OOK) downstream and upstream transmissions are successfully realized with the FOV of up to 100° in C band where the measured bit-error-rate (BER) is lower than 3.8 × 10-3. To the best of our knowledge, this is a brand-new auto-coupling optical antenna system with the largest FOV in ILC automatic alignment works in terminals that have ever been reported.

12.
Anal Biochem ; 676: 115234, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37422060

RESUMEN

Abnormal expression of carcinoembryonic antigen (CEA) can be used for early diagnosis of various cancers (e.g. colorectal cancer, cervical carcinomas, and breast cancer). In this work, using l-cysteine-ferrocene-ruthenium nanocomposites (L-Cys-Fc-Ru) to immobilize secondary antibody (Ab2) and Au nanoparticles (NPs) as the substrate to ensure accurate capture of primary antibody (Ab1), a signal-on sandwich-like biosensor was constructed in the presence of CEA. Specifically, Ru nanoassemblies (NAs) were first prepared by a facile one-step solvothermal approach as signal amplifiers for the electrical signal of Fc. Based on specific immune recognition, as the increase of CEA concentration, the content of L-Cys-Fc-Ru-Ab2 captured on the electrode surface also increased, thus the signal of Fc gradually increased. Therefore, the quantitative detection of CEA can be realized according to the peak current of Fc. After a series of experiments, it was found that the biosensor has a wide detection range from 1.0 pg mL-1 to 100.0 ng mL-1 and a low detection limit down to 0.5 pg mL-1, as well as good selectivity, repeatability and stability. Furthermore, satisfactory results were also obtained for the determination of CEA in serums, which were comparable to commercial electrochemiluminescence (ECL) method. The developed biosensor shows great potential in clinical applications.


Asunto(s)
Técnicas Biosensibles , Neoplasias de la Mama , Nanopartículas del Metal , Humanos , Femenino , Antígeno Carcinoembrionario , Oro/química , Nanopartículas del Metal/química , Inmunoensayo/métodos , Técnicas Electroquímicas/métodos , Técnicas Biosensibles/métodos , Límite de Detección
13.
Inorg Chem ; 62(2): 823-829, 2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36602526

RESUMEN

Hybrid organic-inorganic metal halide (OIMH) perovskites are regarded as potential photoluminescent (PL) materials and have attracted intensive attention. Here, we select 1-methylpiperazine as an organic component and successfully obtain a two-dimensional (2D) Ge-based OIMH perovskite, (1-mpz)GeBr4. It features a 2D layered structure composed of distorted [GeBr6]4- octahedra with organic (C5H14N2)2+ located between the layers. (1-mpz)GeBr4 exhibits strong orange color under ultraviolet (UV) light and possesses good PL stability for over 2 months. The photoluminescence quantum efficiency is measured to be 7.15% at room temperature, which is the largest among all reported low-dimensional Ge-based perovskites. Experimental measurements, combined with first-principles calculations, reveal that its PL property is attributed to self-trapped excitons (STEs) from [GeBr6]4- groups. From the deduced structure-property relationship, Ge-based OIMH PL perovskites with good stability and high PL efficiency can be expected.

14.
Phys Chem Chem Phys ; 25(42): 28871-28884, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37853798

RESUMEN

The molecular mechanism of a Cu-catalysed coupling reaction was theoretically studied using density functional theory (DFT) and the complete active space self-consistent field method followed by the second-order perturbation theory (CASSCF/CASPT2) to investigate the effects of the strong electron correlation of the Cu centre on the reaction profile. Both DFT and CASSCF/CASPT2 calculations showed that the catalytic cycle proceeds via an oxidative addition (OA) reaction, followed by a reductive elimination (RE) reaction, where OA is the rate-determining step. Although the DFT-calculated activation energies of the OA and RE steps are highly dependent on the choice of functionals, the CASSCF/CASPT2 results are less affected by the choice of DFT-optimised geometries. Therefore, with a careful assessment based on the CASSCF/CASPT2 single-point energy evaluation, an optimal choice of the DFT geometry is of good qualitative use for energetics at the CASPT2 level of theory. Based on the changes in the electron populations of the 3d orbitals during the OA and RE steps, the characteristic features of the DFT-calculated electronic structure were qualitatively consistent with those calculated using the CASSCF method. Further electronic structure analysis by the natural orbital occupancy of the CASSCF wavefunction showed that the ground state is almost single-reference in this system and the strong electron correlation effect of the Cu centre can be dealt with using the MP2 or CCSD method, too. However, the slightly smaller occupation numbers of the 3dπ orbital in the course of reactions suggested that the electron correlation effect of the Cu(III) centre appears through the interaction between the 3dπ orbital and the C-I antibonding σ* orbital in the OA step, and between the 3dπ orbital and the Cu-C antibonding σ* orbital in the RE step.

15.
J Phys Chem A ; 127(8): 1975-1987, 2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36799901

RESUMEN

We develop a multireference quantum embedding model to investigate a recent experimental observation of the isomerization of vibrationally excited CO molecules on a NaCl(100) surface [Science 2020, 367, 175-178]. To explore this mechanism, we built a reduced potential energy surface of CO interacting with NaCl(100) using a second-order multireference perturbation theory, modeling the adsorbate-surface interaction with our previously developed active space embedding theory (ASET). We considered an isolated CO molecule on NaCl(100) and a high-coverage CO monolayer (1/1), and for both we generated potential energy surfaces parametrized by the CO stretching, adsorption, and inversion coordinates. These surfaces are used to determine stationary points and adsorption energies and to perform a vibrational analysis of the states relevant to the inversion mechanism. We found that for near-equilibrium bond lengths, CO adsorbed in the C-down configuration is lower in energy than in the O-down configuration. Stretching of the C-O bond reverses the energetic order of these configurations, supporting the accepted isomerization mechanism. The vibrational constants obtained from these potential energy surfaces show a small (< 10 cm-1) blue- and red-shift for the C-down and O-down configurations, respectively, in agreement with experimental assignments and previous theoretical studies. Our vibrational analysis of the monolayer case suggests that the O-down configuration is energetically more stable than the C-down one beyond the 16th vibrational excited state of CO, a value slightly smaller than the one from quasi-classical trajectory simulations (22nd) and consistent with the experiment. Our analysis suggests that CO-CO interactions in the monolayer play an important role in stabilizing highly vibrationally excited states in the O-down configuration and reducing the barrier between the C-down and O-down geometries, therefore playing a crucial role in the inversion mechanism.

16.
Entropy (Basel) ; 25(1)2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36673320

RESUMEN

Due to its simple structure and lack of moving parts, the supersonic air ejector has been widely applied in the fields of machinery, aerospace, and energy-saving. The performance of the ejector is influenced by the flow channel structure and the velocity of the jet, thus the confined jet is an important limiting factor for the performance of the supersonic air ejector. In order to investigate the effect of the confined jet on the performance of the ejector, an air ejector with a rectangular section was designed. The effects of the section width (Wc) on the entrainment ratio, velocity distribution, turbulent kinetic energy distribution, Mach number distribution, and vorticity distribution of the rectangular section air ejector were studied numerically. The numerical results indicated that the entrainment ratio of the rectangular section air ejector increased from 0.34 to 0.65 and the increment of the ER was 91.2% when the section width increased from 1 mm to 10 mm. As Wc increased, the region of the turbulent kinetic energy gradually expanded. The energy exchange between the primary fluid and the secondary fluid was mainly in the form of turbulent diffusion in the mixing chamber. In addition to Wc limiting the fluid flow in the rectangular section air ejector, the structure size of the rectangular section air ejector in the XOY plane also had a limiting effect on the internal fluid flow. In the rectangular section air ejector, the streamwise vortices played an important role in the mixing process. The increase of Wc would increase the distribution of the streamwise vortices in the constant-area section. Meanwhile, the distribution of the spanwise vortices would gradually decrease.

17.
Plant J ; 107(5): 1447-1465, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34180563

RESUMEN

Sphingolipids have key functions in plant membrane structure and signaling. Perturbations of plant sphingolipid metabolism often induce cell death and salicylic acid (SA) accumulation; SA accumulation, in turn, promotes sphingolipid metabolism and further cell death. However, the underlying molecular mechanisms remain unclear. Here, we show that the Arabidopsis thaliana lipase-like protein ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) and its partner PHYTOALEXIN DEFICIENT 4 (PAD4) participate in sphingolipid metabolism and associated cell death. The accelerated cell death 5 (acd5) mutants accumulate ceramides due to a defect in ceramide kinase and show spontaneous cell death. Loss of function of EDS1, PAD4 or SALICYLIC ACID INDUCTION DEFICIENT 2 (SID2) in the acd5 background suppressed the acd5 cell death phenotype and prevented ceramide accumulation. Treatment with the SA analogue benzothiadiazole partially restored sphingolipid accumulation in the acd5 pad4 and acd5 eds1 double mutants, showing that the inhibitory effect of the pad4-1 and eds1-2 mutations on acd5-conferred sphingolipid accumulation partly depends on SA. Moreover, the pad4-1 and eds1-2 mutations substantially rescued the susceptibility of the acd5 mutant to Botrytis cinerea. Consistent with this, B. cinerea-induced ceramide accumulation requires PAD4 or EDS1. Finally, examination of plants overexpressing the ceramide synthase gene LAG1 HOMOLOGUE2 suggested that EDS1, PAD4 and SA are involved in long-chain ceramide metabolism and ceramide-associated cell death. Collectively, our observations reveal that EDS1 and PAD4 mediate ceramide (especially long-chain ceramide) metabolism and associated cell death, by SA-dependent and SA-independent pathways.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Hidrolasas de Éster Carboxílico/metabolismo , Ceramidas/metabolismo , Proteínas de Unión al ADN/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Enfermedades de las Plantas/inmunología , Apoptosis , Arabidopsis/inmunología , Arabidopsis/fisiología , Proteínas de Arabidopsis/genética , Botrytis/fisiología , Hidrolasas de Éster Carboxílico/genética , Proteínas de Unión al ADN/genética , Susceptibilidad a Enfermedades , Perfilación de la Expresión Génica , Transferasas Intramoleculares/genética , Transferasas Intramoleculares/metabolismo , Mutación con Pérdida de Función , Mutación , Fenotipo , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Enfermedades de las Plantas/microbiología , Ácido Salicílico/metabolismo , Sesquiterpenos/metabolismo , Esfingolípidos/metabolismo , Fitoalexinas
18.
Small ; 18(49): e2204647, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36310141

RESUMEN

Liquid hydrogen carriers featuring high hydrogen content, safety, and hydrogen release on demand have motivated great endeavors for sustainable hydrogen supply. Nonetheless, direct hydrogen release is limited by the ultralow hydrogen evolution rate, while the conventional manner of extra additive and solvent addition for promoting rates greatly deteriorates its hydrogen storage density. Thus, it is still challenging to simultaneously satisfy high-performance hydrogen release and high storage density. Herein, an aerophobicity surface-based gas-liquid interface reaction strategy is proposed, which renders rapid product removal to promote dehydrogenation, fundamentally circumventing the employment of additives and solvents. Accordingly, a hierarchically porous resin-grafted reduced graphene oxide aerogel is designed. It imparts superaerophobic surface to facilitate product detachment from reactive sites, and the structure-oriented interface reaction design provides product diffusion channels and reduced diffusion resistance. As a result, the aerogel harvests a record hydrogen evolution rate (347 mmol g-1  h-1 ) in an ultrahigh-density formic acid of 19.8 g L-1 , around two times the rate promotion and ten times the density improvement compared to the state-of-the-art materials and systems. The strategy presents an approach for the dehydrogenation of liquid hydrogen carriers, e.g., formic acid, formaldehyde, and hydrazine hydrate, concurrently ensuring high-performance hydrogen release and high hydrogen storage density.


Asunto(s)
Formiatos , Hidrógeno , Difusión , Formaldehído , Solventes
19.
Plant Physiol ; 187(3): 1713-1727, 2021 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-34618068

RESUMEN

Sphingolipids are structural components of the lipid bilayer that acts as signaling molecules in many cellular processes, including cell death. Ceramides, key intermediates in sphingolipid metabolism, are phosphorylated by the ceramide kinase ACCELERATED CELL DEATH5 (ACD5). The loss of ACD5 function leads to ceramide accumulation and spontaneous cell death. Here, we report that the jasmonate (JA) pathway is activated in the Arabidopsis (Arabidopsis thaliana) acd5 mutant and that methyl JA treatment accelerates ceramide accumulation and cell death in acd5. Moreover, the double mutants of acd5 with jasmonate resistant1-1 and coronatine insensitive1-2 exhibited delayed cell death, suggesting that the JA pathway is involved in acd5-mediated cell death. Quantitative sphingolipid profiling of plants treated with methyl JA indicated that JAs influence sphingolipid metabolism by increasing the levels of ceramides and hydroxyceramides, but this pathway is dramatically attenuated by mutations affecting JA pathway proteins. Furthermore, we showed that JAs regulate the expression of genes encoding enzymes in ceramide metabolism. Together, our findings show that JAs accelerate cell death in acd5 mutants, possibly by modulating sphingolipid metabolism and increasing ceramide levels.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Muerte Celular , Ciclopentanos/farmacología , Oxilipinas/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Reguladores del Crecimiento de las Plantas/farmacología , Esfingolípidos/metabolismo , Proteínas de Arabidopsis/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo
20.
J Exp Bot ; 73(14): 4954-4967, 2022 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-35436324

RESUMEN

Plant sphingolipids are important membrane components and bioactive molecules in development and defense responses. However, the function of sphingolipids in plant defense, especially against herbivores, is not fully understood. Here, we report that Spodoptera exigua feeding affects sphingolipid metabolism in Arabidopsis, resulting in increased levels of sphingoid long-chain bases, ceramides, and hydroxyceramides. Insect-induced ceramide and hydroxyceramide accumulation is dependent on the jasmonate signaling pathway. Loss of the Arabidopsis alkaline ceramidase ACER increases ceramides and decreases long-chain base levels in plants; in this work, we found that loss of ACER enhances plant resistance to S. exigua and improves response to mechanical wounding. Moreover, acer-1 mutants exhibited more severe root-growth inhibition and higher anthocyanin accumulation than wild-type plants in response to methyl jasmonate treatment, indicating that loss of ACER increases sensitivity to jasmonate and that ACER functions in jasmonate-mediated root growth and secondary metabolism. Transcript levels of ACER were also negatively regulated by jasmonates, and this process involves the transcription factor MYC2. Thus, our findings reveal that ACER is involved in mediating jasmonate-related plant growth and defense and that jasmonates function in regulating the expression of ACER.


Asunto(s)
Acer , Proteínas de Arabidopsis , Arabidopsis , Ceramidasa Alcalina/genética , Ceramidasa Alcalina/metabolismo , Animales , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ceramidas/metabolismo , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Herbivoria , Insectos , Oxilipinas/metabolismo , Esfingolípidos/metabolismo
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