Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Eur J Pharm Biopharm ; 198: 114258, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479561

RESUMO

The emergence of drug-resistant bacteria makes antibiotics inadequate to treat bacterial infections, which is now a global problem. Phage as a virus with specific recognition ability can effectively kill the bacteria, which is an efficacious antibacterial material to replace antibiotics. Phage-based hydrogels have good biocompatibility and antibacterial effect at the site of infection. Phage hydrogels have remarkable antibacterial effects on targeted bacteria because of their specific targeted bactericidal ability, but there are few reports and reviews on phage hydrogels. This paper discusses the construction method of phage-based antibacterial hydrogels (PAGs), summarizes the advantages related to PAGs and their applications in the direction of wound healing, treating bone bacterial infections, gastrointestinal infection treatment and other application, and finally gives an outlook on the development and research of PAGs.


Assuntos
Infecções Bacterianas , Bacteriófagos , Humanos , Bactérias , Antibacterianos , Hidrogéis
2.
J Mater Chem B ; 12(14): 3392-3403, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38512335

RESUMO

In the face of the serious threat to human health and the economic burden caused by bacterial antibiotic resistance, 2D phosphorus nanomaterials have been widely used as antibacterial agents. Violet phosphorus nanosheets (VPNSs) are an exciting bandgap-adjustable 2D nanomaterial due to their good physicochemical properties, yet the study of VPNS-based antibiotics is still in its infancy. Here, a composite of gold nanorods (AuNRs) loaded onto VPNS platforms (VPNS/AuNR) is constructed to maximize the potential of VPNSs for antimicrobial applications. The loading with AuNRs not only enhances the photothermal performance via a localized surface plasmon resonance (LSPR) effect, but also enhances the light absorption capacity due to the narrowing of the band gap of the VPNSs, thus increasing the ROS generation capacity. The results demonstrate that VPNS/AuNR exhibits outstanding antibacterial properties and good biocompatibility. Attractively, VPNS/AuNR is then extensively tested for treating skin wound infections, suggesting promising in vivo antibacterial and wound-healing features. Our findings may open a novel direction to develop a versatile VPNS-based treatment platform, which can significantly boost the progress of VPNS exploration.


Assuntos
Nanotubos , Fosfenos , Humanos , Ressonância de Plasmônio de Superfície , Nanotubos/química , Antibacterianos/farmacologia , Fósforo
3.
Math Biosci Eng ; 21(3): 4669-4697, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38549344

RESUMO

Segmenting plant organs is a crucial step in extracting plant phenotypes. Despite the advancements in point-based neural networks, the field of plant point cloud segmentation suffers from a lack of adequate datasets. In this study, we addressed this issue by generating Arabidopsis models using L-system and proposing the surface-weighted sampling method. This approach enables automated point sampling and annotation, resulting in fully annotated point clouds. To create the Arabidopsis dataset, we employed Voxel Centroid Sampling and Random Sampling as point cloud downsampling methods, effectively reducing the number of points. To enhance the efficiency of semantic segmentation in plant point clouds, we introduced the Plant Stratified Transformer. This network is an improved version of the Stratified Transformer, incorporating the Fast Downsample Layer. Our improved network underwent training and testing on our dataset, and we compared its performance with PointNet++, PAConv, and the original Stratified Transformer network. For semantic segmentation, our improved network achieved mean Precision, Recall, F1-score and IoU of 84.20, 83.03, 83.61 and 73.11%, respectively. It outperformed PointNet++ and PAConv and performed similarly to the original network. Regarding efficiency, the training time and inference time were 714.3 and 597.9 ms, respectively, which were reduced by 320.9 and 271.8 ms, respectively, compared to the original network. The improved network significantly accelerated the speed of feeding point clouds into the network while maintaining segmentation performance. We demonstrated the potential of virtual plants and deep learning methods in rapidly extracting plant phenotypes, contributing to the advancement of plant phenotype research.


Assuntos
Arabidopsis , Fontes de Energia Elétrica , Redes Neurais de Computação , Fenótipo , Projetos de Pesquisa
4.
IEEE Trans Pattern Anal Mach Intell ; 46(7): 4641-4653, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38329850

RESUMO

Existing deep learning-based video super-resolution (SR) methods usually depend on the supervised learning approach, where the training data is usually generated by the blurring operation with known or predefined kernels (e.g., Bicubic kernel) followed by a decimation operation. However, this does not hold for real applications as the degradation process is complex and cannot be approximated by these idea cases well. Moreover, obtaining high-resolution (HR) videos and the corresponding low-resolution (LR) ones in real-world scenarios is difficult. To overcome these problems, we propose a self-supervised learning method to solve the blind video SR problem, which simultaneously estimates blur kernels and HR videos from the LR videos. As directly using LR videos as supervision usually leads to trivial solutions, we develop a simple and effective method to generate auxiliary paired data from original LR videos according to the image formation of video SR, so that the networks can be better constrained by the generated paired data for both blur kernel estimation and latent HR video restoration. In addition, we introduce an optical flow estimation module to exploit the information from adjacent frames for HR video restoration. Experiments show that our method performs favorably against state-of-the-art ones on benchmarks and real-world videos.

5.
J Cancer ; 15(5): 1314-1327, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356724

RESUMO

Context: As a flavonoid compound, kaempferol has great potential in anti-lung cancer therapy, but the mechanism of its therapeutic effect needs further exploration. Objective: To explore the therapeutic effect of kaempferol on lung cancer, as well as its capability to regulate the gut microbiota and stimulate immune function. Materials & methods: Twenty-four BALB/c mice were divided into four groups. The first two groups, consisting of 12 normal mice, were administered either PBS or Kaempferol (Kaem) via gavage. The remaining 12 mice, which were subcutaneously inoculated with Lewis Lung Carcinoma (LLC) cells, were similarly divided and subjected to the same treatments respectively. The inhibitory effect of kaempferol on xenograft lung cancer models was explored with in vivo experiments, the diversity of gut microbiota was investigated by 16S rDNA sequencing, and the treatment effect on immune cells was quantified using flow cytometry. Results: Kaempferol exerted a significant inhibitory effect on xenograft lung cancer models in vivo. It effectively inhibited the proliferation of LLC cells and significantly activated cytotoxic T cells, natural killer cells, and other immune cells in mice. 16S rRNA sequencing of fecal samples from tumor-bearing mice treated with kaempferol showed a significant increase in the abundances of potentially advantageous microbial species such as c_Bacilli, o_Lactobacillales, f_Lachnospiraceae, s_uncultured_bacterium_g_Lactobacillus, g_Lactobacillus, f_Bacteroidaceae, g_Bacteroides, and s_uncultured_bacterium_g_Bacteroides, s_Bacteroides_acidifaciens. An increase in the proportions of three types of immune cells might associated with the above dominant bacterial species. Conclusion: Kaempferol can inhibit xenograft lung cancer models. Such inhibition effect might come from the activation of T cells, NK cells, and other immune cells which are modulated by the gut microbiota.

6.
Polymers (Basel) ; 15(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37050345

RESUMO

The excessive migration of small molecular plasticizers in solid propellants may lead to debonding and changes in combustion characteristics, affecting the safety of solid rocket motors. Herein, two functionalized graphene oxides (GO) were used to enhance the anti-migration performance of EPDM insulation. GO, 3-Aminopropyltriethoxysilane-modified GO (AGO) and octadecylamine-modified GO (HGO) were filled into EPDM to fabricate EPDM insulation. The anti-migration properties and migration kinetics of EPDM insulations were studied using immersion tests. Moreover, the mechanical properties, including the tensile properties, crosslink density, hardness, and aging resistance of different EPDM insulations, were also explored. Compared with GO, AGO, and HGO obviously enhanced the anti-migration and mechanical properties of the EPDM insulations. This study shows that the anti-migration performance of EPDM insulation can be enhanced by functionalized GO.

7.
IEEE Trans Pattern Anal Mach Intell ; 45(8): 9411-9425, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37022839

RESUMO

We present compact and effective deep convolutional neural networks (CNNs) by exploring properties of videos for video deblurring. Motivated by the non-uniform blur property that not all the pixels of the frames are blurry, we develop a CNN to integrate a temporal sharpness prior (TSP) for removing blur in videos. The TSP exploits sharp pixels from adjacent frames to facilitate the CNN for better frame restoration. Observing that the motion field is related to latent frames instead of blurry ones in the image formation model, we develop an effective cascaded training approach to solve the proposed CNN in an end-to-end manner. As videos usually contain similar contents within and across frames, we propose a non-local similarity mining approach based on a self-attention method with the propagation of global features to constrain CNNs for frame restoration. We show that exploring the domain knowledge of videos can make CNNs more compact and efficient, where the CNN with the non-local spatial-temporal similarity is 3× smaller than the state-of-the-art methods in terms of model parameters while its performance gains are at least 1 dB higher in terms of PSNRs. Extensive experimental results show that our method performs favorably against state-of-the-art approaches on benchmarks and real-world videos.


Assuntos
Algoritmos , Redes Neurais de Computação
8.
ACS Appl Mater Interfaces ; 15(18): 22553-22562, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37098745

RESUMO

The ubiquitous solid-liquid systems in nature usually present an interesting mechanical property, the rate-dependent stiffness, which could be exploited for impact protection in flexible systems. Herein, a typical natural system, the durian peel, has been systematically characterized and studied, showing a solid-liquid dual-phase cellular structure. A bioinspired design of flexible impact-resistant composites is then proposed by combining 3D lattices and shear thickening fluids. The resulting dual-phase composites offer, simultaneously, low moduli (e.g., 71.9 kPa, lower than those of many reported soft composites) under quasi-static conditions and excellent energy absorption (e.g., 425.4 kJ/m3, which is close to those of metallic and glass-based lattices) upon dynamic impact. Numerical simulations based on finite element analyses were carried out to understand the enhanced buffering of the developed composites, unveiling a lattice-guided fluid-structure interaction mechanism. Such biomimetic lattice-based flexible impact-resistant composites hold promising potential for the development of next-generation flexible protection systems that can be used in wearable electronics and robotic systems.

9.
Front Neurosci ; 16: 999240, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312037

RESUMO

The high-performance low-field magnetic resonance imaging (MRI) system, equipped with modern hardware and contemporary imaging capabilities, has garnered interest within the MRI community in recent years. It has also been proven to have unique advantages over high-field MRI in both physical and cost aspects. However, for susceptibility weighted imaging (SWI), the low signal-to-noise ratio and the long echo time inherent at low field hinder the SWI from being applied to clinical applications. This work optimized the imaging protocol to select suitable parameters such as the values of time of echo (TE), repetition time (TR), and the flip angle (FA) of the RF pulse according to the signal simulations for low-field SWI. To improve the signal-to-noise ratio (SNR) performance, averaging multi-echo magnitude images and BM4D phase denoising were proposed. A comparison of the SWI in 0.5T and 1.5T was carried out, demonstrating the capability to identify magnetic susceptibility differences between variable tissues, especially, the blood veins. This would open the possibility to extend SWI applications in the high-performance low field MRI.

10.
Polymers (Basel) ; 14(16)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36015571

RESUMO

The migration of plasticizers such as nitroglycerin seriously affects the storage and working safety of rocket systems. In this work, hydroxy-terminated polybutadiene (HTPB) liner composites with the cross-linked structure were prepared by cross-linking isocyanate functionalized graphene oxide (IGO) with HTPB to prevent the migration of high energy plasticizers in the propellant. IGO was uniformly dispersed in the matrix as reinforcement and cross-linker, providing good migration resistance and ablation resistance for the liner composites. Compared with pure HTPB, the migration resistance of the liner with 0.5 wt% IGO increased by 18.94%, 16.33% and 15.34% at 25 °C, 60 °C and 90 °C, respectively. In addition, the ablation resistance of the HTPB liner was improved by the addition of IGO. The improved anti-migration properties come from the special laminar structure of IGO and the dense molecular chains network of the cross-linked composites.

11.
Rev Sci Instrum ; 93(4): 045102, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35489917

RESUMO

Premature failure of thermal barrier coatings (TBCs) under a temperature gradient is an overriding concern in many applications, and their mechanical parameters are essential to failure analysis. In this study, an in situ micro-indentation apparatus, including a heating module, cooling module, and micro-indentation module, was developed to study the mechanical parameters of TBCs with a temperature gradient. The upper surface of the TBC was heated by radiation to simulate high-temperature service conditions, and the bottom surface was gas-cooled. Different temperature gradients are obtained by changing the velocity of the cooling gas. The temperatures through the thickness of the TBCs were analyzed by numerical simulations and experiments. During exposure to the temperature gradient, micro-indentation tests of the TBC samples were conducted to obtain their mechanical parameters. In situ micro-indentation tests at different cooling gas flow rates (0, 20, and 40 l/min) were performed on the TBCs. The elastic modulus and stress evolution of the TBCs were extracted by analyzing the load-displacement curves at different gas velocities. The elastic modulus remains almost constant with increasing velocity while the stress difference increases.

12.
IEEE Trans Image Process ; 31: 1217-1229, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35015639

RESUMO

We propose an effective image dehazing algorithm which explores useful information from the input hazy image itself as the guidance for the haze removal. The proposed algorithm first uses a deep pre-dehazer to generate an intermediate result, and takes it as the reference image due to the clear structures it contains. To better explore the guidance information in the generated reference image, it then develops a progressive feature fusion module to fuse the features of the hazy image and the reference image. Finally, the image restoration module takes the fused features as input to use the guidance information for better clear image restoration. All the proposed modules are trained in an end-to-end fashion, and we show that the proposed deep pre-dehazer with progressive feature fusion module is able to help haze removal. Extensive experimental results show that the proposed algorithm performs favorably against state-of-the-art methods on the widely-used dehazing benchmark datasets as well as real-world hazy images.

13.
Front Immunol ; 12: 740790, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733279

RESUMO

Background: Hepatocellular carcinoma (HCC) is a common gastrointestinal malignancy with high incidence and poor prognosis. Common treatment methods include surgery, transcatheter arterial chemoembolization (TACE), ablation, and targeted therapy. In recent years, combination treatment with antiangiogenic therapy and immune checkpoint inhibitors has made great progress in the treatment of advanced HCC. Here, we report the case of a patient with HCC who achieved a durable benefit from anti-vascular therapy and immune checkpoint inhibitors combined with intratumoral cryoablation. Main Body: A 38-year-old male patient initially presented with severe abdominal pain that was identified as an HCC rupture and hemorrhage by computed tomography (CT). The patient underwent emergency surgery and postoperative pathology confirmed HCC. The patient received prophylactic TACE after surgery. Unfortunately, three months after surgery, the patient developed multiple liver metastases. Subsequently, he received systemic anti-vascular therapy and immune checkpoint inhibitors combined with intratumoral cryoablation. After treatment, the patient achieved extensive tumor necrosis and the disease was effectively controlled. Conclusions: Anti-angiogenic therapy and immune checkpoint inhibitors combined with cryoablation can induce a powerful and effective systemic anti-tumor immune response, which is worthy of further research.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Hepatocelular/terapia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/métodos , Neoplasias Hepáticas/terapia , Neovascularização Patológica/tratamento farmacológico , Compostos de Fenilureia/uso terapêutico , Quinolinas/uso terapêutico , Adulto , Terapia Combinada , Criocirurgia , Humanos , Masculino , Metástase Neoplásica , Recidiva Local de Neoplasia , Indução de Remissão
14.
Onco Targets Ther ; 14: 3983-3989, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34234467

RESUMO

BACKGROUND: HER2-positive patients with advanced gastric cancer have a poor prognosis, and trastuzumab-resistant patients lack effective treatment. CASE PRESENTATION: We report a 72-year-old male with HER2-positive gastric cancer. The patient had metastatic tumor during adjuvant chemotherapy after surgery, followed by second-line chemotherapy, and achieved a progression-free survival (PFS) of 4.5 months. Subsequent third-line chemotherapy treatment also failed. Fortunately, the patient had a significant tumor response and 8.5 months of PFS on trastuzumab combined with chemotherapy. After trastuzumab resistance, the patient was treated with programmed cell death protein-1 inhibitor combined with apatinib, which selectively inhibited VEGFR2, but the effect was not satisfactory. Finally, the patient was treated with capecitabine combined with pyrotinib, an irreversible TKI, acting on HER2. The tumor shrank significantly after this treatment. CONCLUSION: The mechanism and countermeasures of trastuzumab resistance were discussed in this case. For patients with HER2-positive advanced gastric cancer, pyrotinib can achieve good results after trastuzumab resistance.

15.
Int J Med Sci ; 18(8): 1899-1909, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746607

RESUMO

The morbidity and mortality rates associated with non-small-cell lung carcinoma (NSCLC) are increasing every year, placing new demands on existing therapies and drugs. Ammonium ferric citrate (AFC) is often used as a food additive for iron supplementation; however, to our knowledge, no studies have investigated whether AFC can induce ferroptosis in NSCLC. In this study, we demonstrated that specific concentrations of AFC effectively inhibit the proliferation and invasion of lung cancer cell lines in vitro using a cell proliferation inhibition test, a transwell assay, and flow cytometry analysis of cell cycle and apoptosis. In addition, AFC significantly induced oxidative stress injury in lung cancer cell lines. A quantitative polymerase chain reaction assay showed that AFC markedly reduced the expression levels of cell growth factors, negative regulators of ferroptosis, and autophagy regulators. Lastly, a protein-protein interaction analysis revealed that glutathione peroxidase 4 (GPX4) exerted its biological role through the regulation of the GSS/GSR complex and downstream GGT family proteins. When the expression of GPX4 changes, its biological activities, such as the glutathione metabolic process, cellular biosynthetic process, cellular response to chemical stimulus, and antioxidant activity, change accordingly, thereby affecting the survival quality and physiological and biochemical activities of cells. Overall, this study verifies that AFC has the biological activity of activating oxidative stress injury in NSCLC cell lines, leading to a decrease in their autophagy and inducing ferroptosis. We also confirmed that the GPX4-GSS/GSR-GGT axis is a crucial target of AFC-induced ferroptosis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Compostos Férricos/farmacologia , Ferroptose/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Compostos de Amônio Quaternário/farmacologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Compostos Férricos/uso terapêutico , Glutationa Redutase/metabolismo , Glutationa Sintase/metabolismo , Humanos , Neoplasias Pulmonares/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Compostos de Amônio Quaternário/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , gama-Glutamiltransferase/metabolismo
16.
Front Psychol ; 12: 792550, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35035371

RESUMO

Digital technology has gained momentum in the recent decade, with its relationships with digital entrepreneurship, digital economies, digital social interaction, green economies, etc. These have changed the perspective of business and hence digitalized the strategic policies through blockchains. The current study aims to identify such benefits that have changed the day-to-day life processes and procedures for carrying out different tasks due to the convenience of adopting digital technology. Those benefits have been classified as transparency, centralization, and access to new markets for the organizations considering their consequences, especially when using digital technology. When processes are taking place online, there are fair chances of hiding knowledge about certain products or procedures to gain particular benefits. Hence, this study has considered the moderating role of product knowledge hiding while interacting online. This study is a quantitative post-positivist cross-sectional study that has followed a survey technique for data collection. The population used in this study is the managerial staff of the telecom sector in the mainland in China. The sample size used in this study is 358. The software used in this study is Smart-PLS 3.3. The technique used in this study for data analysis is structural equation modeling with measurement modeling. The findings of this study show that digital technology has led to many benefits for organizations like centralization, access to the new markets, and transparency, which have been made possible remotely only because of the use of digital technology in business operations. However, the moderating role of product knowledge hiding has been found significant only for transparency. This research paper highlights the important benefits of the use of technological use in the corporate world. Also, it contributes to expanding the network of knowledge hiding, addressing the moderation of product knowledge hiding, and extending the known consequences of digital technology influencing knowledge hiding.

17.
Curr Drug Deliv ; 18(2): 234-245, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32811397

RESUMO

OBJECTIVE: This study aimed to fabricate Hyaluronic Acid (HA)/parecoxib-loaded PLGA microspheres for the treatment of Temporomandibular Disorders (TMD) and investigate the in vitro and in vivo effect of the microsphere system to solve the issues of poor drug delivery and short duration on drug concentration in conventional TMD therapy. METHODS: The microspheres were prepared by the double emulsion (w/o/w) method. Various formulations were compared in terms of particle size, drug loading rate and encapsulation rate. Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and FT-IR spectroscopy were performed to evaluate physicochemical properties. The drug release behavior of microspheres and toxicity assay on synovial cells were investigated. The in vitro anti-inflammatory effect on inflammatory markers, such as IL-1ß, TNF-α and COX-2, was assessed by real-time PCR. Then, the in vivo therapeutic effect of microspheres was investigated using mechanically-induced rat synovitis model. Protein levels of inflammatory cytokines (IL-1ß, TNF-α and COX-2) from TMJ periarticular tissues were quantified by Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS: The results showed that microspheres were morphologically regular, smooth and non-cohesive. The average particle size of the microspheres was (25.32 ± 1.01) µm. The drug loading rate of parecoxib was 17.12%-20.95% with encapsulation efficiency reaching 51.9%-54.7%. In vitro drug release tests showed a successful sustained release over 28 days with a burst of 19.98% of the total drug substance. Treatment with HA/parecoxib-loaded PLGA microspheres declined the mRNA expression of IL-1ß, TNF-α and COX-2 induced by LPS in articular synovial cells. Moreover, in vivo results demonstrated that the intra-articular microspheres significantly reduced protein levels of inflammatory cytokines (IL-1ß, TNF-α and COX-2) for more than two weeks and stopped the mechanically-induced synovitis in its tracks in rat models. CONCLUSION: The study presented new and potential insights into treatments of TMD using PLGA microspheres loaded with HA and parecoxib as a successful drug delivery system.


Assuntos
Ácido Hialurônico , Isoxazóis/farmacologia , Transtornos da Articulação Temporomandibular , Animais , Isoxazóis/química , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Transtornos da Articulação Temporomandibular/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...