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2.
Micromachines (Basel) ; 15(5)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38793156

RESUMO

Hollow-strut metal lattice structures are currently attracting extensive attention due to their excellent mechanical performance. Inspired by the node structure of bamboo, this study aimed to investigate the mechanical performance of the gradient hollow-strut octet lattice structure fabricated by laser powder bed fusion (LPBF). The effect of geometrical parameters on the yield strength, Young's modulus and energy absorption of the designed octet unit cells were studied and optimized by FEA analysis. The hollow-strut geometrical parameters that deliver the best mechanical property combinations were identified, and the corresponding unit cells were then redesigned into the 3 × 3 × 3 type lattice structures for experimental evaluations. Compression tests confirmed that the designed gradient hollow-strut octet lattice structures demonstrated superior mechanical properties and deformation stability than their solid-strut lattice structure counterparts. The underlying deformation mechanism analysis revealed that the remarkably enhanced bending strength of the gradient hollow-strut lattice structure made significant contributions to its mechanical performance improvement. This study is envisaged to shed light on future hollow-strut metal lattice structure design for lightweight applications, with the final aim of enhancing the component's mechanical properties and/or lowering its density as compared with the solid-strut lattice structures.

3.
Nat Commun ; 15(1): 3257, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627413

RESUMO

Biological nervous system outperforms in both dynamic and static information perception due to their capability to integrate the sensing, memory and processing functions. Reconfigurable neuromorphic transistors, which can be used to emulate different types of biological analogues in a single device, are important for creating compact and efficient neuromorphic computing networks, but their design remains challenging due to the need for opposing physical mechanisms to achieve different functions. Here we report a neuromorphic electrolyte-gated transistor that can be reconfigured to perform physical reservoir and synaptic functions. The device exhibits dynamics with tunable time-scales under optical and electrical stimuli. The nonlinear volatile property is suitable for reservoir computing, which can be used for multimodal pre-processing. The nonvolatility and programmability of the device through ion insertion/extraction achieved via electrolyte gating, which are required to realize synaptic functions, are verified. The device's superior performance in mimicking human perception of dynamic and static multisensory information based on the reconfigurable neuromorphic functions is also demonstrated. The present study provides an exciting paradigm for the realization of multimodal reconfigurable devices and opens an avenue for mimicking biological multisensory fusion.

4.
Nat Mater ; 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589541

RESUMO

Robust ferroelectricity in nanoscale fluorite oxide-based thin films enables promising applications in silicon-compatible non-volatile memories and logic devices. However, the polar orthorhombic (O) phase of fluorite oxides is a metastable phase that is prone to transforming into the ground-state non-polar monoclinic (M) phase, leading to macroscopic ferroelectric degradation. Here we investigate the reversibility of the O-M phase transition in ZrO2 nanocrystals via in situ visualization of the martensitic transformation at the atomic scale. We reveal that the reversible shear deformation pathway from the O phase to the monoclinic-like (M') state, a compressive-strained M phase, is protected by 90° ferroelectric-ferroelastic switching. Nevertheless, as the M' state gradually accumulates localized strain, a critical tensile strain can pin the ferroelastic domain, resulting in an irreversible M'-M strain relaxation and the loss of ferroelectricity. These findings demonstrate the key role of ferroelastic switching in the reversibility of phase transition and also provide a tensile-strain threshold for stabilizing the metastable ferroelectric phase in fluorite oxide thin films.

5.
Micromachines (Basel) ; 15(3)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38542635

RESUMO

This paper introduces the structure and characteristics of an internal-matching high-power Doherty power amplifier based on GaN HEMT devices with 0.25 µm process platforms from the Nanjing Electronic Devices Institute. Through parameter extraction and load-pull testing of the model transistor, an EE_HEMT model for the 1.2 mm gate-width GaN HEMT device was established. This model serves as the foundation for designing a high-power three-stage Doherty power amplifier. The amplifier achieved a saturated power gain exceeding 9 dB in continuous wave mode, with a saturated power output of 49.7 dBm. The drain efficiency was greater than 65% at 2.6 GHz. At 9 dB power back-off point, corresponding to an output power of 40.5 dBm, the drain efficiency remained above 55%. The performance of the amplifier remains consistent within the 2.55-2.62 GHz frequency range. The measured power, efficiency, and gain of the designed Doherty power amplifier align closely with the simulation results based on the EE_HEMT model, validating the accuracy of the established model. Furthermore, the in-band matching design reduces the size and weight of the amplifier. The amplifier maintains normal operation even after high and low-temperature testing, demonstrating its reliability. In conjunction with DPD (digital pre-distortion) for the modulated signal test, the amplifier exhibits extremely high linearity (ACLR < -50.93 dBc). This Doherty power amplifier holds potential applications in modern wireless communication scenarios.

6.
Light Sci Appl ; 13(1): 67, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443377

RESUMO

High-performance active terahertz modulators as the indispensable core components are of great importance for the next generation communication technology. However, they currently suffer from the tradeoff between modulation depth and speed. Here, we introduce two-dimensional (2D) tellurium (Te) nanofilms with the unique structure as a new class of optically controlled terahertz modulators and demonstrate their integrated heterojunctions can successfully improve the device performances to the optimal and applicable levels among the existing all-2D broadband modulators. Further photoresponse measurements confirm the significant impact of the stacking order. We first clarify the direction of the substrate-induced electric field through first-principles calculations and uncover the unusual interaction mechanism in the photoexcited carrier dynamics associated with the charge transfer and interlayer exciton recombination. This advances the fundamental and applicative research of Te nanomaterials in high-performance terahertz optoelectronics.

7.
Nat Commun ; 15(1): 1693, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402226

RESUMO

Conventional circuit elements are constrained by limitations in area and power efficiency at processing physical signals. Recently, researchers have delved into high-order dynamics and coupled oscillation dynamics utilizing Mott devices, revealing potent nonlinear computing capabilities. However, the intricate yet manageable population dynamics of multiple artificial sensory neurons with spatiotemporal coupling remain unexplored. Here, we present an experimental hardware demonstration featuring a capacitance-coupled VO2 phase-change oscillatory network. This network serves as a continuous-time dynamic system for sensory pre-processing and encodes information in phase differences. Besides, a decision-making module for special post-processing through software simulation is designed to complete a bio-inspired dynamic sensory system. Our experiments provide compelling evidence that this transistor-free coupling network excels in sensory processing tasks such as touch recognition and gesture recognition, achieving significant advantages of fewer devices and lower energy-delay-product compared to conventional methods. This work paves the way towards an efficient and compact neuromorphic sensory system based on nano-scale nonlinear dynamics.

8.
ACS Appl Mater Interfaces ; 16(10): 13247-13257, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38411594

RESUMO

Optical modulation through interface doping offers a convenient and efficient way to control ferroelectric polarization, thereby advancing the utilization of ferroelectric heterostructures in nanoelectronic and optoelectronic devices. In this work, we fabricated heterostructures of MoTe2/BaTiO3/La0.7Sr0.3MnO3 (MoTe2/BTO/LSMO) and demonstrated opposite ultraviolet (UV) light-induced polarization switching behaviors depending on the varied thicknesses of MoTe2. The thickness-dependent band structure of MoTe2 film results in interface doping with opposite polarity in the respective heterostructures. The polarization field of BTO interacts with the interface charges, and an enhanced effective built-in field (Ebi) can trigger the transfer of massive UV light-induced carriers in both MoTe2 and BTO films. As a result, the interplay among the contact field of MoTe2/BTO, the polarization field, and the optically excited carriers determines the UV light-induced polarization switching behavior of the heterostructures. In addition, the electric transport characteristics of MoTe2/BTO/LSMO heterostructures reveal the interface barrier height and Ebi under opposite polarization states, as well as the presence of inherent in-gap trap states in MoTe2 and BTO films. These findings represent a further step toward achieving multifield modulation of the ferroelectric polarization and promote the potential applications in optoelectronic, logic, memory, and synaptic ferroelectric devices.

9.
Nat Commun ; 14(1): 7176, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37935751

RESUMO

Reservoir computing can more efficiently be used to solve time-dependent tasks than conventional feedforward network owing to various advantages, such as easy training and low hardware overhead. Physical reservoirs that contain intrinsic nonlinear dynamic processes could serve as next-generation dynamic computing systems. High-efficiency reservoir systems require nonlinear and dynamic responses to distinguish time-series input data. Herein, an interface-type dynamic transistor gated by an Hf0.5Zr0.5O2 (HZO) film was introduced to perform reservoir computing. The channel conductance of Mott material La0.67Sr0.33MnO3 (LSMO) can effectively be modulated by taking advantage of the unique coupled property of the polarization process and oxygen migration in hafnium-based ferroelectrics. The large positive value of the oxygen vacancy formation energy and negative value of the oxygen affinity energy resulted in the spontaneous migration of accumulated oxygen ions in the HZO films to the channel, leading to the dynamic relaxation process. The modulation of the channel conductance was found to be closely related to the current state, identified as the origin of the nonlinear response. In the time series recognition and prediction tasks, the proposed reservoir system showed an extremely low decision-making error. This work provides a promising pathway for exploiting dynamic ion systems for high-performance neural network devices.

10.
Curr Neurovasc Res ; 20(4): 453-463, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37817523

RESUMO

BACKGROUND: The AKT/mTOR/p70S6K pathway has been shown to potentially promote spinal cord injury (SCI) repair in rats. However, its exact mechanism and beyond needs to be further explored. OBJECTIVE: This study aims to explore the AKT/mTOR/p70S6K pathway in oligodendrocyte precursor cell (OPC) differentiation, microglial polarization differentiation, and the role of these in myelin regeneration in vitro. METHODS: The isolation, induction and characterization of rat primary neuronal stem cells, OPCs and oligodendrocytes were investigated with immunofluorescence and RT-qPCR. Then, the role of AKT/mTOR/p70S6K signaling was explored using western blotting and immunofluorescence, the effect on myelination was examined with OPC-dorsal root ganglion (DRG) neurons co-culture, and the influence of M1/M2 polarization status of microglia on myelin formation was also observed by adding M1/M2 supernatants into OPC-DRG neurons co-culture. RESULTS: Activation of the AKT/mTOR/p70S6K pathway elevated the expression of oligodendrocyte differentiation markers, including MBP, PLP and MOG, which also promoted the colocalization of MBP and NFH in OPC-DRG neurons co-culture. More interestingly, stimulation of the AKT/mTOR/p70S6K pathway facilitated M2 polarization of rat microglia. M2 polarization of microglia enhanced OPC differentiation to oligodendrocytes and myelin formation. CONCLUSION: Our findings highlight the potential of targeting the AKT/mTOR/p70S6K pathway in promoting oligodendrocyte differentiation and myelin regeneration in neurological disorders such as SCI.


Assuntos
Bainha de Mielina , Traumatismos da Medula Espinal , Ratos , Animais , Bainha de Mielina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/farmacologia , Ratos Sprague-Dawley , Serina-Treonina Quinases TOR/metabolismo , Oligodendroglia/metabolismo , Diferenciação Celular , Traumatismos da Medula Espinal/metabolismo
11.
Int J Gen Med ; 16: 3435-3445, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37587978

RESUMO

Background: Laparoscopic cholecystectomy (LC) with laparoscopic common bile duct exploration (LCBDE) is convenient in treating cholelithiasis and choledocholithiasis due to its advantage of accelerated recovery. This retrospective study aimed to summarize the experience of cholelithiasis and choledocholithiasis treatment via three-port approach of LCBDE in Eastern China. Methods: Patients diagnosed with cholelithiasis and choledocholithiasis between July 2019 and October 2021 were included. Patients who received LC+LCBDE+primary suturing of the common bile duct (CBD) via a three-port approach were assigned to the LCBDE-P group, and those who received LC+LCBDE+T-tube drainage of CBD comprised the LCBDE-T group. The measurement data were compared between the two groups. P-values <0.05 indicated statistical significance. Results: A total of 88 patients were divided into two groups: LCBDE-P (n=50) and LCBDE-T (n=38). Multiple logistic regression analysis showed that LCBDE-P is associated with a shorter length of stay (OR=0.115, 95% CI: 0.040-0.329, P<0.001) and lower hospitalization costs (OR=0.120, 95% CI: 0.041-0.357, P<0.001). No significant differences between the two groups were detected in the operation time, intraoperative hemorrhage, clearance rate of CBD stones, postoperative liver function, and postoperative complications (P>0.05). Conclusion: The three-port approach of LCBDE is a safe and feasible strategy for managing cholelithiasis and choledocholithiasis. Compared to LCBDE-T, LCBDE-P reduces the length of hospital stay and medical costs during hospitalization.

12.
Ther Clin Risk Manag ; 19: 657-666, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37575687

RESUMO

Objective: Although laparoscopic repair has been widely carried out and promoted due to its minimally invasive advantages, open surgery is still popular compared to elderly patients. This study aims to compare the outcomes of laparoscopic (LIHR) vs open repair of inguinal hernias (OIHR) in elderly patients. Methods: A retrospective analysis of the database was performed to identify elderly patients, from January 2021 through December 2022, who underwent surgery for an inguinal hernia. After a 1:1 propensity score matching (PSM) with a caliper of 0.1 was conducted to balance potential bias, binary logistic regressions were used for categorical and continuous outcomes. Results: After PSM, 78 pairs of elderly patients were enrolled in this study, and there were no significant differences in baseline between LIHR and OIHR groups. Compared to OIHR, univariable and multivariable logistic regression analysis showed that LIHR was independently affected for reducing intraoperative hemorrhage (OR = 0.06, 95% CI: 0.02-0.18, P < 0.001) and shortening postoperative hospitalization time (OR = 0.29, 95% CI: 0.15-0.57, P < 0.001) in elderly patients. Furthermore, LIHR (OR = 0.28, 95% CI: 0.14-0.57, P < 0.001) and age (OR = 0.89, 95% CI: 0.82-0.96, P = 0.002) were independent affecting factors for relieving postoperative pain. Meanwhile, no obvious differences were detected in postoperative complications [LIHR 7.7% (6/78) vs OIHR 14.1% (11/78), P = 0.199]. Conclusion: LIHR was closely associated with reducing intraoperative hemorrhage and shortening postoperative hospitalization time. Whilst LIHR and age were independently affecting factors for relieving postoperative pain.

13.
Sci Bull (Beijing) ; 68(16): 1757-1763, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37507260

RESUMO

The study of phonon polaritons in van der Waals materials at the nanoscale has gained significant attention in recent years due to its potential applications in nanophotonics. The unique properties of these materials, such as their ability to support sub-diffraction imaging, sensing, and hyperlenses, have made them a promising avenue for the development of new techniques in the field. Despite these advancements, there still exists a challenge in achieving dynamically reversible manipulation of phonon polaritons in these materials due to their insulating properties. In this study, we present experimental results on the reversible manipulation of anisotropic phonon polaritons in α-MoO3 on top of a VO2 film, a phase-change material known for its dramatic changes in dielectric properties between its insulating and metallic states. Our findings demonstrate that the engineered VO2 film enables a switch in the propagation of polaritons in the mid-infrared region by modifying the dielectric properties of the film through temperature changes. Our results represent a promising approach to effectively control the flow of light energy at the nanoscale and offer the potential for the design and fabrication of integrated, flat sub-diffraction polaritonic devices. This study adds to the growing body of work in the field of nanophotonics and highlights the importance of considering phase-change materials for the development of new techniques in this field.

14.
Nat Commun ; 14(1): 3695, 2023 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-37344448

RESUMO

Physiological signal processing plays a key role in next-generation human-machine interfaces as physiological signals provide rich cognition- and health-related information. However, the explosion of physiological signal data presents challenges for traditional systems. Here, we propose a highly efficient neuromorphic physiological signal processing system based on VO2 memristors. The volatile and positive/negative symmetric threshold switching characteristics of VO2 memristors are leveraged to construct a sparse-spiking yet high-fidelity asynchronous spike encoder for physiological signals. Besides, the dynamical behavior of VO2 memristors is utilized in compact Leaky Integrate and Fire (LIF) and Adaptive-LIF (ALIF) neurons, which are incorporated into a decision-making Long short-term memory Spiking Neural Network. The system demonstrates superior computing capabilities, needing only small-sized LSNNs to attain high accuracies of 95.83% and 99.79% in arrhythmia classification and epileptic seizure detection, respectively. This work highlights the potential of memristors in constructing efficient neuromorphic physiological signal processing systems and promoting next-generation human-machine interfaces.


Assuntos
Epilepsia , Redes Neurais de Computação , Humanos , Arritmias Cardíacas , Convulsões , Processamento de Sinais Assistido por Computador
15.
Small ; 19(43): e2304146, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37356048

RESUMO

The quantum phase transition caused by regulating the electronic correlation in strongly correlated quantum materials has been a research hotspot in condensed matter science. Herein, a photon-induced quantum phase transition from the Kondo-Mott insulating state to the low temperature metallic one accompanying with the magnetoresistance changing from negative to positive in the infinite-layer NdNiO2 films is reported, where the antiferromagnetic coupling among the Ni1+ localized spins and the Kondo effect are effectively suppressed by manipulating the correlation of Ni-3d and Nd-5d electrons under the photoirradiation. Moreover, the critical temperature Tc of the superconducting-like transition exhibits a dome-shaped evolution with the maximum up to ≈42 K, and the electrons dominate the transport process proved by the Hall effect measurements. These findings not only make the photoinduction a promising way to control the quantum phase transition by manipulating the electronic correlation in Mott-like insulators, but also shed some light on the possibility of the superconducting in electron-doped nickelates.

16.
Adv Mater ; 35(28): e2207736, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37044111

RESUMO

Unconventional ferroelectricity in fluorite-structure oxides enables tremendous opportunities in nanoelectronics owing to their superior scalability and silicon compatibility. However, their polarization order and switching process remain elusive due to the challenges of visualizing oxygen ions in nanocrystalline films. In this work, the oxygen shifting during polarization switching and correlated polar-nonpolar phase transitions are directly captured among multiple metastable phases in freestanding ZrO2 thin films by low-dose integrated differential phase-contrast scanning transmission electron microscopy (iDPC-STEM). Bidirectional transitions between antiferroelectric and ferroelectric orders and interfacial polarization relaxation are clarified at unit-cell scale. Meanwhile, polarization switching is strongly correlated with Zr-O displacement in reversible martensitic transformation between monoclinic and orthorhombic phases and two-step tetrahedral-to-orthorhombic phase transition. These findings provide atomic insights into the transition pathways between metastable polymorphs and unravel the evolution of polarization orders in (anti)ferroelectric fluorite oxides.


Assuntos
Nanopartículas , Neutrófilos , Óxidos , Oxigênio , Transição de Fase
17.
BMC Musculoskelet Disord ; 24(1): 276, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37038169

RESUMO

BACKGROUND: This study was performed to investigate the clinical efficacy of percutaneous kyphoplasty (PKP) for vertebral compression fractures with different bone mineral densities (BMD). METHODS: We performed a retrospective analysis of 232 patients with single-segment vertebral compression fractures who underwent PKP. Patients were divided into the normal BMD, osteopenia, and osteoporosis groups according to their average lumbar BMD before surgery. The visual analog scale (VAS) was used to compare differences in pain relief before and after surgery in each group. Corrections of the wedge angle and kyphotic angle before and after surgery were observed using anteroposterior and lateral radiographs and compared among the groups, as was the incidence of bone cement leakage. RESULTS: Patients were followed up for 6-12 months, with an average follow-up time of 9.12 ± 1.68 months. The VAS score, wedge angle, and kyphotic angle of the three groups of patients decreased significantly at the end of the follow-up (P < 0.05). The changes in VAS score and wedge angle correction in the osteoporosis group were significantly larger than those in the normal BMD and osteopenia groups (P < 0.05). There were no significant differences among the three groups in terms of kyphotic angle correction or bone cement leakage rates (P > 0.05). CONCLUSIONS: PKP has a positive effect on vertebral compression fractures with different BMD, and is especially suitable for osteoporotic vertebral compression fractures.


Assuntos
Fraturas por Compressão , Cifoplastia , Cifose , Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Humanos , Cifoplastia/efeitos adversos , Estudos Retrospectivos , Fraturas por Compressão/diagnóstico por imagem , Fraturas por Compressão/cirurgia , Fraturas por Compressão/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/complicações , Densidade Óssea , Cimentos Ósseos/uso terapêutico , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/cirurgia , Fraturas por Osteoporose/etiologia , Osteoporose/complicações , Resultado do Tratamento , Cifose/diagnóstico por imagem , Cifose/etiologia , Cifose/cirurgia
18.
Nat Commun ; 14(1): 2274, 2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37080982

RESUMO

Magnetoelectric coupling, as a fundamental physical nature and with the potential to add functionality to devices while also reducing energy consumption, has been challenging to be probed in freestanding membranes or two-dimensional materials due to their instability and fragility. In this paper, we report a magnetoelectric coupling probed by optical second harmonic generation with external magnetic field, and show the manipulation of the ferroelectric and antiferromagnetic orders by the magnetic and thermal fields in BiFeO3 films epitaxially grown on the substrates and in the freestanding ones. Here we define an optical magnetoelectric-coupling constant, denoting the ability of controlling light-induced nonlinear polarization by the magnetic field, and found the magnetoelectric-coupling was suppressed by strain releasing but remain robust against thermal fluctuation for freestanding BiFeO3.

19.
J Phys Condens Matter ; 35(20)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36881920

RESUMO

HfO2-based ferroelectrics, such as Hf0.5Zr0.5O2, arouse great attention in recent years because of their CMOS compatibility and robust nano-scale ferroelectricity. However, fatigue is one of the toughest problems for ferroelectric applications. The fatigue mechanism of HfO2-based ferroelectrics is different from conventional ferroelectric materials, and research on the fatigue mechanism in HfO2-based epitaxial films have been rarely reported. In this work, we fabricate 10 nm Hf0.5Zr0.5O2epitaxial films and investigate the fatigue mechanism. The experimental data show that the remanent ferroelectric polarization value decreased by 50% after 108cycles. It is worth noting that the fatigued Hf0.5Zr0.5O2epitaxial films can be recovered through applying electric stimulus. Combined with the temperature-dependent endurance analysis, we propose that fatigue of our Hf0.5Zr0.5O2films comes from both phase transition between ferroelectric Pca21and antiferroelectric Pbca as well as defects generation and dipole pinned. This result offers a fundamental understanding of HfO2-based film system, and could provide an important guideline for subsequent studies and future applications.

20.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 35(2): 152-157, 2023 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-36916375

RESUMO

OBJECTIVE: To observe the expression of deleted in malignant brain tumor protein 1 (DMBT1) in rat acute respiratory distress syndrome (ARDS) model induced by sepsis and its relationship with ARDS related biomarkers. METHODS: Forty-eight healthy male rats were randomly divided into sham operation group (Sham group) and ARDS model group, and the rats in each group were further divided into three subgroups at 6, 12 and 24 hours after operation, with 8 rats in each subgroup. The rats in the Sham group were exposed to the cecum only, and sepsis induced ARDS model was reproduced by cecal ligation and puncture (CLP) in the ARDS model group. The general performance was observed at 6, 12, 24 hours after operation. Abdominal aortic blood of rats was collected, and the levels of DMBT1, surfactant-associated protein D (SP-D), vascular endothelial growth factor (VEGF), interleukins (IL-6, IL-10) in serum were determined by enzyme-linked immunosorbent assay (ELISA). The lung tissues were collected, and the lung wet/dry weight (W/D) ratio was determined. The lung tissue pathological changes were observed under light microscope after hematoxylin-eosin (HE) staining, and the lung tissue injury score was evaluated. The expression of DMBT1 protein in lung tissue was determined by Western blotting. The relationship between the serum DMBT1 and SP-D, VEGF, IL-6, IL-10, lung tissue injury score were analyzed by Pearson correlation analysis. RESULTS: Rats in the ARDS model group showed obvious pathological manifestations after operation. The alveolar structure destruction, inflammatory cell infiltration, and alveolar hemorrhage were observed under microscope. Compared with the Sham group, the lung tissue injury score and the lung W/D ratio at 12 hours after operation in the ARDS model group were significantly increased (lung tissue injury score: 3.35±0.13 vs. 1.16±0.07, lung W/D ratio: 5.36±0.44 vs. 4.38±0.35, both P < 0.05), and pulmonary edema was present, which suggested that the ARDS model caused by CLP was successfully reproduced. The results of ELISA and Western blotting showed that the levels of serum DMBT1, SP-D, VEGF and IL-6 in the ARDS model group increased gradually with time, while the level of IL-10 increased first and then decreased. Compared with the Sham group, the levels of DMBT1 in serum and the expressions of DMBT1 protein in lung tissue in the ARDS model group were significantly increased from 6 hours after operation [serum (ng/L) : 231.96±19.17 vs. 187.44±10.19, lung tissue (DMBT1/ß-actin): 2.05±0.19 vs. 0.93±0.25, both P < 0.05], and the levels of SP-D, VEGF, IL-6 and IL-10 in serum were significantly increased from 12 hours after operation [SP-D (ng/L): 73.35±8.05 vs. 43.28±5.77, VEGF (ng/L): 89.85±8.47 vs. 43.19±5.11, IL-6 (ng/L): 36.01±2.48 vs. 17.49±1.77, IL-10 (ng/L): 84.55±8.41 vs. 39.83±5.02, all P < 0.05]. Pearson correlation analysis showed that serum DMBT1 was positively correlated with serum SP-D, VEGF, IL-6, IL-10 and lung injury score at 12 hours and 24 hours in the ARDS model group (12 hours: r values were 0.946, 0.942, 0.931, 0.936, 0.748, respectively; 24 hours: r values were 0.892, 0.945, 0.951, 0.918, 0.973, respectively; all P < 0.05). CONCLUSIONS: DMBT1 is a novel early biomarker of ARDS by affecting alveolar epithelial cell, alveolar capillary permeability and inflammatory response.


Assuntos
Síndrome do Desconforto Respiratório , Sepse , Ratos , Masculino , Animais , Interleucina-10 , Fator A de Crescimento do Endotélio Vascular , Interleucina-6 , Proteína D Associada a Surfactante Pulmonar , Fator de Necrose Tumoral alfa
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